Lincoln Electric Welding System SVM162 B User Manual
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SVM162-B  
January, 2008  
PRECISION TIG 275  
For use with machines having Code Numbers:  
10806; 10807; 10893; 11158; 11159  
Safety Depends on You  
Lincoln arc welding and cutting  
equipment is designed and built  
with safety in mind. However, your  
overall safety can be increased by  
proper installation ... and thoughtful  
operation on your part. DO NOT  
INSTALL, OPERATE OR REPAIR  
THIS EQUIPMENT WITHOUT  
READING THIS MANUAL AND  
THE SAFETY PRECAUTIONS  
CONTAINED  
THROUGHOUT.  
And, most importantly, think before  
you act and be careful.  
SERVICE MANUAL  
Copyright © Lincoln Global Inc.  
• World's Leader in Welding and Cutting Products •  
• Sales and Service through Subsidiaries and Distributors Worldwide •  
Cleveland, Ohio 44117-1199 U.S.A. TEL: 888-935-3877 FAX: 216.486.1751 WEB SITE: www.lincolnelectric.com  
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ii  
ii  
SAFETY  
ELECTRIC SHOCK can kill.  
ARC RAYS can burn.  
3.a. The electrode and work (or ground) circuits  
are electrically “hot” when the welder is on.  
Do not touch these “hot” parts with your bare  
skin or wet clothing. Wear dry, hole-free  
gloves to insulate hands.  
4.a. Use a shield with the proper filter and cover  
plates to protect your eyes from sparks and  
the rays of the arc when welding or observing  
open arc welding. Headshield and filter lens  
should conform to ANSI Z87. I standards.  
3.b. Insulate yourself from work and ground using dry insulation.  
Make certain the insulation is large enough to cover your full  
area of physical contact with work and ground.  
4.b. Use suitable clothing made from durable flame-resistant  
material to protect your skin and that of your helpers from  
the arc rays.  
4.c. Protect other nearby personnel with suitable, non-flammable  
screening and/or warn them not to watch the arc nor expose  
themselves to the arc rays or to hot spatter or metal.  
In addition to the normal safety precautions, if welding  
must be performed under electrically hazardous  
conditions (in damp locations or while wearing wet  
clothing; on metal structures such as floors, gratings or  
scaffolds; when in cramped positions such as sitting,  
kneeling or lying, if there is a high risk of unavoidable or  
accidental contact with the workpiece or ground) use  
the following equipment:  
FUMES AND GASES  
can be dangerous.  
5.a. Welding may produce fumes and gases  
hazardous to health. Avoid breathing these  
• Semiautomatic DC Constant Voltage (Wire) Welder.  
• DC Manual (Stick) Welder.  
• AC Welder with Reduced Voltage Control.  
fumes and gases.When welding, keep  
your head out of the fume. Use enough  
ventilation and/or exhaust at the arc to keep  
3.c. In semiautomatic or automatic wire welding, the electrode,  
electrode reel, welding head, nozzle or semiautomatic  
welding gun are also electrically “hot”.  
fumes and gases away from the breathing zone. When  
welding with electrodes which require special  
ventilation such as stainless or hard facing (see  
instructions on container or MSDS) or on lead or  
cadmium plated steel and other metals or coatings  
which produce highly toxic fumes, keep exposure as  
low as possible and below Threshold Limit Values (TLV)  
using local exhaust or mechanical ventilation. In  
confined spaces or in some circumstances, outdoors, a  
respirator may be required. Additional precautions are  
also required when welding on galvanized steel.  
3.d. Always be sure the work cable makes a good electrical  
connection with the metal being welded. The connection  
should be as close as possible to the area being welded.  
3.e. Ground the work or metal to be welded to a good electrical  
(earth) ground.  
3.f. Maintain the electrode holder, work clamp, welding cable and  
welding machine in good, safe operating condition. Replace  
damaged insulation.  
5. b. The operation of welding fume control equipment is affected  
by various factors including proper use and positioning of the  
equipment, maintenance of the equipment and the specific  
welding procedure and application involved. Worker expo-  
sure level should be checked upon installation and periodi-  
cally thereafter to be certain it is within applicable OSHA PEL  
and ACGIH TLV limits.  
3.g. Never dip the electrode in water for cooling.  
3.h. Never simultaneously touch electrically “hot” parts of  
electrode holders connected to two welders because voltage  
between the two can be the total of the open circuit voltage  
of both welders.  
5.c. Do not weld in locations near chlorinated hydrocarbon vapors  
coming from degreasing, cleaning or spraying operations.  
The heat and rays of the arc can react with solvent vapors to  
form phosgene, a highly toxic gas, and other irritating prod-  
ucts.  
3.i. When working above floor level, use a safety belt to protect  
yourself from a fall should you get a shock.  
3.j. Also see Items 6.c. and 8.  
5.d. Shielding gases used for arc welding can displace air and  
cause injury or death. Always use enough ventilation,  
especially in confined areas, to insure breathing air is safe.  
5.e. Read and understand the manufacturerʼs instructions for this  
equipment and the consumables to be used, including the  
material safety data sheet (MSDS) and follow your  
employerʼs safety practices. MSDS forms are available from  
your welding distributor or from the manufacturer.  
5.f. Also see item 1.b.  
Aug ʻ06  
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iii  
iii  
SAFETY  
WELDING SPARKS can  
cause fire or explosion.  
CYLINDER may explode  
if damaged.  
6.a. Remove fire hazards from the welding area.  
If this is not possible, cover them to prevent  
7.a. Use only compressed gas cylinders  
containing the correct shielding gas for the  
the welding sparks from starting a fire.  
process used and properly operating  
Remember that welding sparks and hot  
regulators designed for the gas and  
materials from welding can easily go through small cracks  
and openings to adjacent areas. Avoid welding near  
hydraulic lines. Have a fire extinguisher readily available.  
pressure used. All hoses, fittings, etc. should be suitable for  
the application and maintained in good condition.  
7.b. Always keep cylinders in an upright position securely  
chained to an undercarriage or fixed support.  
6.b. Where compressed gases are to be used at the job site,  
special precautions should be used to prevent hazardous  
situations. Refer to “Safety in Welding and Cutting” (ANSI  
Standard Z49.1) and the operating information for the  
equipment being used.  
7.c. Cylinders should be located:  
•Away from areas where they may be struck or subjected to  
physical damage.  
6.c. When not welding, make certain no part of the electrode  
circuit is touching the work or ground. Accidental contact can  
cause overheating and create a fire hazard.  
•A safe distance from arc welding or cutting operations and  
any other source of heat, sparks, or flame.  
7.d. Never allow the electrode, electrode holder or any other  
electrically “hot” parts to touch a cylinder.  
6.d. Do not heat, cut or weld tanks, drums or containers until the  
proper steps have been taken to insure that such procedures  
will not cause flammable or toxic vapors from substances  
inside. They can cause an explosion even though they have  
been “cleaned”. For information, purchase “Recommended  
Safe Practices for the Preparation for Welding and Cutting of  
Containers and Piping That Have Held Hazardous  
Substances”, AWS F4.1 from the American Welding Society  
(see address above).  
7.e. Keep your head and face away from the cylinder valve outlet  
when opening the cylinder valve.  
7.f. Valve protection caps should always be in place and hand  
tight except when the cylinder is in use or connected for  
use.  
7.g. Read and follow the instructions on compressed gas  
cylinders, associated equipment, and CGA publication P-l,  
“Precautions for Safe Handling of Compressed Gases in  
Cylinders,” available from the Compressed Gas Association  
1235 Jefferson Davis Highway, Arlington, VA 22202.  
6.e. Vent hollow castings or containers before heating, cutting or  
welding. They may explode.  
6.f. Sparks and spatter are thrown from the welding arc. Wear oil  
free protective garments such as leather gloves, heavy shirt,  
cuffless trousers, high shoes and a cap over your hair. Wear  
ear plugs when welding out of position or in confined places.  
Always wear safety glasses with side shields when in a  
welding area.  
FOR ELECTRICALLY  
powered equipment.  
6.g. Connect the work cable to the work as close to the welding  
area as practical. Work cables connected to the building  
framework or other locations away from the welding area  
increase the possibility of the welding current passing  
through lifting chains, crane cables or other alternate circuits.  
This can create fire hazards or overheat lifting chains or  
cables until they fail.  
8.a. Turn off input power using the disconnect  
switch at the fuse box before working on  
the equipment.  
8.b. Install equipment in accordance with the U.S. National  
Electrical Code, all local codes and the manufacturerʼs  
recommendations.  
6.h. Also see item 1.c.  
8.c. Ground the equipment in accordance with the U.S. National  
Electrical Code and the manufacturerʼs recommendations.  
Mar ʻ95  
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iv  
iv  
SAFETY  
6. Eloigner les matériaux inflammables ou les recouvrir afin de  
prévenir tout risque dʼincendie dû aux étincelles.  
PRÉCAUTIONS DE SÛRETÉ  
Pour votre propre protection lire et observer toutes les instructions  
et les précautions de sûreté specifiques qui parraissent dans ce  
manuel aussi bien que les précautions de sûreté générales suiv-  
antes:  
7. Quand on ne soude pas, poser la pince à une endroit isolé de  
la masse. Un court-circuit accidental peut provoquer un  
échauffement et un risque dʼincendie.  
8. Sʼassurer que la masse est connectée le plus prés possible de  
la zone de travail quʼil est pratique de le faire. Si on place la  
masse sur la charpente de la construction ou dʼautres endroits  
éloignés de la zone de travail, on augmente le risque de voir  
passer le courant de soudage par les chaines de levage,  
câbles de grue, ou autres circuits. Cela peut provoquer des  
risques dʼincendie ou dʼechauffement des chaines et des  
câbles jusquʼà ce quʼils se rompent.  
Sûreté Pour Soudage A L’Arc  
1. Protegez-vous contre la secousse électrique:  
a. Les circuits à lʼélectrode et à la piéce sont sous tension  
quand la machine à souder est en marche. Eviter toujours  
tout contact entre les parties sous tension et la peau nue  
ou les vétements mouillés. Porter des gants secs et sans  
trous pour isoler les mains.  
b. Faire trés attention de bien sʼisoler de la masse quand on  
soude dans des endroits humides, ou sur un plancher met-  
allique ou des grilles metalliques, principalement dans  
les positions assis ou couché pour lesquelles une grande  
partie du corps peut être en contact avec la masse.  
c. Maintenir le porte-électrode, la pince de masse, le câble de  
soudage et la machine à souder en bon et sûr état defonc-  
tionnement.  
9. Assurer une ventilation suffisante dans la zone de soudage.  
Ceci est particuliérement important pour le soudage de tôles  
galvanisées plombées, ou cadmiées ou tout autre métal qui  
produit des fumeés toxiques.  
10. Ne pas souder en présence de vapeurs de chlore provenant  
dʼopérations de dégraissage, nettoyage ou pistolage. La  
chaleur ou les rayons de lʼarc peuvent réagir avec les vapeurs  
du solvant pour produire du phosgéne (gas fortement toxique)  
ou autres produits irritants.  
d.Ne jamais plonger le porte-électrode dans lʼeau pour le  
refroidir.  
e. Ne jamais toucher simultanément les parties sous tension  
des porte-électrodes connectés à deux machines à souder  
parce que la tension entre les deux pinces peut être le total  
de la tension à vide des deux machines.  
f. Si on utilise la machine à souder comme une source de  
courant pour soudage semi-automatique, ces precautions  
pour le porte-électrode sʼapplicuent aussi au pistolet de  
soudage.  
11. Pour obtenir de plus amples renseignements sur la sûreté, voir  
le code “Code for safety in welding and cutting” CSA Standard  
W 117.2-1974.  
PRÉCAUTIONS DE SÛRETÉ POUR  
LES MACHINES À SOUDER À  
TRANSFORMATEUR ET À  
REDRESSEUR  
2. Dans le cas de travail au dessus du niveau du sol, se protéger  
contre les chutes dans le cas ou on recoit un choc. Ne jamais  
enrouler le câble-électrode autour de nʼimporte quelle partie du  
corps.  
3. Un coup dʼarc peut être plus sévère quʼun coup de soliel, donc:  
a. Utiliser un bon masque avec un verre filtrant approprié ainsi  
quʼun verre blanc afin de se protéger les yeux du rayon-  
nement de lʼarc et des projections quand on soude ou  
quand on regarde lʼarc.  
b. Porter des vêtements convenables afin de protéger la peau  
de soudeur et des aides contre le rayonnement de lʻarc.  
c. Protéger lʼautre personnel travaillant à proximité au  
soudage à lʼaide dʼécrans appropriés et non-inflammables.  
1. Relier à la terre le chassis du poste conformement au code de  
lʼélectricité et aux recommendations du fabricant. Le dispositif  
de montage ou la piece à souder doit être branché à une  
bonne mise à la terre.  
2. Autant que possible, Iʼinstallation et lʼentretien du poste seront  
effectués par un électricien qualifié.  
3. Avant de faires des travaux à lʼinterieur de poste, la debranch-  
er à lʼinterrupteur à la boite de fusibles.  
4. Des gouttes de laitier en fusion sont émises de lʼarc de  
soudage. Se protéger avec des vêtements de protection libres  
de lʼhuile, tels que les gants en cuir, chemise épaisse, pan-  
talons sans revers, et chaussures montantes.  
4. Garder tous les couvercles et dispositifs de sûreté à leur place.  
5. Toujours porter des lunettes de sécurité dans la zone de  
soudage. Utiliser des lunettes avec écrans lateraux dans les  
zones où lʼon pique le laitier.  
Mar ʻ93  
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v
v
MASTER TABLE OF CONTENTS FOR ALL SECTIONS  
RETURN TO MAIN MENU  
X  
Page  
Safety.................................................................................................................................................i-iv  
Installation.............................................................................................................................Section A  
Operation...............................................................................................................................Section B  
Accessories ..........................................................................................................................Section C  
Maintenance..........................................................................................................................Section D  
Theory of Operation .............................................................................................................Section E  
Troubleshooting and Repair ................................................................................................Section F  
How to Use Troubleshooting Guide ............................................................................................F-2  
Safety Precautions ......................................................................................................................F-3  
Troubleshooting Guide ................................................................................................................F-4  
Test Procedures ........................................................................................................................F-19  
Oscilloscope Waveforms...........................................................................................................F-39  
Replacement Procedures .........................................................................................................F-45  
Retest After Repair....................................................................................................................F-61  
Electrical Diagrams..............................................................................................................Section G  
Parts Manual ........................................................................................................P404 & P558 Series  
PRECISION TIG 275  
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A-1  
A-1  
TABLE OF CONTENTS  
- INSTALLATION SECTION -  
Installation  
Technical Specifications..............................................................................................................A-2  
Rated Output...............................................................................................................................A-3  
Additional Output Capacity .........................................................................................................A-3  
Wire and Fuse Sizes...................................................................................................................A-3  
Physical Dimensions...................................................................................................................A-3  
Temperature Ranges ..................................................................................................................A-3  
Safety Precautions......................................................................................................................A-4  
Stacking ......................................................................................................................................A-4  
Lifting and Moving.......................................................................................................................A-4  
Tilting...........................................................................................................................................A-4  
High Frequency Interference Protection.....................................................................................A-4  
Input Electrical Connections .......................................................................................................A-5  
Ground Connection...............................................................................................................A-5  
Output Cables, Connections & Limitations.................................................................................A-6  
TIG Torch Connection.................................................................................................................A-7  
Auxiliary Power Connections......................................................................................................A-8  
Remote Control...........................................................................................................................A-8  
Robotic Interface Connection .....................................................................................................A-9  
PRECISION TIG 275  
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A-2  
A-2  
INSTALLATION  
TECHNICAL SPECIFICATIONS-PRECISION TIG 275 (Domestic, Canadian & Export  
RATED INPUT - SINGLE PHASE ONLY  
Duty Cycle-Applications  
Voltage + 10%  
Max. Amps With Out  
Max. Amps With  
K
Power Factor Capacitor  
Power Factor Capacitor  
Number  
40%  
AC/DC Stick / Balance TIG  
104/94/47  
80/72/36  
95/86/43  
K1825-1  
K1826-1  
K2619-1  
#
Unbalance (70% Penetration ) AC TIG  
124/112/56  
60%  
AC/DC Stick / Balance TIG  
86/78/39  
95/86/43  
64/58/29  
62/56/28  
#
Unbalance (70% Penetration ) AC TIG  
208/230/460  
R
100%  
AC/DC Stick / Balance TIG  
77/70/35  
73/66/33  
6/5/3  
55/50/25  
40/36/18  
36/32/16  
#
Unbalance (70% Penetration ) AC TIG  
NRTL/C  
Idle Amps  
40%  
AC/DC Stick / Balance TIG  
47/38  
56/45  
35/28  
43/34  
K1826-2  
K2619-2  
#
Unbalance (70% Penetration ) AC TIG  
60%  
AC/DC Stick / Balance TIG  
39/31  
43/35  
29/23  
28/23  
#
Unbalance (70% Penetration ) AC TIG  
100%  
460/575  
R
AC/DC Stick / Balance TIG  
35/28  
33/26  
3/2  
25/20  
18/14  
16/13  
500W  
#
Unbalance (70% Penetration ) AC TIG  
NRTL/C  
Idle Amps  
Idle Power  
300W  
40%  
95/55/50  
AC/DC Stick / Balance TIG  
80/46/43  
86/50/46  
#
109/63/58  
Unbalance (70% Penetration ) AC TIG  
60%  
80/46/42  
85/49/45  
AC/DC Stick / Balance TIG  
64/37/34  
67/39/36  
#
Unbalance (70% Penetration ) AC TIG  
220-230/  
K1827-1  
100%  
380-400/415  
70/41/37  
65/38/35  
10/6/5  
AC/DC Stick / Balance TIG  
52/30/28  
46/27/25  
23/13/12  
500W  
#
Unbalance (70% Penetration ) AC TIG  
N80  
Idle Amps  
Idle Power  
IEC 60974-1  
400W  
K1825-1,K1826-1 & K1826-2  
K1827-1  
.63 min.  
.65 min.  
.85 min.  
.77 min.  
RATED POWER FACTOR (STICK)  
RATED OUTPUT - NEMA EW1 Class ll (40) K1825-1,K1826-1,-2, K2619-1.-2  
Duty Cycle-Applications  
40%  
Volts at Rated Amperes  
Amps  
AC/DC Stick / Balance TIG  
31.0  
16.1  
275  
255  
#
Unbalance (70% Penetration ) AC TIG  
60%  
AC/DC Stick / Balance TIG  
29.0  
15.4  
225  
200  
#
Unbalance (70% Penetration ) AC TIG  
100%  
AC/DC Stick / Balance TIG  
28.0  
14.8  
200  
150  
#
Unbalance (70% Penetration ) AC TIG  
*Shown on Front of this IM manual with Under-Cooler Cart and Advanced Control Panel (Refer to Optional Equipment)  
#Exceeds NEMA Unbalanced Load Specification comparable for Auto-Balance.  
PRECISION TIG 275  
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INSTALLATION  
A-3  
A-3  
RATED OUTPUT - IEC 60974-1 (K1827-1)  
Duty Cycle-Applications  
40%  
Volts at Rated Amperes  
Amps  
AC/DC Stick / Balance TIG  
31.0  
20.2  
275  
255  
#
Unbalance (70% Penetration ) AC TIG  
60%  
AC/DC Stick / Balance TIG  
29.0  
18.0  
225  
200  
#
Unbalance (70% Penetration ) AC TIG  
100%  
AC/DC Stick / Balance TIG  
28.0  
16.0  
200  
150  
#
Unbalance (70% Penetration ) AC TIG  
ADDITIONAL OUTPUT CAPACITY  
Output Current  
Maximum Open  
Type of Output  
Auxiliary Power  
K1825-1, K1826-1, K1826-2  
Range  
Circuit Voltage  
15Amp Circuit Breaker and NEMA 5-15R Duplex  
Receptacle for up to:  
2Amps DC  
to  
115VAC 8Amp Auxiliary Power Receptacle  
115VAC weld Switched Cooler Receptacle load  
K1834-1  
(STICK AND TIG)  
CC (Constant Current)  
AC/DC (GTAW)  
AC/DC OCV: 75/68  
340Amps AC-DC*  
Stick (SMAW)  
5 Amp Circuit Breaker  
and grounded 220VAC  
Euro(Schuko) receptacle  
RECOMMENDED INPUT WIRE AND FUSE SIZES  
For all Stick, DC TIG, and Balanced AC TIG Welding  
For Unbalanced AC TIG Welding Above 275 Amps:  
255A/40% Duty Cycle, Auto-Balance Penetration with  
out Standard Power Factor Correction Capacitors  
Based on the 1999 U.S. National Electrical Code  
at 275A/40% Duty Cycle with out Standard Power  
Factor Correction Capacitors  
Based on the 1999 U.S. National Electrical Code  
Input  
Type 75°C  
Copper  
Type 75°C  
Copper Wire in  
Conduit AWG  
(IEC) Sizes  
Type 75°C  
Copper Wire in  
Conduit AWG  
(IEC) Sizes  
Type 75°C  
Input  
Voltage /  
phase/  
Ampere  
Fuse  
Input  
Fuse  
Copper  
(Super Lag) Rating  
or Breaker Rating on  
Ground Wire in (Super Lag) Ampere  
Ground Wire in  
Conduit AWG  
(IEC) Sizes  
Rating  
Conduit AWG or Breaker  
40°C (104°F)  
Ambient  
40°C (104°F)  
Ambient  
Size1  
125  
125  
60  
50  
125  
80  
Nameplate  
(IEC) Sizes  
Size1  
150  
150  
70  
60  
150  
90  
Frequency  
2
2
2
2
208/1/60  
230/1/60  
460/1/60  
104  
94  
47  
38  
95  
55  
50  
6 (13.3 mm )  
124  
112  
56  
45  
109  
63  
4 (21.2 mm )  
3 (26.7 mm )  
6 (13.3 mm )  
2
2
2
2
6 (13.3 mm )  
3 (26.7 mm )  
4 (21.2 mm )  
6 (13.3 mm )  
2)  
2)  
2)  
2)  
10 (5.3mm  
8 (8.4 mm  
8 (8.4mm  
8 (8.4 mm  
2)  
2)  
2)  
2)  
575/1/60  
10 (5.3mm  
8 (8.4 mm  
10 (5.3mm  
10 (5.3mm  
2
2
2
2
220-230/1/50/60  
380-400/1/50/60  
415/1/50/60  
6 (13.3 mm )  
4 (21.2 mm )  
4 (21.2 mm )  
6 (13.3 mm )  
2)  
2)  
2)  
2)  
8 (8.4mm  
6 (13.3 mm  
8 (8.4mm  
8 (8.4 mm  
2)  
2)  
2)  
2)  
90  
58  
80  
8 (8.4mm  
6 (13.3 mm  
8 (8.4mm  
8 (8.4 mm  
PHYSICAL DIMENSIONS  
Height  
Width  
Depth  
Weight  
K1826-1, -2  
31.0 in.  
22.0 in.  
26.0 in.  
Approx. 397 lbs.  
180 kgs.  
K1827-1  
787 mm  
559 mm  
660 mm  
K2619-1,-2  
49.7 in.  
28.0 in.  
711 mm  
41.0 in.  
Approx.641 lbs.  
291 kgs.  
K1825-1  
1262 mm  
1041 mm  
TEMPERATURE RANGES  
OPERATING TEMPERATURE RANGE  
STORAGE TEMPERATURE RANGE  
-40°C to +85°C (-40° to +185°F)  
-20°C to +40°C (-04° to +104°F)  
TRANSFORMER INSULATION CLASS 180°C (H)  
1 ALSO CALLED ʻINVERSE TIME" OR "THERMAL/MAGNETIC " CIRCUIT BREAKERS; CIRCUIT BREAKERS WHICH HAVE A DELAY IN TRIPPING ACTION THAT DECREASES AS  
THE MAGNITUDE OF CURRENT INCREASES.  
*
50/60HZ IEC Max. range exceeds 310A.  
PRECISION TIG 275  
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A-4  
A-4  
INSTALLATION  
The machine may topple over if this precaution is not  
followed.  
SAFETY PRECAUTIONS  
Read entire Installation Section before installing  
the Precision Tig 275.  
ENVIRONMENTAL RATING  
WARNING  
Precision TIG 275 power sources carry an IP21S  
Environmental rating. They are rated for use in damp,  
dirty rain-sheltered environments.  
ELECTRIC SHOCK can kill.  
•
•
Only qualified personnel should per-  
form this installation.  
HIGH FREQUENCY INTERFERENCE  
PROTECTION  
Turn the input power OFF  
at the disconnect switch or  
fuse box and discharge input capacitors  
before working inside the equipment.  
The frame of the welder must be grounded. A ground  
•
•
Do not touch electrically hot parts.  
screw marked with the symbol  
is located on the  
Always connect the Precision Tig grounding screw (behind  
the reconnect panel cover located near the back of the left  
case side) to a good electrical earth ground.  
Always connect the Precision Tig to a power supply grounded  
in accordance with the National Electrical Code and all local  
codes.  
input connection panel (Figure A.1) for this purpose.  
See your local and national electrical codes for proper  
grounding methods.  
•
The spark gap oscillator in the high frequency genera-  
tor, being similar to a radio transmitter, can be blamed  
for many radio, TV and electronic equipment interfer-  
ence problems. These problems may be the result of  
radiated interference. Proper grounding methods can  
be reduced or eliminate re-radiated interference.  
SELECT SUITABLE LOCATION  
Place the welder where clean cool air can freely circu-  
late in through the rear louvers and out through the bot-  
tom opening. Dirt, dust or any foreign material that can  
be drawn into the machine should be kept at a mini-  
mum. Failure to observe these precautions can result  
in excessive operating temperatures and nuisance  
trips.  
The Precision TIG 275 has been field tested under rec-  
ommended installation conditions and has been found  
to comply with F.C.C. allowable radiation limits. This  
welder has also been found to comply with NEMA stan-  
dards for high frequency stabilized power sources.  
GRINDING  
Radiated interference can develop in the following four  
ways:  
Do not direct grinding particles towards the welder. An  
abundance of conductive material can cause mainte-  
nance problems.  
* Direct interference radiated from the welder.  
* Direct interference radiated from the welding leads.  
* Direct interference radiated from the feedback into  
the power lines.  
STACKING  
* Interference from re-radiation of “pickup” by  
ungrounded metallic objects.  
The Precision Tig 275 cannot be stacked.  
UNDERCARRIAGE LIFTING AND MOVING  
When the Precision TIG 275 is purchased as a welding  
package, or used with any of the available  
Undercarriage optional accessories, proper installation  
makes the Precision TIG 275 lift bale nonfunctional.  
Do not attempt to lift the power source with an under-  
carriage attached. The undercarriage is designed for  
hand moving only; mechanized movement can lead to  
personal injury and/or damage to the Precision TIG  
275.  
Keeping these contributing factors in mind, installing  
the equipment per the following instructions should  
minimize problems.  
1. Keep the welder power supply lines as short as pos-  
sible and completely enclose them in rigid metallic con-  
duit or equivalent shielding for a minimum distance of  
50 feet (15.2 m). There must be good electrical contact  
between this conduit must be connected to a driven  
ground and the entire length must be continuous.  
2. Keep the work and electrode leads as short as pos-  
sible and as close together as possible. Lengths  
should not exceed 25 feet (7.6m). Tape the leads  
together when practical.  
TILTING  
Each machine must be placed on a secure, level sur-  
face, either directly or on a recommended undercar-  
riage.  
PRECISION TIG 275  
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A-5  
A-5  
INPUT and GROUNDING CONNECTIONS  
INSTALLATION  
3. Be sure the torch and work cable rubber coverings  
are free of cuts and cracks that allow high frequen-  
cy leakage. Cables with high natural rubber content,  
WARNING  
ELECTRIC SHOCK can kill.  
R
such as Lincoln Stable-Arc better resist high fre-  
quency leakage than neoprene and other synthetic  
rubber insulated cables.  
4. Keep the torch in good repair and all connections  
tight to reduce high frequency leakage.  
5. The work terminal must be connected to a ground*  
within ten feet of the welder, using one of the follow-  
ing methods.  
* Turn the input power OFF at the  
disconnect switch or fuse box  
before working on this equip-  
ment.  
___________________________________________  
Be sure the voltage, phase, and frequency of the  
input power is as specified on the rating plate, located  
on the rear of the machine.  
* A metal underground water pipe in direct contact  
with the earth for ten feet or more.  
* A 3/4” (19mm) galvanized pipe or a 5/8” (16mm)  
solid galvanized iron, steel or copper rod driven at  
least eight feet into the ground.  
Fuse the input circuit with the recommended super  
lag fuses or delay type1 circuit breakers. Choose an  
input and grounding wire size according to local or  
national codes or use Section A-2. Using fuses or cir-  
cuit breakers smaller than recommended may result  
in “nuisance” tripping from welder inrush currents  
even if not welding at high currents.  
The ground should be securely made and the ground-  
ing cable should be as short as possible using cable of  
the same size as the work cable, or larger. Grounding  
to the building frame electrical conduit or a long pipe  
system can result in re-radiation, effectively making  
these members radiating antennas. (This is not recom-  
mended.)  
Unbalanced AC TIG welding draws higher input cur-  
rents than those for Stick, DC TIG, or Balanced AC  
TIG welding. The welder is designed for these higher  
input currents. However, where unbalanced AC TIG  
welding above 185 amps is planned, the higher input  
currents require larger input wire sizes and fuses per  
Section A-2:  
6. Keep all access panels and covers securely in  
place.  
7. All electrical conductors within 50 feet (15.2m) of the  
welder should be enclosed in grounded rigid metal-  
lic conduit or equivalent shielding. Flexible helically-  
wrapped metallic conduit is generally not suitable.  
Remove the reconnect panel cover located near the  
back of the left case side to reveal the reconnected  
panel. Welder supply line entry provision is in the  
case rear panel. Entry is through a 1.75 inch (44mm)  
diameter hole in the case back. Appropriate supply  
line strain relief clamp is provided by installer. (See  
Figure A.1)  
8. When the welder is enclosed in a metal building,  
several earth driven electrical grounds (as in 5  
above) around the periphery of the building are rec-  
ommended.  
All connections should be made in accordance  
Failure to observe these recommended installation  
procedures can cause radio or TV interference prob-  
lems and result in unsatisfactory welding performance  
resulting from lost high frequency power.  
FIGURE A.1  
CONNECT INPUT  
POWER LEADS  
CONNECT INPUT  
CONNECT INPUT  
VOLTAGE LEVEL  
GROUND LEAD  
with all local codes and national electrical codes.  
Installation by a qualified electrician is recom-  
mended.  
PRECISION TIG 275  
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A-6  
A-6  
INSTALLATION  
1. Connect the terminal marked  
nect panel) to an earth ground.  
(below the recon-  
Recommended Cable Sizes for Combined Lengths of  
o
Copper Work and Electrode Cables using 75 C Wire:  
Machine Rating  
0 to 100 Ft.  
101 to 200 Ft  
201 to 250 Ft  
2. Connect the input leads to terminals marked L1 (U)  
and L2 (V) on the reconnect panel. Use a single  
phase line or one phase of a two or three phase line.  
2
2
2
275A/40%  
#1 (42.4 mm ) 1/0 (53.5 mm ) 2/0 (67.4 mm )  
WORK CABLE CONNECTION  
3. On multiple input voltage welders, be sure the  
reconnect panel is connected for the voltage being  
supplied to the welder.  
A 15ʼ (2/0) weld cable with clamp is available (K2150-1), or  
included with the Precision TIG Welding Package model.  
Otherwise, it is user provided.  
CAUTION  
With power source off, connect a separate work cable  
to the 1/2-13 threaded "WORK" stud of the welder, and  
secure a tight connection with the flange nut provided.  
The work cable should be routed through the cable  
strain relief hole provided in the base directly below the  
welding output terminal.  
Failure to follow these instructions can cause  
immediate failure of components within the welder.  
------------------------------------------------------------------------  
Welders are shipped connected for the highest input  
voltage as listed on the rating plate. To change this  
connection, designations on the reconnect panel LOW,  
MID, and HIGH correspond to the name plated input  
voltages of a triple voltage welder. Dual voltage  
welders use only LOW and HIGH.  
Note: If the Precision TIG is equipped with an Under-  
Cooler or Under-Storage unit, the coiled work cable  
and clamp, or excess work cable length, may be con-  
veniently stored in the drawer while remaining con-  
nected.  
STICK ELECTRODE CABLE CONNECTION  
EXAMPLE: On a 208/230/460 volt welder, LOW is  
208V, MID is 230V, and HIGH is 460V.  
NOTE: Export model has a voltage range for LOW and  
MID connections: LOW is 220-230V, MID is 280-  
400V and high is 415V.  
If manual stick welding is desired, with power source  
off, connect a stick electrode cable to the 1/2-13  
threaded "STICK Electrode" stud of the welder, and  
secure a tight connection with the flange nut provided.  
The electrode cable should be routed through the  
cable strain relief hole provided in the base directly  
below the welding output terminal.  
Reconnect the jumper strap to the terminal stud corre-  
sponding to the input voltage level used. Make sure all  
connections are tight.  
WARNING  
WARNING  
DISCONNECT STICK ELECTRODE WELDING  
CABLE WHEN TIG WELDING.  
OUTPUT CABLES, CONNECTIONS AND  
LIMITATIONS  
EVEN THOUGH HI-FREQ IS NOT APPLIED TO THE  
PRECISION TIG STICK TERMINAL, IT WILL BE  
ELECTRICALLY "HOT" TO WORK WHEN TIG  
WELDING.  
• To avoid being startled by a high frequency  
shock, keep the TIG torch and cables in good  
condition  
• Turn the power switch of the power source OFF  
before installing adapters on cable or when con-  
necting or disconnecting adapter plugs to power  
source.  
------------------------------------------------------------------------  
-----------------------------------------------------------------------  
Refer to Figure A.2 for the location of the WORK and  
STICK terminals, as well as the TIG Torch connection  
panel.  
PRECISION TIG 275  
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A-7  
A-7  
INSTALLATION  
FIGURE A.2  
TIG TORCH  
CONNECTION  
PANEL  
REMOTE  
CONTROL  
RECEPTACLE  
STICK  
WORK  
WORK  
STICK  
ELECTRODE  
STUD  
STUD  
(Shown without hinged stud cover)  
FIGURE A  
CABLE  
STRAIN  
RELIEF HOLES  
TIG TORCH CONNECTION  
CYLINDER could explode  
if damaged.  
The Precision TIG torch connection box, located on the  
right side of the machine, provides all the input and  
output connections for the installation of both air-  
cooled and water-cooled TIG torches with fittings con-  
forming to Compressed Gas Association (CGA) stan-  
dards:  
• Keep cylinder upright and  
chained to a support.  
• Keep cylinder away from areas  
where it could be damaged.  
• Never allow the torch to touch the cylinder.  
• Keep cylinder away from live electrical cir-  
cuits.  
Note: The Precision TIG provides an insulated Torch  
Reel and Holster for handy and safe storage of con-  
nected torch when not welding, and excess torch cable  
length while welding.  
• Maximum inlet pressure 150 psi.  
-----------------------------------------------------------------  
The Precision TIG machines do not have Hi-Freq.  
available at the Stick electrode stud, therefore stud  
connection adapters (such as LECO. S19257-series)  
cannot be used for torch connection.  
WARNING  
Combination connectors (Power/Water and  
Power/Gas) are electrically "hot" while welding in  
STICK or TIG modes.  
Single-piece cable air-cooled torches with a 3/8-24 RH  
connector fitting (such as the Magnum PTA-9/-17, or LA-  
9/-17) require the provided S20403-4 Torch Connector,  
while those with a 7/8-14 RH connector fitting (such as  
the Magnum PTA-26, or LA-26) require the available  
K2166-1 Torch Connector. (See Figure A.3)  
If using an Air-Cooled Torch be sure coolant is  
shut off and/or Cooler is unplugged from the  
Precision TIG Water Cooler Receptacle on the  
torch side of the upper case back.  
Two-piece cable air-cooled torches (such as PTA-, or LA-  
torches) can be used with the available 1/2” Stud  
Connector (S20403-3) with with a 7/8-14 LH male fitting.  
Observe the safety precautions necessary for han-  
dling and using compressed gas containers.  
Contact your supplier for specifics.  
Magnum PTW-18/-20 (or LW-) water-cooled Torches  
require no adapter for Precision TIG connection.  
PRECISION TIG 275  
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A-8  
A-8  
INSTALLATION  
FIGURE A.3  
For Gas Supply hose  
with 5/8-18RH male  
(Provided with Weld  
Package model)  
For Coolant Supply  
Hoses  
with 5/8-18LH male  
(Provided with Weld  
Package model  
or  
Under-Cooler Cart)  
AUXILIARY POWER CONNECTIONS  
Note: When the breaker trips not only will the auxil-  
iary and cooler power be interrupted, but so will the  
power to the shielding gas solenoid and machine  
cooling fan.  
The Precision TIG machines provide a standard NEMA  
5-15R duplex receptacle, located on the upper case  
back on the torch side of the machine:  
The Precision TIG Export models also provide a  
grounded 220 VAC Euro type Schuko receptacle and a  
5 amp circuit breaker, located on the upper case back  
on the reconnect side of the machine, intended for use  
with a 220 VAC water cooler.  
• The bottom outlet of this duplex receptacle provides  
switched 115VAC power for the Under-Cooler, or  
Water Solenoid accessory. This Cooler receptacle  
turns on when the arc starts and remains on for about  
8 minutes after the arc goes out (with the Fan-As-  
Needed machine cooling fan, see Maintenance  
Section), so the Coolerʼs fan and water pump will not  
run continuously in idle, but will run while welding.  
REMOTE CONTROL (If Used)  
• The top outlet of this duplex receptacle provides at  
least 8 amps at 115VAC, whenever the Precision TIG  
Power switch is ON. This auxiliary circuit is intended  
for running 115VAC accessories or small power tools.  
Note: Some types of equipment, especially pumps  
and large motors, have starting currents which are  
significantly higher than their running current. These  
higher starting currents may cause the circuit breaker  
to open. (See next paragraph)  
The Foot Amptrol (included with the Precision TIG  
Welding Package), or other Remote accessory, is  
installed by routing the plug of its control cable up  
through the left cable strain relief hole provided in the  
base (see Figure A.2), then connecting the 6-pin plug  
to the mating Remote receptacle behind the stud panel  
cover. (See Operation Section B-2 for mating plug  
wiring.)  
Note: If the Precision TIG is equipped with an Under-  
Cooler or Under-Storage unit, the Foot Pedal (or other  
remote control accessory) and coiled control cable, or  
excess cable length, may be conveniently stored in the  
drawer while remaining connected.  
• Both the receptacle circuits are protected from shorts  
and overloads by a 15 amp circuit breaker, located  
above the receptacle. if the breaker trips its button  
pops out exposing a red ring. When the circuit break-  
er cools the button can be reset by pressing it back  
in.  
PRECISION TIG 275  
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A-9  
A-9  
INSTALLATION  
ROBOTIC INTERFACE CONNECTION  
Robotic interface can be made at the Remote  
Receptacle (See Operation Section). The machine is  
shipped with the remote receptacle circuit internally  
connected to receptacle J5 of the Control board for  
standard Amptrol operation. In order to enable the  
remote receptacle for robotic interface its connection  
plug must be moved from J5 to J5A on the Control  
board. (Refer to the machine Wiring Diagram.)  
The robotic interface functions with the Precision TIG  
set to either TIG or STICK mode, but must be in  
REMOTE switch position for the Preset Control inter-  
face to function. When in the REMOTE position with  
robotic interface neither the MAXIMUM OUTPUT nor  
the MINIMUM OUTPUT panel controls limit the inter-  
face control setting over the rated output range of the  
machine.  
The diagram in Figure A.4 below shows the remote  
receptacle plug connections and signals for robotic  
interface:  
FIGURE A.4  
REMOTE RECEPTACLE  
(Front View)  
For 18-12P Plug  
(LECO S12020-27)  
PRESET CONTROL  
INPUT FROM ROBOT  
(0 -10Vdc = Rated Output Range)  
+
C
Note: The Interface connection  
cable may pick up noise  
+VCC = 70Vdc max.  
B
A
D
E
ARC START  
INPUT FROM ROBOT  
(18Vac,10ma switch)  
*
F
interference. Additional  
bypass/filtering circuits may be  
needed for the external circuits.  
R = VCC / 5ma  
ARC ESTABLISHED  
OUTPUT TO ROBOT  
(High = Not Welding)  
(Low = Welding)  
5ma  
Robotic  
Common  
*
Precision TIG Control Common.  
PRECISION TIG 275  
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A-10  
A-10  
NOTES  
PRECISION TIG 275  
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TABLE OF CONTENTS  
B-1  
B-1  
- OPERATION SECTION -  
Operation...............................................................................................................................Section B  
Safety Precautions......................................................................................................................B-2  
Product Description.....................................................................................................................B-2  
Recommended Process and Equipment ....................................................................................B-3  
Controls and Settings..................................................................................................................B-4  
Welding Operation................................................................................................................B-5/B-8  
Internal Set Up Controls..............................................................................................................B-9  
2 Step Trigger Modes................................................................................................................B-10  
4 Step Trigger Modes................................................................................................................B-11  
TIG Weld Cycle Chart...............................................................................................................B-12  
Set Up for TIG Amptrol Welding................................................................................................B-13  
Making a TIG Weld with an Amptrol .........................................................................................B-14  
Recommended Electrode Amperage Ranges...........................................................................B-14  
PRECISION TIG 275  
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B-2  
B-2  
OPERATION  
SAFETY PRECAUTIONS  
PRODUCT DESCRIPTION  
Read and understand this entire section before operat-  
The Precision TIG 275 is part of a new family of indus-  
trial arc welding power sources providing constant cur-  
rent, single range square wave AC/DC TIG (GTAW)  
ing the machine.  
TM  
WARNING  
with new patented (pending) Micro-Start Technology,  
Presettable Min. and Max. Output controls, and built-in  
high frequency stabilization for continuous AC TIG and  
DC TIG starting. It also has AC/DC Stick (SMAW)  
capability, with adjustable Arc Force availability. A TIG  
Pulse Panel. Power Factor Capacitors and a Water  
Solenoid are available as field installed optional kits.  
Also, a new Undercarriage (with double gas bottle  
rack) is available for field installation, as well as a new  
Under-Cooler Cart, which is also included in an avail-  
able efficiently integrated entire TIG Welding Package  
with convenient built-in storage provisions for welding  
equipment and components.  
ELECTRIC SHOCK CAN KILL.  
*Only qualified personnel should per-  
form the installation.  
* Turn the input power OFF at the dis-  
connect switch or fuse box.  
* Do not touch electrically live parts or  
electrode with skin or wet clothing.  
* Insulate yourself from work and  
ground.  
* Always dry insulating gloves.  
* Read and follow “Electric Shock  
Warnings” in the Safety section if  
welding must be performed under  
electrically hazardous conditions  
such as welding in wet areas or on  
or in the workpiece.  
The Precision TIG 275 includes advanced features  
such as a Digital Meter, Presettable control, Auto  
TM  
Balance , Fan As Needed (F.A.N.) fixed Preflow, vari-  
able Postflow shielding gas and Timers. In addition, 2-  
Step/4-Step and Pulse TIG operation with adjustable  
Downslope Time control are included with an available  
field installed kit. It also features a Stick stud panel and  
a universal TIG torch connection box for simultaneous,  
but separated, electrode outputs.  
......................................................................................  
FUMES AND GASES  
can be dangerous.  
* Keep your head out of fumes.  
*Use ventilation or exhaust to  
remove fumes from breathing  
zone.  
The Precision TIG 275 has enhanced Features which  
includes the following:  
......................................................................................  
WELDING SPARKS  
can cause fire and explosion  
* Keep flammable material away.  
* Do not weld on containers that  
have held combustibles.  
• MicroStart™ Codes Below 11000  
• MicroStart™ II Codes Above 11000  
• Auto-Balance optimized  
• Menu button added  
• Spot On selection added  
PIPE THAWING  
......................................................................................  
ARC RAYS  
The Precision TIG 275 is not recommended for pipe  
thawing.  
can burn.  
* Wear eye, ear and body protec-  
tion.  
Duty Cycle  
The duty cycle is based upon a 10-minute time period;  
i.e., for 40% duty cycle, it is 4 minutes welding and 6  
minutes idling. If the rated duty cycle is significantly  
exceeded, the thermostatic protection will shut off the  
output until the machine cools to a normal operating  
temperature. (Refer to Specification Section A-1)  
......................................................................................  
Observe additional Safety Guidelines detailed in  
the beginning of this manual.  
PRECISION TIG 275  
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B-3  
B-3  
OPERATION  
RECOMMENDED PROCESSES AND  
EQUIPMENT  
EQUIPMENT LIMITATIONS  
The Precision TIG machines are protected from over-  
loads beyond the electrical ratings and duty cycles, per  
the Specifications Section A-2, A-3, with Thermostat  
protection of the primary and secondary transformer  
coils.  
RECOMMENDED PROCESSES  
The Precision TIG 275 is recommended for the TIG  
(GTAW) and Stick (SMAW) welding processes within  
its output capacity range of 2 amps DC, or 5 amps AC,  
to 340 amps AC/DC. It is compatible with most  
Magnum TIG accessories (refer to Equipment  
Limitations), as well as many industry standard items,  
such as TIG torches, hoses, and water coolers.  
The Precision TIG machines do not have Hi-Freq.  
available at the Stick electrode stud, therefore stud  
connection adapters (such as LECO. S19257-series)  
cannot be used for torch connection.  
PROCESS LIMITATIONS  
Precision TIG machines are not recommended for arc  
gouging due to it's limited output capacity, and are also  
not recommended for pipe thawing.  
RECOMMENDED EQUIPMENT/INTERFACE FOR CODES ABOVE 11000  
TIG (water cooled)  
TIG (air cooled)  
Machine:  
PT275 Welding Package (K2618-1)  
User provided  
PT275(K2619-1,-2)  
User provided  
Input Cable/Clamp:  
Gas Reg./Hose:  
Magnum Torch:  
Magnum Parts:  
Work Clamp/Lead:  
Foot Amptrol:  
(included)  
LE/Harris 3100211  
PTA9 or PTA17  
(PTW20 included)  
(KP510 and K918-2 included)  
(15 ft. included)  
KP507 or KP508  
K2150-1 Work Lead Assembly  
K870  
(K870 included)  
RECOMMENDED EQUIPMENT/INTERFACE FOR CODES BELOW 11000  
TIG (water cooled)  
PT275 Welding Package (K1825-1)  
User provided  
TIG (air cooled)  
Machine:  
PT275(K1826-1, -2, K1827-1)  
User provided  
Input Cable/Clamp:  
Gas Reg./Hose:  
Magnum Torch:  
Magnum Parts:  
Work Clamp/Lead:  
Foot Amptrol:  
(included)  
LE/Harris 3100211  
PTA9 or PTA17  
(PTW20 included)  
(KP510 and K918-2 included)  
(15 ft. included)  
KP507 or KP508  
K2150-1 Work Lead Assembly  
K870 or K870-1  
(K870 included)  
PRECISION TIG 275  
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B-4  
B-4  
OPERATION  
CONTROLS AND SETTINGS  
The Front Control Panel contains the knobs and switches necessary for adjusting the operation of the Precision  
TIG 275, with function indicator lights and an electronic display for volts and amps. The components are  
described below:  
FIGURE B.1 - CONTROL PANEL  
1. POWER SWITCH  
9
5
8
6
2. POLARITY SWITCH  
7
7a  
3. MODE SWITCH  
4. AC BALANCE CONTROL  
5. LOCAL/REMOTE CURRENT CONTROL  
SWITCH  
6. MAXIMUM OUTPUT CONTROL  
7. MINIMUM OUTPUT CONTROL AND  
DISPLAY SWITCH  
7.a MENU BUTTON AND DISPLAY  
SWITCH FOR CODES ABOVE 11000  
8. DIGITAL METER AND DISPLAY  
SWITCH  
9
3
4
9. POSTFLOW TIME  
10. THERMAL SHUTDOWN LIGHT  
11. REMOTE RECEPTACLE  
12. TRIGGER SWITCH  
10  
13. PULSE MODE SWITCH  
14. PULSE FREQUENCY CONTROL  
15. PULSE % ON TIME CONTROL  
16. PULSE BACKGROUND CURRENT  
CONTROL  
13 14  
12  
16  
17  
15  
17. DOWNSLOPE TIME  
1
2
11  
1. POWER SWITCH - Input line switch turns input  
power ON or OFF, as indicated by the on or off sta-  
tus of the front panel displays.  
• The CC Stick mode may be used for general pur-  
pose stick welding (SMAW ) within the capacity of  
the machine. The capacity is too limited for air car-  
bon arc gouging (CAC-A).  
2. POLARITY SWITCH – The 3-position rotary power  
switch has detente positions for DC-, AC and DC+  
selections for the Electrode output welding polarity.  
• In this mode; the output terminals are activated  
electrically HOT, gas flow is not activated and HOT  
START and ARC FORCE levels are fixed, or  
Advanced Panel selectable (See Section B-7 ), with  
no front panel adjustment.  
3. MODE SWITCH – The mode switch allows vertical-  
ly positioned selection of the two machine welding  
modes. The selected mode is indicated by a lit col-  
ored panel light which permits viewing the machine  
setting from a distance:  
3.b TIG mode (Bottom position) – No panel light.  
• When the Polarity Switch is set to AC, the TIG  
mode provides continuous high frequency to stabi-  
lize the arc for AC TIG welding.  
3.a STICK mode (Top position) –Red panel light  
WARNING  
• Hi-Freq. turns on after preflow time with the arc  
start switch closure, and turns off when the arc  
goes out* after the arc start switch opens.  
ELECTRIC SHOCK can kill.  
• When the Power Source is ON in  
STICK mode the Electrode circuits of  
both the Stick and TIG torch cables  
* Arc voltage and current are sensed to determine if  
the arc is established or out.  
are electrically HOT to Work.  
------------------------------------------------------------------------  
PRECISION TIG 275  
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B-5  
B-5  
OPERATION  
• When the Polarity Switch is set to DC (- or +), the  
TIG mode provides high frequency only for starting.  
• With the Current Control switch to REMOTE posi-  
tion, this knob sets the maximum welding level that  
the Peak output can be set with the remote Amptrol.  
• Hi-Freq. turns on after pre-flow time with the arc  
start switch closure, and turns off when the arc is  
established*  
TM  
• The new MicroStart Technology minimum current  
circuit provides for low end welding (down to 2  
amps) previously unobtainable on an SCR platform  
TIG machine.  
• DC+ polarity can also be used for ”balling” of the  
tungsten for AC TIG welding.  
7. MINIMUM OUTPUT CONTROL AND DISPLAY SWITCH–  
A smaller knob is used to preset the minimum cur-  
rent level only for TIG mode. Pressing the Display  
(momentary) switch toggle left to Minimum Set posi-  
tion displays the Minimum control level setting on the  
Digital meter. (See Item 8)  
4. AC BALANCE CONTROL – The potentiometer  
control permits AC wave balance adjustment from  
Max. Penetration (~85% negative wave) with the  
control at Max. full CW position, to Max. Cleaning  
(~65% positive wave) with the control set near min-  
imum CCW position.  
• This knob sets the Start output level. When the arc  
lights (using a new built-in TIG start pulse) this level  
upslopes quickly (0.5 sec.w/ Advanced Panel, zero  
w/o) and smoothly to the weld output level. The set-  
ting range for this Start control is the 2 amp mini-  
mum range of the machine up to about 50 amps, but  
no more than the level set by the Maximum Output  
control knob (See Item 6), but otherwise is indepen-  
dent of the Maximum setting.  
• Full minimum CCW position is the Auto Balance  
position which is indicated by the Green panel light  
turning on. This feature automatically provides the  
proper amount of cleaning and penetration for nor-  
mal AC TIG welding  
• The mid position is the Balanced position (~50%  
positive and negative waves).  
• The Balance control is only functional if the machine  
is set to AC polarity and TIG mode.  
• This setting also serves as the Crater-fill level, but  
with a Precision TIG Advanced Panel it can be  
selected (see Section B-7) to be either the Minimum  
Output control setting (same as Start setting) as  
shipped, or the minimum rating of the machine (2  
amps).  
5. LOCAL/REMOTE CURRENT CONTROL SWITCH – A  
2-position switch selects how the welding output is  
controlled for both Stick and TIG Modes:  
• LOCAL (Top position) selects output control only by  
the machine panel Output Control. (See Item 6)  
• The Remote Amptrol range of control is between  
this Minimum setting and the Maximum Output con-  
trol knob setting, so these knobs can set the resolu-  
tion of the Amptrol. Also, the Minimum setting  
serves as both the minimum Amptrol start level  
when the arc start switch is closed, as well as the  
minimum Amptrol crater-fill level before the arc start  
switch is opened to help prevent premature arc out  
and Hi-Freq re-initiation.  
• REMOTE (Bottom position) selects output control to  
also be by an Amptrol (See Item 6), or other remote  
(10K pot) control connected to the Remote recepta-  
cle (See Item 11) This switch selection is indicated  
by the Green panel light turning on.  
In either position the arc start switch functions when  
connected to the Remote receptacle (See Item 11).  
.
• In STICK mode the Start control is not functional  
since Hot Start level is fixed, or internal Advanced  
Panel adjustable (see Section B-7). Pressing the  
Display (momentary) switch toggle left to Minimum  
Output position displays minimum amps rating of  
the machine.  
6. MAXIMUM OUTPUT CONTROL – The large knob  
is used to set the output welding current over the  
rated output range of the machine.  
• With the Current Control switch to LOCAL position,  
this knob sets the welding output level.  
PRECISION TIG 275  
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B-6  
B-6  
OPERATION FOR CODES ABOVE 11000 ONLY  
a
7 MENU BUTTON AND DISPLAY SWITCH (Codes  
above 11000) – Pressing and holding the (Menu)  
Button for about 5 seconds enters the menu display  
which allows:  
TIG Mode Menu (with Advanced Control Panel installed):  
Setting: Description:  
Selection 4: HS (TIG Hot Start % of output setting)  
0 *  
1
+0%  
(Only setting for SS0, above.)  
+10%  
+20%  
+30%  
+40%  
+50%  
+60%  
+70%  
+80%  
+90%  
2
• Selection of up to seven programmable parameters  
(Preflow, Upslope, Hot Start, Arc Force, etc.) on the  
digital meter is achieved by momentarily pressing  
and releasing the MENU button to step through the  
parameters.  
3
4
5
6
7
8
• Setting of the desired level, displayed on the digital  
meter for the selected parameter, is done by press-  
ing the DISPLAY (momentary) switch toggle to the  
right to increase the level setting, or to the left to  
decrease it.  
9
Selection 5: UP (Upslope Time)  
0
1*  
2
None  
(Only setting for SS1 & SS2, above.)  
0.5 sec.  
1.0 sec.  
1.5 sec.  
2.0 sec.  
2.5 sec.  
3
4
5
DIGITAL DISPLAY  
* Default Factory Setting. (Indicated by "blinking" decimal point.)  
(SET)  
DISPLAY  
(SELECT)  
DISPLAY  
◊
STICK Mode Menu (with Advanced Control Panel installed ):  
Setting: Description:  
Selection 6: HS (Stick Hot Start % added to output setting)  
0
1
+0%  
+10%  
+20%  
+30%  
+40%  
+50%  
+60%  
+70%  
+80%  
+90%  
2
TIG Mode Menu  
3
Setting:  
4
Description:  
Selection 1:  
5 *  
6
HF (High Freq.)  
0
Scratch start TIG (No Hi-Freq.)  
Normal Hi-Freq. start and weld  
Lift TIG (Touch start w/o Hi-Freq.)  
PF (Preflow time)  
1 *  
7
2
8
Selection 2:  
9
0
Selection 7: AF (Stick Arc Force % added to output setting)  
No Preflow  
1
0
1 *  
2
+0%  
("Softer" arc)  
0.1 sec.  
2 *  
+10%  
+20%  
+30%  
+40%  
+50%  
+60%  
+70%  
+80%  
+90%  
0.5 sec.  
3
1.0 sec.  
4
3
1.5 sec.  
5
4
2.0 sec.  
Selection 3:  
5
SS (MicroStart™ Start Pulse)  
No AC pulse/Low DC pulse (soft start)  
High AC/DC pulse (forceful start)  
HS setting (see below) for each pulse when Pulse  
mode welding anodized aluminum.  
0 *  
1
6
7
2
8
∆
9
("Crisper" arc)  
* Default Factory Setting. (Indicated by "blinking" decimal point.)  
* Default Factory Setting. (Indicated by "blinking" decimal point.)  
◊
If no Advanced Control Panel the Stick menu  
∆ Only selectable with Advanced Control Panel installed.  
displays “- - -“.  
• Any of the following actions will exit the menu display:  
1. Pressing and holding the (Menu) Button again for about 5 seconds.  
2. Allowing the menu display to be unchanged for about 15 seconds.  
3. Closing the arc start switch (TIG Mode) or starting the arc (Stick Mode).  
Note: In Stick Mode the machine output will remain on while in menu display.  
• Re-entering the menu displays the last parameter and setting that was displayed when the menu was  
exited.  
• All settings may be reset to the Factory Default Settings (above) by holding the (Menu) button pressed while  
turning on the machineʼs Power switch. The display will show “rES” to indicate the defaults are reset.  
PRECISION TIG 275  
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B-7  
B-7  
OPERATION  
8. DIGITAL METER AND DISPLAY SWITCH– A 3-  
digit LED meter is used to monitor the preset and  
actual welding procedure based on the Display  
(momentary) switch position:  
• When the Current Control Switch is in either LOCAL  
or REMOTE positions the arc start switch functions  
when connected to the Remote receptacle.  
FIGURE B.2  
• Before welding with Display switch in center (nor-  
mal) position, the digital meter displays the preset  
welding amps set by Maximum Output control knob  
(See Item 6). If in Stick mode using REMOTE (See  
Item 5.), the digital meter displays the preset weld-  
ing amps set by the Remote control. (See Item 11)  
• While welding with Display switch in center (normal)  
position, the digital meter displays the actual weld-  
ing amps with one amp resolution (XXX) and accu-  
racy within 4%+/-2A of reading.  
REMOTE RECEPTACLE*  
(Front View)  
ARC START  
SWITCH  
REMOTE OUTPUT  
CONTROL  
C
F
Max  
B
A
D
E
10K ohm  
Min  
*For 18-12P Plug  
(LECO S12020-27)  
• At any time in TIG mode, pressing the Display  
switch to left causes the digital meter displays the  
amps preset by the Minimum Output control knob  
(See Item 7).  
ADVANCED PANEL CONTROLS  
The following controls are included only if the Precision  
TIG 275 has the Advanced Control Panel (K1829-1)  
option installed: (Refer to Figure B.3 Tig Weld Cycle  
Chart for graphic illustration of these TIG welding func-  
tions.)  
• At any time in Stick mode, pressing the Display  
switch to left causes the digital meter to display the  
minimum amps rating of the machine (See Item 7).  
• In either mode, while pressing the Display switch  
right to Volts position, the digital meter displays  
actual output volts. Volts is displayed with 0.1 volt  
resolution (XX.X) and accuracy within 3%+/-1V of  
reading.  
12. TRIGGER SWITCH – This 2-position switch  
selects how the arc start switch ( connected to the  
above Remote receptacle) functions; in 2-Step or  
4-Step mode:  
9. POSTFLOW TIME – This knob is used to set the  
TIG mode shielding gas postflow time over the  
range of about 2 to 60 seconds after the arc is shut  
off. The postflow on time status is indicated by the  
Green panel light.  
CAUTION  
• DO NOT USE 4-STEP IF USING AN AMPTROL  
REMOTE.  
• Neither the arc start switch nor the output con-  
trol in the amptrol will function normally to shut  
off or control the output. ONLY USE 2-STEP.  
------------------------------------------------------------------------  
• In 2-Step position the arc start switch functions the  
same as without the Advanced Panel:  
• Gas preflow time for TIG mode is fixed at 0.5 sec-  
onds, with no panel control.  
• Both time ranges are x2 extendable, if needed, by  
internal control box selection. (See Section B-7)  
1. Closing switch starts preflow, then a fixed  
(0.5 sec.) ramp time from Minimum (Start)  
setting level (See Item 7) to Weld setting.  
10. THERMAL SHUTDOWN LIGHT – This yellow LED  
panel light turns on if the machine output is shut-  
down because internal overheating has occurred,  
and turns off when the thermostat resets.  
2. Opening switch initiates Downslope ramp  
time setting (See Item 17), from Weld set-  
ting to Crater-fill level (See Item 7), which  
then stops the arc and initiates Postflow  
time (See Item 9).  
11. REMOTE RECEPTACLE – A 6-socket receptacle  
is provided for the connection of an Amptrol, or  
other remote control: (See Figure B.2)  
• When the Current Control Switch (See Item 5) is in  
the REMOTE position, the Amptrol or other remote  
(10K pot) connected to the Remote receptacle con-  
trols the TIG or Stick mode output within the range  
preset by the Maximum and Minimum Output con-  
trols. (See Item 6, 7, and 8 for meter display.)  
Note: See Figure B.3 for 2-Step operation during  
Downslope with Restart feature selected to be dis-  
abled, instead of enabled (as shipped).  
PRECISION TIG 275  
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B-8  
B-8  
OPERATION  
• The 4-Step position allows welding without contin-  
14. PULSE FREQUENCY CONTROL – This knob is  
used to set the Pulse Frequency over the peak  
pulse range of about 0.1 pps to 20 pps. (One pulse  
cycle time = 1/pps = 10 to .05 sec. range.)  
uously holding the start switch trigger. The arc start  
switch functions in the following manner:  
1. Closing the switch starts preflow, then arc  
starts at Minimum (Start) setting level (See  
Item 7). If the trigger is maintained closed  
after preflow time the output remains at the  
Start level until it is released.  
15. PULSE % ON TIME CONTROL (PULSE% ON /  
SPOT TIME CONTROL for codes above 11000) •  
• % ON TIME controls the duration of the peak cur-  
rent as a percentage (5% to 95%) of one pulse  
cycle. The balance of the cycle time will be at the  
Background Current setting. (See Item 16)  
2. Opening the switch initiates fixed (0.5 sec.)  
ramp time from Start setting level to Weld  
setting.  
• SPOT TIME sets the duration of the SPOT pulse  
(0.5 to 5.0seconds on the red scale).  
3. Reclosing the switch initiates Downslope  
ramp time setting (See item 17) from Weld  
setting down to the Crater-fill level (See  
Item 7) of the machine.  
16. PULSE BACKGROUND CURRENT CONTROL –  
This knob controls the level of the Background  
Current as a percentage (MIN.-100%) of the Peak  
(REMOTE and/or LOCAL) output level (See Item  
6) down to the Minimum Output setting (See Item  
7).  
4. Reopening the switch after Downslope time  
holds Crater-fill level until it times out, then  
stops the arc and initiates the Postflow Time  
(See Item 9). Reopening switch during  
Downslope time immediately stops the arc  
and initiates the Postflow.  
17. DOWNSLOPE TIME– This knob is used to set the  
time, over the range of zero to about 10 seconds,  
to ramp down from weld setting to Crater-fill level  
(See Item 7).  
Note: See Figure B.4 for 4-Step operation during  
Downslope with Restart feature selected to be  
enabled, instead of disabled (as shipped).  
• If the arc goes out after the Downslope time is initi-  
ated, the Downslope time is interrupted and the  
Postflow time is initiated. This prevents Hi-Freq re-  
initiation during ramp down crater fill  
13.PULSE MODE SWITCH (PULSE / SPOT MODE  
SWITCH for codes above 11000) – Turns on the  
Pulse Mode as indicated by the Green panel light  
turning on.  
• When using an Amptrol remote control, where the  
downslope is controlled by the operator down to the  
crater-fill level, the Downslope time should be set to  
zero so as not to have the Downslope time delay  
when the arc start switch is opened.  
• PULSE ON position provides a Peak current level  
set by REMOTE and/or LOCAL control of the output  
current (See Item5), for a time determined by the  
Pulse Frequency Control setting (See Item 14) and  
the % ON Time (See Item 15). The balance of the  
cycle time is at the Background Current level (See  
Item 16).  
• Pulsing begins after upslope when the output cur-  
rent rises above the Background Current level and  
ends when the output current drops below this level  
.
• SPOT ON position provides the peak current level  
set by the Maximum Output Control for a time deter-  
mined by the SPOT TIME control. A red panel light  
is ON to indicate SPOT mode.  
PRECISION TIG 275  
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B-9  
B-9  
OPERATION  
• Switch #7 Arc Force Level(codes below 11000)–  
Prevents "stubbing" of the electrode by providing  
extra output current if the arc voltage drops below  
the level required to sustain the welding arc. High  
(+65%) and Low (+12%) factory set levels are  
selectable which are good for most stick welding  
applications.  
INTERNAL SET UP CONTROLS  
Precision TIG 275 models which have an Advanced  
Panel (K1829-1) option installed* have the following  
additional control features which are set up using the  
DIP Switch (S1) provided on the internal panel of this  
option.  
ON – Higher for a "crisper" arc, often desired for 6010  
type electrodes.  
Access to this internal panel is obtained by removing  
the two screws securing the top corners of the  
Precision TIG front control panel and swinging the con-  
trol panel down to reveal the panel mounted on the sur-  
face of the Precision TIG Control board:  
OFF – Lower Arc Force (as shipped) for a "softer" arc  
with 7018 or general type electrodes.  
• Switch #6 & #7 - Not functional on codes  
above 11000 - See item 7a for  
adjustment of Hot Start and  
Arc Force  
CAUTION  
• THE CONTROL BOARDS CONTAIN STATIC SEN-  
SITIVE COMPONENTS  
• Switch #8 - (NOT CURRENTLY FUNCTIONAL)  
• To avoid possible damage to these components  
be sure to ground yourself by touching the  
machineʼs sheet metal while handling or making  
settings on the internal control box components.  
------------------------------------------------------------------------  
PRECISION TIG ADVANCED PANEL  
TIG WELDING FEATURES  
The following DIP switch feature selections function  
only when the Precision TIG is set to TIG mode (See  
Item 3):  
(Internal Panel)  
• Switch #1 Preflow/Postflow Time Extension*  
^ ON  
1 2 3 4 5 6 7  
(See Item 9)  
DIP SWITCH (S1)  
ON – Doubles the time ranges.  
OFF – Standard time ranges (as shipped).  
• Switch #2 2-Step Trigger Restart Feature (See  
Figure B.3)  
S
F
ON – Restart Enabled (as shipped).  
OFF – Restart Disabled.  
ON  
• Switch #3 4-Step Trigger Restart Feature (See  
1
2
3
4
5
6
7
8
Figure B.4)  
OFF  
DIP SWITCH POSITIONS (FACTORY SETTINGS)  
ON – Restart Enabled.  
OFF – Restart Disabled (as shipped)  
STICK WELDING FEATURES  
• Switch #4 (NOT CURRENTLY FUNCTIONAL)  
The following DIP switch feature selections function  
only when the Precision TIG is set to Stick mode. (See  
Item 3):  
• Switch #5 Crater-Fill Level (See Item 7)  
ON - Level is minimum rating of the machine (2A)  
OFF – Level (as shipped) is Minimum Output setting  
(same as Start level).  
• Switch #6 Hot Start Level (codes below 11000) –  
Provides an extra output "boost" pulse at the arc  
strike to enhance arc starting. This is factory set for  
a level (about 50% extra) which is usually good for  
most stick welding applications  
* The Preflow/Postflow Time doubling feature can also be selected  
on Precision TIG 275 models without the Advanced Panel by  
accessing the Control board in the control box per above instruc-  
tions, then disconnecting the jumper terminals attached to the  
jumper plug connected to receptacle J3 of the Control board.  
(Refer to Machine Wiring Diagram.)  
ON – Hot Start level is used (as shipped).  
OFF – No Hot Start.  
PRECISION TIG 275  
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B-10  
B-10  
OPERATION  
FIGURE B.3  
START/CRATER CURRENT  
UP-SLOPE  
2 Step Trigger Modes  
DOWN-SLOPE  
Torch  
Button  
Output  
Current  
Pre-Flow  
Post Flow  
Gas  
Normal Sequence  
2 Step - Restart Disabled  
(With DIP Switch #2 OFF)  
Torch  
Button  
Output  
Current  
Post Flow  
Pre-Flow  
Gas  
Actuate the trigger a second  
time, during down-slope, to  
immediately end down-slope.  
Hold the trigger to maintain  
crater current.  
2 Step - Restart Enabled  
(With DIP Switch #2 ON. As Shipped)  
Torch  
Button  
Output  
Current  
Pre-Flow  
Post Flow  
Gas  
Actuate the trigger a second  
time, during down-slope, to  
activate up-slope and restart.  
2
Step.eps  
12-17-07  
JRH  
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B-11  
B-11  
OPERATION  
FIGURE B.4  
START/CRATER CURRENT  
UP-SLOPE  
4 Step Trigger Modes  
DOWN-SLOPE  
Torch  
Button  
Output  
Current  
Pre-Flow  
Pre-Flow  
Post Flow  
Post Flow  
Gas  
Normal Sequence  
Hold the first trigger pull to maintain  
the starting current and delay  
up-slope.  
4 Step - Restart Enabled  
(With DIP Switch #3 ON)  
Torch  
Button  
Output  
Current  
Post Flow  
Post Flow  
Pre-Flow  
Gas  
Hold the second trigger  
pull for more than 1  
second to activate the  
restart function. When the  
trigger is released  
Actuate the trigger  
holding it less than 1  
second, to begin  
normal down-slope.  
The following two  
options are available  
during the normal  
down-slope period.  
Actuate the trigger  
again, during  
down-slope, to  
immediately end  
down-slope and stop.  
Or actuate and hold the trigger,  
during down-slope, to immediately  
end down-slope and maintain  
crater current. Hold the trigger for  
more than 1 second to activate the  
restart function. When the trigger  
is released up-slope will occur.  
up-slope will occur.  
4 Step - Restart Disabled  
(With DIP Switch #3 OFF. As Shipped)  
Torch  
Button  
Output  
Current  
Post Flow  
Post Flow  
Post Flow  
Pre-Flow  
Gas  
Hold the second trigger  
pull for more than 1  
second to maintain  
crater current before  
stopping.  
Actuate the trigger  
holding it less than 1  
second, to begin  
normal down-slope.  
The following two  
options are available  
during the normal  
down-slope period.  
Actuate the trigger a third  
time, during down-slope, to  
immediately end down-slope  
and stop.  
Or actuate the trigger a third time,  
during down-slope, to immediately  
end down-slope. Hold the third trigger  
pull to maintain crater current.  
4
Step.eps  
12-17-07  
JRH  
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B-12  
B-12  
OPERATION  
TIG WELD CYCLE CHART  
CODES BELOW 11000 (K1829-1)  
With PULSE ON  
No Pulsing  
2 or 4-STEP  
Trigger  
Closed  
4-STEP  
4-STEP Trigger  
Re-closed or  
2-STEP Trigger  
Opened  
4-STEP Trigger  
Re-opened  
after  
Trigger  
1ST Open  
During Upslope Time  
or  
Downslope Time  
When Downslope  
Drops Below  
Background Setting  
MAXIMUM OUTPUT  
SETTING  
Adjustable 2-Max.A  
CRATER-FILL  
LEVEL  
Advanced  
Panel Select:  
Amptrol or Remote  
Mach. Min.  
or  
MIN. Setting  
(as w/o Panel)  
(PEAK) Range  
PULSE FREQ.  
Adjustable  
0.1-20 pps  
% ON TIME  
Adjustable  
5-95%  
MINIMUM OUTPUT  
(Start) SETTING  
Adjustable 2-50A  
BACKGROUND  
Adjustable  
MIN.Setting -100% Peak  
POSTFLOW  
Adjust 2-60 sec  
or x2  
PREFLOW  
Fixed 0.5 sec  
or x2  
UPSLOPE  
Fixed<0.5 sec  
w/o Amptrol  
DOWNSLOPE  
Adjust 0 –10 sec  
w/ Advan. Panel  
(Fixed 0 sec w/o)  
START TIME  
CRATER-FILL TIME  
Manual  
Manual in 2/4-Step  
in 4-Step  
w/ Restart Disabled  
CODES ABOVE 11000 (K2621-1)  
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B-13  
B-13  
OPERATION  
FIGURE B.6  
Standard Controls  
Setup for TIG Amptrol Welding  
Power Switch  
ON  
Mode Switch  
TIG  
Polarity Switch  
AC Balance  
AUTO  
or  
AC or DC-  
Set:  
More +  
for alum. oxide “Cleaning“  
w/o “spitting”or“wetting“ loss.  
+
-
Balanced for equal and current.  
-
More  
for higher “Penetration“.  
Local/Remote  
Switch  
REMOTE  
Maximum Output  
Set to desired max.  
Amptrol output level.  
Minimum Output  
Press Display switch  
and Set to desired min.  
Amptrol (Start/Crater)  
output level.  
Min. to Max.  
Amptrol  
Max. to Min.  
Amptrol  
Postflow  
Set as low as required.  
Higher for larger  
tungsten and current.  
Advanced Panel  
(If used)  
Trigger Switch  
2-STEP  
Pulse Frequency  
Pulse Switch  
4-6 pps is a typical initial setting.  
Set for bead shape and travel speed:  
Higher for thinner plate and faster travel.  
Lower for thicker plate and slower travel.  
ON  
or  
OFF  
% On Time  
40-60% is a typical initial setting.  
Set for total heat of Peak current:  
Lower reduces distortion and burn-thru.  
Background Current  
40-60% is a typical initial setting.  
Set as low as will maintain a pulse arc  
Downslope  
ZERO  
For no arc-out delay.  
Advanced Panel  
Controls  
Min.Output  
(Will not drop below  
setting.)  
SETUP GUIDELINES FOR TIG WELDING  
WITH AN AMPTROL  
It is important to note that even with the Precision TIGʼs  
TM  
new MicroStart Technology, some tungsten may be  
difficult to start at the low (2 amps) minimum rating of  
the machine. Rather than guessing where to depress  
the Amptrol to start the arc reliably, the Minimum  
Output control allows presetting the exact level, so reli-  
able starts, as well as minimum crater-fill levels, can be  
consistently obtained at the minimum Amptrol (inacti-  
vated ) state. FIGURE B.6 shows Precision TIG setup  
for TIG welding with an Amptrol.  
Both the Hand and Foot Amptrols work in a similar  
manner. They are meant to be used for remote current  
control for TIG welding using the machineʼs 2-Step trig-  
ger mode (See Item 12).  
The Amptrol is capable of controlling the output of the  
Precision TIG over the range between the level preset  
by the Minimum Output control when the Amptrol is at  
its inactivated state, and the level preset by the  
Maximum Output control when the Amptrol is at fully-  
activated state.  
PRECISION TIG 275  
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B-14  
B-14  
OPERATION  
Close the arc start switch. This opens the gas valve  
to automatically purge air from the hose and torch,  
then shields the arc strike area. After the 0.5 sec-  
ond preflow time, the high frequency becomes  
available to strike the arc. When the arc strikes the  
torch coolant (if used) starts to flow. Also, if welding  
DC- TIG, the high frequency shuts off just after the  
arc strikes.  
MAKING A TIG WELD WITH AN AMPTROL  
1. Install welding equipment per Section A-5.  
2. Setup controls per Section B-9.  
3. Turn on the shielding gas supply, and torch coolant  
input supply (if used).  
Note: The Precision TIG Under-Cooler (or Water  
Solenoid connected to the Cooler receptacle) runs with  
the Fan-As-Needed machine cooling fan (See  
Maintenance Section D), so the cooler fan and water  
pump will also not run continuously in idle, but will run  
while welding.  
6. Hold the arc start switch closed at minimum Amptrol  
Start level (See Section B-10) until an arc is estab-  
lished, then increase the output to the desired weld-  
ing level and push the torch in the direction of trav-  
el.  
7. At the end of the weld, decrease the Amptrol output  
to the crater-fill level before releasing the arc start  
switch to start the Postflow time. Hold the torch gas  
shielding over the solidifying weld crater while post-  
flow time expires and the gas valve reopens. The  
torch coolant (if used) continues to flow for up to 8  
minutes after the arc goes out (with the Fan-As-  
Needed feature) to assure torch cooling.  
4. With the torch held safely away from everything,  
close the Arc Start Switch of the Amptrol and set the  
gas flow meter. Then open the switch. The welder  
is now ready for welding.  
5. Position the tungsten electrode at the start of the  
weld at a 65° to 75° angle with the horizontal, in the  
direction of pushing travel, so that the electrode is  
approximately 1/8" (4 mm) above the work piece.  
• Repeat steps 5 through 7 to make another weld.  
RECOMMENDED ELECTRODE AMPERAGE RANGES - PRECISION TIG 275  
SMAW Process  
ELECTRODE  
Fleetweld 5P, Fleetweld 5P+  
Fleetweld 180  
POLARITY  
DC+  
3/32"  
40 - 70  
40 - 80  
70 - 95  
75 - 95  
85 - 110  
40 - 80  
40 - 70  
1/8"  
5/32"  
75 - 130  
55 - 110  
100 - 135  
100 - 145  
110 - 160  
75 - 110  
60 - 100  
90 - 175  
105 - 135  
145 - 180  
135 - 200  
130 - 220  
95 - 110  
90 - 140  
DC+  
Fleetweld 37  
DC+  
Fleetweld 47  
DC-  
Jet-LH MR  
DC+  
Blue Max Stainless  
Red Baron Stainless  
DC+  
DC+  
Mild steel procedures are based on recommended procedures listed in C2.10 8/94 and the maximum rating of the PRECISION TIG 275  
Excaliber 7018 procedures are based on Jet-LH 78 MR  
Blue Max procedures are based on C6.1 6/95  
Red Baron Procedure are based on ES-503 10/93  
GTAW Process  
Electrode Polarity  
DC-  
AC*  
Approximate Argon  
Gas Flow Rate  
C.F.H. (l/min.)  
Electrode Tip Preparation  
Sharpened  
Balled  
EWZr  
Electrode Type  
EWTh-1, EWCe-2  
EWTh-2, EWLa-1  
EWG  
EWTh-1, EWTh-2  
EWCe-2, EWLa-1  
EWG  
EWP  
Stainless  
Steel  
Electrode Size (in.)  
Aluminum  
.010  
.020  
.040  
1/16  
3/32  
1/8  
Up to 15 A.  
Up to 15 A.  
Up to 80 A.  
Up to 150 A.  
Up to MAX. A.  
X
Up to 15 A.  
10 to 15 A.  
20 to 30 A.  
30 to 80 A.  
60 to 130 A.  
100 to 180 A.  
Up to 15 A.  
3-8  
(2-4) 3-8  
(2-4)  
5 to 20 A.  
5-10  
5-10  
5-10  
(3-5) 5-10 (3-5)  
(3-5) 5-10 (3-5)  
(3-5) 9-13 (4-6)  
20 to 60 A.  
60 to 120 A.  
100 to 180 A.  
160 to 250 A.  
13-17 (6-8) 11-15 (5-7)  
15-23 (7-11) 11-15 (5-7)  
Tungsten electrodes are classified as follows by the American Welding Society (AWS):  
Pure.........................................EWP...........green  
+1% Thoria..............................EWTh-1......yellow  
+2% Thoria..............................EWTh-2......red  
+2% Ceria................................EWCe-2 .....orange  
+1.5% Lanthana ......................EWLa-1......black  
+0.15 to 0.40% Zirconia ..........EWZr..........brown  
Ceriated Tungsten is now widely accepted as a substitute for 2% Thoriated Tungsten in AC and DC applications.  
Balanced Wave, Unbalanced Wave requires derating of the elePctrRodeE. CISION TIG 275  
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TABLE OF CONTENTS  
- ACCESSORIES -  
C-1  
C-1  
Accessories...........................................................................................................................Section C  
Optional Equipment for Codes Below 11000..............................................................................C-2  
Optional Equipment for Codes Above 11000..............................................................................C-3  
PRECISION TIG 275  
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C-2  
C-2  
ACCESSORIES FOR CODES BELOW 11000  
• K870 Foot Amptrol  
OPTIONAL EQUIPMENT  
FACTORY INSTALLED OPTIONS  
Single pedal foot activation of arc start switch and  
output control, with 25ʼ plug cable.  
• K870-1 Start Pedal Foot Amptrol  
The basic Precision TIG 275 machine is factory  
equipped with:  
Independent start pedal on control pedal provides  
two-stage foot action to easily feel start switch clo-  
sure at minimum output level for enhanced arc start  
and crater-fill control. Provided with adjustable, or  
removable , heel stop and 25ʼ plug cable.(Refer to  
Figure B.5)  
• A 3/8" Adapter (S20403-4) for air cooled torch con-  
nection of a PTA-9 or PTA-17.  
Accessories that are factory installed with the  
Domestic model (K1826-1) to make up the Domestic  
Welding Package (K1825-1) include:  
• K963-3 Hand Amptrol  
Fastens to torch for convenient thumb activation of  
arc start switch and output control, with 25ʼ plug  
cable:  
• K1828-1  
• 3100211  
Under-Cooler Cart  
Harris Argon Flow Regulator with 10ʼ  
Hose.  
K963-1 is for PTA-9,-17 and PTW-20 Torches.  
K963-2 is for PTA-26 and PTW-18 Torches.  
• K870 Foot Amptrol  
• K1784-4  
• K918-2  
• KP510  
25ʼ PTW-20 water-cooled TIG Torch  
• K814 Arc Start Switch  
Zippered Torch Cover  
Parts Kit for Torch  
Needed for TIG welding without an Amptrol. Includes  
25ʼ plug cable, and attaches to torch for convenient  
finger control.  
• K2150-1  
Work Lead Assembly  
See below for more detailed descriptions.  
FIELD INSTALLED OPTIONS  
• K1831-1 Power Factor Capacitor Kit  
Used when welding at higher output currents to  
reduce input current and help keep electricity costs  
to a minimum.  
The following Options/Accessories are available for the  
Precision TIG 275 and are installed per instructions in  
this manual and / or provided in the package:  
• Magnum® PTA and PTW Series Torches  
All Air Cooled or Water-Cooled Magnum® TIG  
Torches may be used with the PRECISION TIG 275.  
Connection adapters are only required for Air-Cooled  
Torches (Refer to Diagrams on A-7):  
• K1829-1 Precision TIG Advanced Control Panel  
Provides 2/4-step trigger with adjustable Pulser con-  
trols and Down slope timer for TIG welding. Also  
includes adjustable Hot Start and Arc Force internal  
panel controls for Stick welding, and other user  
selectable features.  
K2166-1 7/8” Torch Connector for PTA-26 (one  
piece)  
• K1828-1 Under-Cooler Cart  
K2166-2 1/2” stud Connector for PTA Torch (two-  
piece).  
Includes a "cooler-in-a-drawer" with hoses and a  
lockable storage drawer on a dual bottle undercar-  
riage (see below).  
K2166-3 3/8” TIG Torch Connector for PTA-9,-17  
(one piece). (Included as S20403-4 with Precision  
TIG models.)  
• K1869-1 Undercarriage  
Includes a dual bottle rack with chain and an under-  
carriage with 5" front casters,10" rear wheels and a  
handle.  
• 3100211 Harris Argon Flow Regulator (Includes 10ʼ  
hose.)  
• K1830-1 Water Solenoid Kit  
• K2150-1 Work Lead Assembly  
Provides for stopping flow of external water supply.  
Connects to coolant inlet and cooler receptacle of  
Precision TIG.  
15ft. 2/0 cable with 1/2" stud lug and work clamp.  
(Cannot be used with a water cooler.)  
PRECISION TIG 275  
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C-3  
C-3  
ACCESSORIES FOR CODES ABOVE 11000  
• K870 Foot Amptrol  
OPTIONAL EQUIPMENT  
FACTORY INSTALLED OPTIONS  
Single pedal foot activation of arc start switch and  
output control, with 25ʼ plug cable.  
• K963-3-3 Hand Amptrol  
The basic Precision TIG 275 machine is factory  
equipped with:  
Fastens to torch for convenient thumb activation of  
arc start switch and output control, with 25ʼ plug  
cable:  
• A 3/8" Adapter (S20403-4) for air cooled torch con-  
nection of a PTA-9 or PTA-17.  
• K814 Arc Start Switch  
Needed for TIG welding without an Amptrol. Includes  
25ʼ plug cable, and attaches to torch for convenient  
finger control.  
Accessories that are factory installed with the  
Domestic model (K1826-1) to make up the Domestic  
Welding Package (K1825-1) include:  
• K1831-1 Power Factor Capacitor Kit  
Used when welding at higher output currents to  
reduce input current and help keep electricity costs  
to a minimum.  
• K1828-1  
• 3100211  
Under-Cooler Cart  
Harris Argon Flow Regulator with 10ʼ  
Hose.  
• K870 Foot Amptrol  
• K1784-4  
• K918-2  
• KP510  
25ʼ PTW-20 water-cooled TIG Torch  
• Magnum® PTA and PTW Series Torches  
Zippered Torch Cover  
Parts Kit for Torch  
All Air Cooled or Water-Cooled Magnum® TIG  
Torches may be used with the PRECISION TIG 275.  
Connection adapters are only required for Air-Cooled  
Torches (Refer to Diagrams on A-7):  
• K2150-1  
Work Lead Assembly  
See below for more detailed descriptions.  
FIELD INSTALLED OPTIONS  
K2166-1 7/8” Torch Connector for PTA-26 (one  
piece)  
The following Options/Accessories are available for the  
Precision TIG 275 and are installed per instructions in  
this manual and / or provided in the package:  
K2166-2 1/2” stud Connector for PTA Torch (two-  
piece).  
• K2621-1 Precision TIG Advanced Control Panel  
Provides 2/4-step trigger with adjustable Pulser  
controls and Down slope timer for TIG welding. Also  
includes adjustable Hot Start and Arc Force internal  
panel controls for Stick welding, and other user  
selectable features.  
K2166-3 3/8” TIG Torch Connector for PTA-9,-17  
(one piece). (Included as S20403-4 with Precision  
TIG models.)  
• 3100211 Harris Argon Flow Regulator (Includes 10ʼ  
hose.)  
• K1828-1 Under-Cooler Cart  
• K2150-1 Work Lead Assembly  
Includes a "cooler-in-a-drawer" with hoses and a  
lockable storage drawer on a dual bottle undercar-  
riage (see below).  
15ft. 2/0 cable with 1/2" stud lug and work clamp.  
• K1869-1 Undercarriage  
Includes a dual bottle rack with chain and an under-  
carriage with 5" front casters,10" rear wheels and a  
handle.  
• K1830-1 Water Solenoid Kit  
Provides for stopping flow of external water supply.  
Connects to coolant inlet and cooler receptacle of  
Precision TIG.  
(Cannot be used with a water cooler.)  
PRECISION TIG 275  
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C-4  
C-4  
NOTES  
PRECISION TIG 275  
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TABLE OF CONTENTS  
-MAINTENANCE-  
D-1  
D-1  
Maintenance ..........................................................................................................................Section D  
Safety Precautions......................................................................................................................D-2  
Routine and Periodic Maintenance.............................................................................................D-2  
Overload Protection ....................................................................................................................D-2  
Fan As Needed (F.A.N.)..............................................................................................................D-2  
Service Procedures.....................................................................................................................D-3  
Component Location and Access ...............................................................................................D-3  
Spark Gap Adjustment................................................................................................................D-3  
Major Component Location.........................................................................................................D-4  
PRECISION TIG 275  
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D-2  
D-2  
MAINTENANCE  
SAFETY PRECAUTIONS  
OVERLOAD PROTECTION  
FAN-AS-NEEDED (F.A.N.)  
WARNING  
The Precision TIG 275 has the F.A.N. circuit feature,  
which means the cooling fan will operate only while  
welding; then for about 8 minutes after welding has  
stopped to assure proper machine cooling. This helps  
reduce the amount of dust and dirt drawn into the  
machine with the cooling air. The cooling fan will oper-  
ate briefly when the machine power is initially turned  
on, and continuously while the yellow Thermal  
Shutdown Light is lit (see Thermostatic Protection).  
ELECTRIC SHOCK can kill.  
• Only qualified personnel should  
perform this maintenance.  
• Turn the input power OFF at the  
disconnect switch or fuse box  
before working on this  
equipment.  
• Do not touch electrically hot  
parts.  
THERMOSTATIC PROTECTION  
This welder has thermostatic protection from excessive  
duty cycles, overloads, loss of cooling, and excessive  
ambient temperatures. When the welder is subjected  
to an overload, or inadequate cooling, the primary coil  
thermostat and/or secondary coil thermostat will open.  
This condition will be indicated by the illumination of  
the yellow Thermal Shutdown Light on the front panel  
(see Item 10 in Section B). The fan will continue to run  
to cool the power source. Postflow occurs when TIG  
welding is shut down, but no welding is possible until  
the machine is allowed to cool and the yellow Thermal  
Shutdown Light goes out.  
WARNING  
To avoid receiving a high frequency shock, keep the  
TIG torch and cables in good condition.  
ROUTINE AND PERIODIC MAINTENANCE  
Very little routine maintenance is necessary to keep  
your Precision TIG 275 running in top condition. No  
specific schedule can be set for performing the follow-  
ing items; factors such as hours of usage and machine  
environment should be considered when establishing  
a maintenance schedule.  
NO ARC PROTECTION  
The machine outputs (Background / OCV, gas and HF)  
will be shutdown, if the trigger is closed without weld-  
ing for 15 seconds to protect the Background resistor  
from overheating with F.A.N. cooling off, as well as to  
conserve on gas waste.  
• Periodically blow out dust and dirt which may accu-  
mulate within the welder using an air stream.  
• Inspect welder output and control cables for fraying,  
cuts, and bare spots.  
AUXILIARY POWER CIRCUIT BREAKER  
• Inspect the spark gap at regular intervals to maintain  
the recommended spacing. See the Service  
Procedures (See Service Procedures in this  
Section) for complete information on spark gap set-  
tings.  
The 115vac auxiliary circuits and rear receptacle (see  
Section A Auxiliary Power Connections) are protected  
from overloads by a 15 amp circuit breaker, located  
above the receptacle. If the breaker trips its button  
pops out exposing a red ring. When the circuit breaker  
cools the button can be reset by pressing it back in.  
Note: When the breaker trips not only will the recepta-  
cleʼs auxiliary and cooler power be interrupted, but so  
will the power to the shielding gas solenoid and  
machine cooling fan.  
• The fan motor has sealed ball bearings which  
require no maintenance.  
The Export models also include a 5 amp circuit break-  
er, located on the opposite side of the upper case back,  
for protection of the 220 VAC Schuko type cooler  
receptacle.  
PRECISION TIG 275  
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D-3  
D-3  
MAINTENANCE  
FIGURE C.1 SPARK GAP  
SERVICE PROCEDURES  
Operation of the Precision TIG should be trouble-free  
for the life of the machine. Should a malfunction occur,  
however, the following procedures will be useful to  
trained service personnel with experience in repairing  
arc welding equipment:  
.015 Spark Gap  
COMPONENT ACCESS  
Note: In highly dirty environments where there is an  
abundance of conductive contaminants, use a low  
pressure air stream or a firm piece of paper to clean  
out the spark gap. Do not disturb the factory gap set-  
ting.  
The following components are accessible for routine  
set up and periodic service without requiring removal  
of the case sides or roof:  
• Input Reconnect Panel (refer Section A) is located  
behind a removable panel on the rear of the left case  
side. Remove the two screws (with a screwdriver or  
a 3/8"/ 9.5mm hex driver) on the bottom corners of  
this panel to remove it.  
To check the spark gap:  
1. Turn the input power off per above.  
2. Remove the access panel on the right case side  
(See Component Access).  
3. Check the spark gap spacing with a feeler gauge.  
• Control Box components and PC Boards (refer  
Section B-6) are located behind the front control  
panel. Remove the two screws (with a screwdriver or  
a 3/8"/ 9.5mm hex driver) on the top corners of this  
panel to swing it down.  
If adjustment is required:  
1. Adjust the gap by loosening the Allen head screw  
on one of the aluminum blocks, reset the gap and  
tighten the screw in the new position.  
• Hi-Freq. Spark Gap Assembly (refer Spark Gap  
Adjustment) is located behind a removable panel on  
the rear of the right case side, under the torch box.  
Remove the screw (with a screwdriver or a 3/8"/  
9.5mm hex driver) on the bottom center of this panel  
to remove it.  
If spark gap is correct:  
1. Reinstall the access panel on the right case side.  
UNDER-COOLER SERVICE  
The required maintenance and service instructions for  
the Under-Cooler are provided in the operatorʼs manu-  
al (IM723) provided with the Under-Cooler Cart.  
SPARK GAP ADJUSTMENT  
The spark gap is set at the factory to a gap of 0.015  
inches (0.4 mm) See Figure C.1. This setting is ade-  
quate for most applications. Where less high frequen-  
cy is desired, the setting can be reduced to 0.008 inch-  
es (0.2 mm).  
WARNING  
Use extreme caution when working with the high  
frequency circuit. The high voltages developed can  
be lethal. Turn the input power off using the dis-  
connect switch or fuse box before working inside  
the machine. This is particularly important when  
working on the secondary circuit of the high volt-  
age transformer (T3) because the output voltage is  
dangerously high.  
------------------------------------------------------------------------  
PRECISION TIG 275  
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D-4  
D-4  
MAINTENANCE  
1. Case Front Assembly  
2. Arc Starter and Bypass Assembly  
3. Case Back Assembly  
4. Center Assembly  
5. Case Cover Assembly  
5
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PRECISION TIG 275  
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E-1  
E-1  
TABLE OF CONTENTS  
-THEORY OF OPERATION SECTION-  
Theory of Operation..............................................................................................................Section E  
General Description ....................................................................................................................E-2  
Input Power Circuit......................................................................................................................E-2  
Output Rectification, Control Board and Feedback ....................................................................E-3  
High Voltage/High Frequency Circuit..........................................................................................E-4  
DC Welding Output .....................................................................................................................E-5  
AC Welding Output .....................................................................................................................E-6  
SCR Operation............................................................................................................................E-7  
Protective Circuits .......................................................................................................................E-8  
Fan As Needed (F.A.N.)........................................................................................................E-8  
Thermal Protection ...............................................................................................................E-8  
Overload Protection..............................................................................................................E-8  
FIGURE E.1 – PRECISION TIG 275 BLOCK LOGIC DIAGRAM  
BACKGROUND  
CIRCUIT  
FROM  
CONTROL  
BOARD  
REAR GANG  
WORK  
POLARITY  
SWITCH  
OPTIONAL POWER  
FACTOR  
BYPASS  
BOARD  
CORRECTION  
CAPACITORS  
FRONT  
ELECTRODE  
HIGH FREQUENCY  
TRANSFORMER  
POWER  
SWITCH  
X1  
X2  
REAR  
ELECTRODE  
DC  
AC  
HIGH VOLTAGE  
TRANSFORMER  
SCR  
BRIDGE  
DC  
AC  
SHUNT  
115 VAC  
GAS  
THERMOSTAT  
FAN  
SOLENOID  
115 VAC  
20 VAC  
THERMOSTAT  
CONTROL BOARD  
20 VAC  
LED's  
ADVANCED CONTROL  
PANEL RECEPTACLE  
MINIMUM  
OUTPUT  
PROTECTION  
BOARD  
STICK  
CONTROL  
METER  
TIG  
SWITCH  
LOCAL/REMOTE  
SWITCH  
BALANCE  
CONTROL  
POST  
FLOW  
MAXIMUM  
OUTPUT  
CONTROL  
REMOTE  
RECEPTACLE  
PRECISION TIG 275  
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E-2  
E-2  
THEORY OF OPERATION  
FIGURE E.2 – GENERAL DESCRIPTION AND INPUT POWER CIRCUIT  
BACKGROUND  
CIRCUIT  
FROM  
CONTROL  
BOARD  
REAR GANG  
WORK  
POLARITY  
SWITCH  
OPTIONAL POWER  
FACTOR  
BYPASS  
BOARD  
CORRECTION  
CAPACITORS  
FRONT  
ELECTRODE  
HIGH FREQUENCY  
TRANSFORMER  
POWER  
SWITCH  
X1  
X2  
REAR  
ELECTRODE  
AC  
DC  
HIGH VOLTAGE  
TRANSFORMER  
SCR  
BRIDGE  
AC  
DC  
SHUNT  
115 VAC  
GAS  
THERMOSTAT  
FAN  
SOLENOID  
115 VAC  
20 VAC  
THERMOSTAT  
CONTROL BOARD  
20 VAC  
LED's  
ADVANCED CONTROL  
PANEL RECEPTACLE  
MINIMUM  
OUTPUT  
PROTECTION  
BOARD  
STICK  
CONTROL  
METER  
TIG  
SWITCH  
LOCAL/REMOTE  
SWITCH  
BALANCE  
CONTROL  
POST  
FLOW  
MAXIMUM  
OUTPUT  
CONTROL  
REMOTE  
RECEPTACLE  
the reconnect panel. When the input power switch is  
turned “on,” the input voltage is applied directly to the  
primary winding of the main transformer.  
GENERAL DESCRIPTION  
The PRECISION TIG 275 is part of a new family of  
industrial arc welding power sources able to provide  
constant current and single range square wave AC/DC  
The main transformer changes the high voltage, low  
current input power to a low voltage, high current out-  
put available at the main secondary winding (X1 and  
X2). This 78 VAC winding supplies power to the weld-  
ing arc. In addition, four auxiliary windings are incor-  
porated in the main transformer. The 115 VAC winding  
supplies power to the 115 VAC receptacle. Through  
the control board, it also powers the gas solenoid, the  
high voltage transformer, and the cooling fan. The  
cooling fan is activated only when welding current is  
sensed. The 63.5 VAC winding provides power for the  
DC background current. This circuit is active in the DC  
TIG welding mode. The 20 VAC windings are included  
in the main transformer assembly. The 20 VAC winding  
is rectified on the control board and is used in the trig-  
ger circuitry. The other 20 VAC winding is used by the  
control board for phase detection. This AC voltage is  
also rectified to several DC voltages and regulated to  
+15 VDC and +5 VDC power supplies that operate the  
circuitry on the control board.  
TM  
Tig (GTAW) with new MicroStart Technology. It incor-  
porates independent presettable minimum and maxi-  
mum output control with built-in high frequency stabi-  
lization for continuous AC Tig welding and reliable DC  
Tig starting. The Precision TIG 275 also has AC/DC  
stick (SMAW) capabilities. This new design includes  
advanced features such as a digital meter, presettable  
TM  
controls, auto balance , fan as needed and timers for  
fixed preflow and variable post flow of shielding gas. It  
features a stick output terminal (front) and a universal  
Tig torch connection box (rear) for simultaneous, but  
separate, electrode outputs.  
INPUT POWER CIRCUIT  
The desired single-phase input power is connected to  
the PRECISION TIG 275 through the power switch to  
the reconnect panel located in the rear of the machine.  
The machine can be configured for any one of three  
input voltages (208 VAC, 230 VAC or 460 VAC) by con-  
necting the jumper strap to the appropriate terminal on  
NOTE: Unshaded areas of Block Logic Diagram are the subject of discussion.  
PRECISION TIG 275  
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E-3  
E-3  
THEORY OF OPERATION  
FIGURE E.3 – OUTPUT RECTIFICATION, CONTROL BOARD AND FEEDBACK  
BACKGROUND  
CIRCUIT  
FROM  
CONTROL  
BOARD  
REAR GANG  
WORK  
POLARITY  
SWITCH  
OPTIONAL POWER  
FACTOR  
BYPASS  
BOARD  
CORRECTION  
CAPACITORS  
FRONT  
ELECTRODE  
HIGH FREQUENCY  
TRANSFORMER  
POWER  
SWITCH  
X1  
X2  
REAR  
ELECTRODE  
DC  
AC  
HIGH VOLTAGE  
TRANSFORMER  
SCR  
BRIDGE  
DC  
AC  
SHUNT  
115 VAC  
GAS  
THERMOSTAT  
FAN  
SOLENOID  
115 VAC  
20 VAC  
THERMOSTAT  
CONTROL BOARD  
20 VAC  
LED's  
ADVANCED CONTROL  
PANEL RECEPTACLE  
MINIMUM  
OUTPUT  
PROTECTION  
BOARD  
STICK  
CONTROL  
METER  
TIG  
SWITCH  
LOCAL/REMOTE  
SWITCH  
BALANCE  
CONTROL  
POST  
FLOW  
MAXIMUM  
OUTPUT  
CONTROL  
REMOTE  
RECEPTACLE  
OUTPUT RECTIFICATION,  
CONTROL BOARD AND FEEDBACK  
The AC output from the main transformer secondary  
is rectified and controlled through the SCR bridge.  
Output current is sensed at the shunt as a low voltage  
signal and fed back to the control board. The control  
board senses the status and settings of the various  
operator controls such as the Stick/TIG switch, the  
output controls, the remote control receptacle, the  
local/remote switch, the balance control and the post-  
flow control. Circuitry on the control board evaluates  
these commands, compares them to the feedback  
information received from the shunt and sends the  
appropriate gate firing signals to the output SCR  
bridge. The control board regulates the firing of the  
output SCRs, which control the output of the machine.  
See SCR Operation.  
The control board also monitors the thermostats and  
controls the gas solenoid, the thermal light, the high  
voltage transformer and the cooling fan. The optional  
advanced control panel also plugs into and interfaces  
with the control board.  
PRECISION TIG 275  
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E-4  
E-4  
THEORY OF OPERATION  
FIGURE E.4 – HIGH VOLTAGE / HIGH FREQUENCY CIRCUIT  
BACKGROUND  
CIRCUIT  
FROM  
CONTROL  
BOARD  
REAR GANG  
WORK  
POLARITY  
SWITCH  
OPTIONAL POWER  
FACTOR  
BYPASS  
BOARD  
CORRECTION  
CAPACITORS  
FRONT  
ELECTRODE  
HIGH FREQUENCY  
TRANSFORMER  
POWER  
SWITCH  
X1  
REAR  
ELECTRODE  
DC  
AC  
X2  
HIGH VOLTAGE  
TRANSFORMER  
SCR  
BRIDGE  
DC  
AC  
SHUNT  
115 VAC  
GAS  
THERMOSTAT  
FAN  
SOLENOID  
115 VAC  
20 VAC  
THERMOSTAT  
CONTROL BOARD  
20 VAC  
LED's  
ADVANCED CONTROL  
PANEL RECEPTACLE  
MINIMUM  
OUTPUT  
PROTECTION  
BOARD  
STICK  
CONTROL  
METER  
TIG  
SWITCH  
LOCAL/REMOTE  
SWITCH  
BALANCE  
CONTROL  
POST  
FLOW  
MAXIMUM  
OUTPUT  
CONTROL  
REMOTE  
RECEPTACLE  
HIGH VOLTAGE/HIGH FREQUENCY  
CIRCUIT  
The control board passes the 115 VAC voltage to the  
primary of the high voltage transformer. The secondary  
of the high voltage transformer is coupled to a spark  
gap generator and also to the primary winding of the  
high frequency transformer. The secondary of the high  
frequency transformer is in series with the rear elec-  
trode output terminal. The high frequency “spark” is  
present at the electrode terminal and is transferred to  
the Tig torch.  
NOTE: Unshaded areas of Block Logic Diagram are the subject of discussion.  
PRECISION TIG 275  
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E-5  
E-5  
THEORY OF OPERATION  
FIGURE E.5 – DC WELDING OUTPUT  
BACKGROUND  
CIRCUIT  
FROM  
CONTROL  
BOARD  
REAR GANG  
WORK  
POLARITY  
SWITCH  
OPTIONAL POWER  
FACTOR  
BYPASS  
BOARD  
CORRECTION  
CAPACITORS  
FRONT  
ELECTRODE  
HIGH FREQUENCY  
TRANSFORMER  
POWER  
SWITCH  
X1  
REAR  
ELECTRODE  
AC  
DC  
X2  
HIGH VOLTAGE  
TRANSFORMER  
SCR  
BRIDGE  
AC  
DC  
SHUNT  
115 VAC  
GAS  
THERMOSTAT  
FAN  
SOLENOID  
115 VAC  
20 VAC  
THERMOSTAT  
CONTROL BOARD  
20 VAC  
LED's  
ADVANCED CONTROL  
PANEL RECEPTACLE  
MINIMUM  
OUTPUT  
PROTECTION  
BOARD  
STICK  
CONTROL  
METER  
TIG  
SWITCH  
LOCAL/REMOTE  
SWITCH  
BALANCE  
CONTROL  
POST  
FLOW  
MAXIMUM  
OUTPUT  
CONTROL  
REMOTE  
RECEPTACLE  
DC WELDING OUTPUT  
When the machine is in the DC mode, the background cir-  
cuitry provides an added boost of voltage to the output  
terminals. This circuitry is controlled by the control board.  
When the polarity switch is placed in either DC position, the  
AC voltage from the main transformer secondary is applied  
to the SCR bridge. The SCR bridge and choke circuits are  
connected in the conventional full wave bridge and filter  
configuration, resulting in a controlled DC output. Since  
the choke is in series with the negative leg of the bridge  
and also in series with the welding load, a filtered DC is  
applied to the output terminals. The bypass board pro-  
tects the internal circuitry from interference.  
FIGURE E.6 DC WELDING CURRENT GENERATION  
CHOKE  
ELECTRODE  
G
G
DC  
PRIMARY  
10  
G
G
WORK  
PRECISION TIG 275  
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E-6  
E-6  
THEORY OF OPERATION  
FIGURE E.7 – AC WELDING OUTPUT  
BACKGROUND  
CIRCUIT  
FROM  
CONTROL  
BOARD  
REAR GANG  
WORK  
POLARITY  
SWITCH  
OPTIONAL POWER  
FACTOR  
BYPASS  
BOARD  
CORRECTION  
CAPACITORS  
FRONT  
ELECTRODE  
HIGH FREQUENCY  
TRANSFORMER  
POWER  
SWITCH  
X1  
X2  
REAR  
ELECTRODE  
DC  
AC  
HIGH VOLTAGE  
TRANSFORMER  
SCR  
BRIDGE  
DC  
AC  
SHUNT  
115 VAC  
GAS  
THERMOSTAT  
FAN  
SOLENOID  
115 VAC  
20 VAC  
THERMOSTAT  
CONTROL BOARD  
20 VAC  
LED's  
ADVANCED CONTROL  
PANEL RECEPTACLE  
MINIMUM  
OUTPUT  
PROTECTION  
BOARD  
STICK  
CONTROL  
METER  
TIG  
SWITCH  
LOCAL/REMOTE  
SWITCH  
BALANCE  
CONTROL  
POST  
FLOW  
MAXIMUM  
OUTPUT  
CONTROL  
REMOTE  
RECEPTACLE  
AC WELDING OUTPUT  
electrically across the negative and positive SCR  
bridge connections. With the ability of the choke to  
store energy and the SCRs to turn on at the appropri-  
ate times, an AC square wave is developed and  
applied to the output terminals. The bypass board pro-  
tects the internal circuitry from interference.  
Rotating the polarity switch to the AC position changes  
the welding power circuit. One lead (X1) of the main  
transformer secondary is connected to the machineʼs  
output work terminal. The other secondary lead (X2) is  
connected to one of the AC connections of the SCR  
bridge. The electrode terminal is connected to the  
other AC side of the bridge. The choke is now  
FIGURE E.8 DC WELDING CURRENT GENERATION  
CHOKE  
ELECTRODE  
DC  
PRIMARY  
10  
WORK  
PRECISION TIG 275  
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E-7  
E-7  
THEORY OF OPERATION  
FIGURE E.9 – SCR OPERATION  
INPUT  
CATHODE  
OUTPUT  
NOTE: AS THE GATE  
GATE  
GATE  
ANODE  
PULSE IS APPLIED  
LATER IN THE CYCLE  
THE SCR OUTPUT  
IS DECREASED.  
SCR OPERATION  
An SCR is fired by a short burst of current into the gate.  
This gate pulse must be more positive than the cath-  
ode voltage. Since there is a standard PN junction  
between gate and cathode, the voltage between these  
terminals must be slightly greater than 0.6V. Once the  
SCR has fired, it is not necessary to continue the flow  
of gate current. As long as current continues to flow  
from anode to cathode, the SCR will remain on. When  
the anode to cathode current drops below a minimum  
value, called holding current, the SCR will shut off.  
This normally occurs as the AC supply voltage passes  
through zero into the negative portion of the sine wave.  
If the SCR is turned on early in the positive half cycle  
the conduction time is longer, resulting in greater SCR  
output. If the gate firing occurs later in the cycle the  
conduction time is less, resulting in lower SCR output.  
A silicon controlled rectifier (SCR) is a three-terminal  
device used to control rather large currents to a load.  
An SCR acts very much like a switch. When a gate sig-  
nal is applied to the SCR, it is turned ON and there is  
current flow from anode to cathode. In the ON state  
the SCR acts like a closed switch. When the SCR is  
turned OFF there is no current flow from anode to cath-  
ode. Thus, the device acts like an open switch. As the  
name suggests, the SCR is a rectifier, so it passes cur-  
rent only during positive half cycles of the AC supply.  
The positive half cycle is the portion of the sine wave in  
which the anode of the SCR is more positive than the  
cathode.  
When an AC supply voltage is applied to the SCR, the  
device spends a certain portion of the AC cycle time in  
the ON state and the remainder of the time in the OFF  
state. The amount of time spent in the ON state is con-  
trolled by the gate.  
PRECISION TIG 275  
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E-8  
E-8  
THEORY OF OPERATION  
PROTECTION CIRCUITS  
Protection circuits are designed into the PRECISION  
Tig 275 machine to sense trouble and shut down the  
machine before the trouble damages internal machine  
components. Both thermal protection and current over-  
load are included.  
FAN-AS-NEEDED (F.A.N.)  
The PRECISION Tig 275 has the F.A.N. circuit feature,  
which means that the cooling fan will operate only  
while welding; then for about eight minutes after weld-  
ing has stopped to assure proper machine cooling.  
This helps reduce the amount of dirt and dust drawn  
into the machine along with the cooling air. The cooling  
fan will operate briefly when the machine power is ini-  
tially turned on, and continuously while the yellow  
Thermal shutdown light is lit.  
THERMAL PROTECTION  
This welder has thermostatic protection from excessive  
duty cycles, overloads, loss of cooling and excessive  
ambient temperatures. When the welder is subjected  
to an overload, or inadequate cooling, the primary coil  
thermostat and/or secondary coil thermostat will open.  
This condition will be indicated by the illumination of  
the yellow Thermal Shutdown light on the front panel.  
The fan will continue to run to cool the power source.  
Postflow occurs when Tig welding is shut down, but no  
welding is possible until the machine is allowed to cool  
and the yellow Thermal Shutdown light goes out. Once  
the machine cools sufficiently, the thermostats are self-  
resetting. If the shutdown is caused by excessive out-  
put or duty cycle and the fan is operating normally, the  
power may be left on and the reset should occur with-  
in a 15 minute period. If the fan is not functioning prop-  
erly or the air intake louvers are obstructed, the input  
power must be removed and the fan problem or air  
obstruction corrected.  
OVERLOAD PROTECTION  
The machine is electronically protected from producing  
excessively high output currents. The output is limited  
to 350 amps.  
PRECISION TIG 275  
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TABLE OF CONTENTS  
F-1  
F-1  
TROUBLESHOOTING & REPAIR SECTION  
Troubleshooting & Repair Section ................................................................................Section F  
How to Use Troubleshooting Guide.......................................................................................F-2  
PC Board Troubleshooting Procedures and Replacement....................................................F-3  
Troubleshooting Guide...........................................................................................................F-4  
Test Procedures  
Meter Calibration Adjustments ......................................................................................F-19  
High Frequency Circuit Disable Procedure...................................................................F-23  
Protection Board Test....................................................................................................F-25  
T1 Main Transformer Test .............................................................................................F-27  
Gas (Water) Solenoid Test ............................................................................................F-31  
Static SCR Test .............................................................................................................F-33  
Active SCR Test.............................................................................................................F-35  
Typical Output Voltage Waveform (DC Tig Mode) ........................................................F-39  
Typical Output Voltage Waveform (AC Tig Mode).........................................................F-40  
Typical AC Voltage Waveform - 50 AMPS (AC Tig Mode)............................................F-41  
Typical AC Voltage Waveform - 2 AMPS (AC Tig Mode)..............................................F-42  
Typical Output Voltage Waveform - 200 AMPS ( DC Tig Mode)..................................F-43  
Replacement Procedures  
High Voltage Transformer Removal & Replacement.....................................................F-45  
Control Board Removal and Replacement....................................................................F-49  
SCR Bridge Assembly Removal and Replacement ......................................................F-53  
Polarity Switch Removal and Replacement ..................................................................F-57  
SCR Removal and Replacement ..................................................................................F-59  
Retest after Repair ........................................................................................................F-61  
PRECISION TIG 275  
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F-2  
F-2  
TROUBLESHOOTING & REPAIR  
HOW TO USE TROUBLESHOOTING GUIDE  
WARNING  
Service and repair should be performed by only Lincoln Electric Factory Trained Personnel.  
Unauthorized repairs performed on this equipment may result in danger to the technician and machine  
operator and will invalidate your factory warranty. For your safety and to avoid Electrical Shock, please  
observe all safety notes and precautions detailed throughout this manual.  
This Troubleshooting Guide is provided to help  
you locate and repair possible machine malfunc-  
tions. Simply follow the three-step procedure list-  
ed below.  
Step 3.  
ACTION  
RECOMMENDED COURSE OF  
The  
last column, labeled “Recommended Course of  
Action” lists the most likely components that may  
have failed in your machine. It also specifies the  
appropriate test procedure to verify that the sub-  
ject component is either good or bad. If there are  
a number of possible components, check the  
components in the order listed to eliminate one  
possibility at a time until you locate the cause of  
your problem.  
Step 1. LOCATE PROBLEM (SYMPTOM). Look  
under the column labeled “PROBLEM” (SYMP-  
TOMS). This column describes possible symp-  
toms that the machine may exhibit. Find the list-  
ing that best describes the symptom that the  
machine is exhibiting. Symptoms are grouped  
into four main categories: Output Problems,  
Function Problems, Cutting Problems and LED  
Function Problems.  
All of the referenced test procedures referred to in  
the Troubleshooting Guide are described in detail  
at the end of this chapter.  
Refer to the  
Troubleshooting and Repair Table of Contents to  
locate each specific Test Procedure. All of the  
referred to test points, components, terminal  
strips, etc., can be found on the referenced elec-  
trical Wiring Diagrams and Schematics. Refer to  
the Electrical Diagrams Section Table of Contents  
to locate the appropriate diagram.  
Step 2.  
PERFORM EXTERNAL TESTS.  
The second column, labeled “POSSIBLE AREAS  
OF MISADJUSTMENT(S)”, lists the obvious  
external possibilities that may contribute to the  
machine symptom. Perform these tests/checks in  
the order listed. In general, these tests can be  
conducted without removing the case wrap-  
around cover.  
CAUTION  
CAUTION  
If for any reason you do not understand the test procedures or are unable to perform the test/repairs  
safely, contact the Lincoln Electric Service Department for electrical troubleshooting assistance before  
you proceed. Call 1-888-935-3877.  
WARNING  
HIGH VOLTAGE/ HIGH FREQUENCY can damage test equipment.  
* Perform all voltage and wave form checks with high frequency circuit OFF.  
Perform High Frequency Disable Procedure.  
PRECISION TIG 275  
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F-3  
F-3  
TROUBLESHOOTING & REPAIR  
PC BOARD TROUBLESHOOTING PROCEDURES  
• Remove the PC Board from the static-shielding bag  
and place it directly into the equipment. Donʼt set the  
PC Board on or near paper, plastic or cloth which  
could have a static charge. If the PC Board canʼt be  
installed immediately, put it back in the static-shielding  
bag.  
WARNING  
ELECTRIC SHOCK can kill.  
*Have an electrician install and service  
this equipment. Turn the machine  
OFF before working on equipment.  
Do not touch electrically hot parts.  
• If the PC Board uses protective shorting jumpers,  
donʼt remove them until installation is complete.  
• If you return a PC Board to The Lincoln Electric  
Company for credit, it must be in the static-shielding  
bag. This will prevent further damage and allow prop-  
er failure analysis.  
4. Test the machine to determine if the failure symp-  
tom has been corrected by the replacement PC  
Board.  
Sometimes machine failures appear to be due to PC  
Board failures. These problems can sometimes be  
traced to poor electrical connections. To avoid prob-  
lems when troubleshooting and replacing PC Boards,  
please use the following procedure:  
.......................................................................................  
1. Determine to the best of your technical ability that  
the PC Board is the most likely component causing  
the failure symptom.  
NOTE:  
It is desirable to have a spare (known good) PC  
Board available for PC Board troubleshooting.  
2. Check for loose connections at the PC Board to  
NOTE:  
Allow the machine to heat up so that all electri-  
assure that the PC Board is properly connected.  
cal components can reach their operating tem-  
perature.  
3. If the problem persists, replace the suspect PC  
Board using standard practices to avoid static elec-  
trical damage and electrical shock. Read the warn-  
ing inside the static resistant bag and perform the  
following procedures:  
5. Remove the replacement PC Board and substitute  
it with the original PC Board to recreate the original  
problem.  
a. If the original problem does not reappear  
by substituting the original board, then the  
PC Board was not the problem. Continue  
to look for bad connections in the control  
wiring harness, junction blocks, and termi-  
nal strips.  
b. If the original problem is recreated by the  
substitution of the original board, then the  
PC Board was the problem. Reinstall the  
replacement PC Board and test the  
machine.  
PC Board can be damaged by  
static electricity.  
• Remove your bodyʼs static charge  
before opening the static-shielding  
bag. Wear an anti-static wrist  
ATTENTION  
Static-Sensitive  
Devices  
strap. For safety, use a 1 Meg ohm  
resistive cord connected to a  
grounded part of the equipment  
frame.  
Handle only at  
Static-Safe  
• If you donʼt have a wrist strap,  
touch an unpainted, grounded,  
part of the equipment frame. Keep  
touching the frame to prevent stat-  
ic build-up. Be sure not to touch  
any electrically live parts at the  
same time.  
Workstations  
6. Always indicate that this procedure was followed  
when warranty reports are to be submitted.  
NOTE  
: Following this procedure and writing on the  
warranty  
report,  
“INSTALLED  
AND  
SWITCHED PC BOARDS TO VERIFY PROB-  
LEM,” will help avoid denial of legitimate PC  
Board warranty claims.  
• Tools which come in contact with the PC Board must  
be either conductive, anti-static or static-disipative.  
PRECISION TIG 275  
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F-4  
F-4  
TROUBLESHOOTING & REPAIR  
Observe Safety Guidelines  
TROUBLESHOOTING GUIDE  
detailed in the beginning of this manual.  
PROBLEMS  
POSSIBLE AREAS OF  
MISADJUSTMENT(S)  
RECOMMENDED  
(SYMPTOMS)  
COURSE OF ACTION  
OUTPUT PROBLEMS  
The machine is dead. No weld out- 1. Check the input voltage. The 1. Check the input power switch,  
put – no 115 VAC at the receptacle.  
input voltage must match the rat-  
ing plate and the voltage con-  
nection. Refer to Reconnect  
Procedure in the Installation  
section of this manual.  
reconnect panel and associated  
wires for loose or faulty connec-  
tions.  
2. The input power switch may be  
faulty.  
2. Make sure that the input power  
3. Perform the T1 Transformer  
switch is in the “ON” position.  
Test.  
3. Check for blown or missing  
fuses in the input lines.  
4. Check circuit breaker CB1.  
Reset if necessary.  
CAUTION  
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con-  
tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed.  
Call 1-888-935-3877.  
PRECISION TIG 275  
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F-5  
F-5  
TROUBLESHOOTING & REPAIR  
TROUBLESHOOTING GUIDE  
Observe Safety Guidelines  
detailed in the beginning of this manual.  
PROBLEMS  
POSSIBLE AREAS OF  
MISADJUSTMENT(S)  
RECOMMENDED  
(SYMPTOMS)  
COURSE OF ACTION  
OUTPUT PROBLEMS  
No welding output. The 115 VAC is 1. Make sure the polarity switch is 1. Check for loose or faulty connec-  
present at the receptacle.  
in the proper position and func-  
tioning correctly.  
tions on the heavy current carry-  
ing leads. ( Polarity switch, out-  
put choke, output terminals, etc.)  
2. One of the thermostats may be  
tripped. Allow the machine to  
cool. The thermal light will be 2. Check for faulty connections or a  
on.  
defective thermostat. Check  
leads #213 and #214. See the  
Wiring Diagram. The thermal  
light will be on.  
3. Make sure the welding cables,  
torch and connections are in  
good operating condition.  
NOTE: BEFORE REPLACING A  
CONTROL BOARD  
If an Advanced Control Panel is  
installed, remove it and replace  
the Jumper in connector J-3. If  
the machine functions normally,  
the Advanced Process panel or  
harness is defective.  
3. Perform the T1 Transformer  
Test.  
4. Perform the SCR Bridge Test.  
5. Check the output controls R1, R4  
and associated wiring. See  
Wiring Diagram.  
6. Check the J4 connection on the  
control board.  
7. The control board may be faulty.  
CAUTION  
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con-  
tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed.  
Call 1-888-935-3877.  
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
F-6  
F-6  
TROUBLESHOOTING & REPAIR  
Observe Safety Guidelines  
TROUBLESHOOTING GUIDE  
detailed in the beginning of this manual.  
PROBLEMS  
POSSIBLE AREAS OF  
MISADJUSTMENT(S)  
RECOMMENDED  
(SYMPTOMS)  
COURSE OF ACTION  
OUTPUT PROBLEMS  
No output from the machine in 1. The welding application may 1. One of the thermostats may be  
either Stick or TIG modes. The  
thermal light is on.  
have exceeded the recommend-  
ed duty cycle. Allow the fan to  
cool the until the thermal light is  
off.  
faulty. Check or replace. See  
the Wiring Diagram.  
2. Check for loose or faulty wires  
on the thermostats and associat-  
ed circuitry. See the Wiring  
Diagram.  
3. The fan motor may be faulty or  
mechanically obstructed. The  
fan should run when welding or  
when a thermostat is open.  
NOTE: BEFORE REPLACING A  
CONTROL BOARD  
2. The air louvers may be blocked.  
Remove the air obstruction and  
allow the unit to cool.  
If an Advanced Control Panel is  
installed, remove it and replace  
the Jumper in connector J-3. If  
the machine functions normally,  
the Advanced Process panel or  
harness is defective.  
4. The control board may be faulty.  
The machine does not respond (no 1. Make sure the machine is in the 1. Perform the Protection Board  
gas flow, no high frequency and no  
open circuit voltage) when the arc  
start switch or Amptrol is activated.  
The thermal light is not lit.  
TIG mode.  
Test.  
2. The Amptrol or arc start switch 2. Perform the T1 Transformer  
may be defective. Check for  
continuity ( zero ohms) between  
pins “D” and “E” on the cable  
connector when the Amptrol or  
arc start is pressed.  
Test.  
3. The control board may be faulty.  
NOTE: BEFORE REPLACING A  
CONTROL BOARD  
3. Check the Local/Remote switch  
If an Advanced Control Panel is  
installed, remove it and replace  
the Jumper in connector J-3. If  
the machine functions normally,  
the Advanced Process panel or  
harness is defective.  
for proper operation.  
CAUTION  
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con-  
tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed.  
Call 1-888-935-3877.  
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
F-7  
F-7  
TROUBLESHOOTING & REPAIR  
TROUBLESHOOTING GUIDE  
Observe Safety Guidelines  
detailed in the beginning of this manual.  
PROBLEMS  
POSSIBLE AREAS OF  
MISADJUSTMENT(S)  
RECOMMENDED  
(SYMPTOMS)  
COURSE OF ACTION  
OUTPUT PROBLEMS  
The machine does not have welding 1. Check the electrode cable and 1. Check the Stick/TIG switch and  
output in the Stick mode. The  
machine operates correctly in the  
TIG mode.  
SEE NOTE BELOW  
holder for loose or faulty connec-  
tions.  
associated leads. See the Wiring  
Diagram.  
2. Make sure the Stick/TIG switch is 2. The control board may be faulty.  
in the proper position and operat-  
ing correctly.  
The machine has welding output in 1. Make sure the Stick/TIG switch 1. Check the remote control recep-  
the Stick mode but no output in the  
TIG mode. ( no gas flow or high fre-  
quency).  
is in the proper position and  
operating correctly.  
tacle and associated wiring. See  
the Wiring Diagram.  
2. The remote control device may 2. Perform the Protection Board  
be faulty.  
Test.  
SEE NOTE BELOW  
3. Check the J11 plug on the con-  
trol board.  
Diagram.  
See the Wiring  
4. The control board may be faulty.  
The machine welds at a very low 1. If welding in the TIG mode, the 1. Check the polarity switch and  
output regardless of the current  
control setting.  
remote control device may be  
defective.  
2. Make certain the input line volt-  
age is correct for the machineʼs  
reconnect configuration.  
3. Check the welding cables and/  
or torch for loose or faulty con-  
nections.  
associated leads.  
2. Check the interior connections of  
the heavy current carrying leads.  
NOTE: BEFORE REPLACING A  
CONTROL BOARD  
3. Perform the SCR Bridge Test.  
4. Perform the T1 Transformer  
If an Advanced Control Panel is  
installed, remove it and replace  
the Jumper in connector J-3. If  
the machine functions normally,  
the Advanced Process panel or  
harness is defective.  
Test.  
5. Check the output current con-  
trols for proper operation.  
Normal resistance is 10,000  
ohms. See the Wiring Diagram.  
6. The control board may be faulty.  
CAUTION  
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con-  
tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed.  
Call 1-888-935-3877.  
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
F-8  
F-8  
TROUBLESHOOTING & REPAIR  
Observe Safety Guidelines  
TROUBLESHOOTING GUIDE  
detailed in the beginning of this manual.  
PROBLEMS  
POSSIBLE AREAS OF  
MISADJUSTMENT(S)  
RECOMMENDED  
(SYMPTOMS)  
COURSE OF ACTION  
OUTPUT PROBLEMS  
The machine welds at a very high 1. If welding in the TIG mode, the 1. Perform the SCR Bridge Test.  
output regardless of the current  
control setting.  
remote control device may be  
defective.  
2. Perform the T1 Transformer  
Test.  
3. Check the output current con-  
trols for proper operation.  
Normal resistance is 10,000  
ohms. See the Wiring Diagram.  
4. Check leads #221 and #222  
between the output shunt and  
the control board. See the  
Wiring Diagram.  
NOTE: BEFORE REPLACING A  
CONTROL BOARD  
If an Advanced Control Panel is  
installed, remove it and replace  
the Jumper in connector J-3. If  
the machine functions normally,  
the Advanced Process panel or  
harness is defective.  
5. The control board may be faulty  
Accessories plugged into the volt 1. Make sure the accessory plug 1. The circuit breaker (CB1) may be  
receptacle do not work.  
and associated leads are in good  
working condition.  
2. Make certain the correct input  
voltage is being applied to the  
machine. (The reconnect lead  
must be in the correct position.)  
faulty.  
2. Check the receptacle and asso-  
ciated leads for loose or faulty  
connections.  
3. Perform the T1 Transformer  
Test.  
3. The circuit breaker CB1 may be  
tripped. Reset if necessary.  
4. Only the top part of the recepta-  
cle is electronically “Hot” all of  
the time.  
CAUTION  
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con-  
tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed.  
Call 1-888-935-3877.  
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
F-9  
F-9  
TROUBLESHOOTING & REPAIR  
TROUBLESHOOTING GUIDE  
Observe Safety Guidelines  
detailed in the beginning of this manual.  
PROBLEMS  
POSSIBLE AREAS OF  
MISADJUSTMENT(S)  
RECOMMENDED  
(SYMPTOMS)  
COURSE OF ACTION  
OUTPUT PROBLEMS  
The machine makes a very loud 1. Inspect the output terminal insu- 1. Diode D1 may be shorted.  
buzzing noise in DC Stick or in DC  
TIG modes. There is no current  
draw from the machineʼs output ter-  
minals. (The machine is not exter-  
nally loaded).  
lators for cracks or signs of over-  
heating.  
Check and replace if necessary.  
2. Check the polarity switch (S2) for  
proper function and correct con-  
nections.  
3. Perform the SCR Bridge Tests.  
CAUTION  
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con-  
tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed.  
Call 1-888-935-3877.  
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
F-10  
F-10  
TROUBLESHOOTING & REPAIR  
Observe Safety Guidelines  
TROUBLESHOOTING GUIDE  
detailed in the beginning of this manual.  
PROBLEMS  
POSSIBLE AREAS OF  
MISADJUSTMENT(S)  
RECOMMENDED  
(SYMPTOMS)  
COURSE OF ACTION  
TIG WELDING PROBLEMS  
The machine output is intermittent- 1. The problem may be caused by 1. Check for loose or faulty con-  
ly lost. Gas flow and high frequen-  
cy are also interrupted.  
high frequency interference.  
Make sure that the machine is  
grounded properly according to  
the installation instructions. If  
there are other high frequency  
sources in the area, make cer-  
tain that they are grounded prop-  
erly.  
nections on the leads between  
the remote receptacle, the pro-  
tection board and plug J22 on  
the protection board. See the  
Wiring Diagram.  
NOTE: BEFORE REPLACING A  
CONTROL BOARD  
2. Check plugs J5 and J23 on the  
protection board for loose or  
faulty connections.  
If an Advanced Control Panel is  
installed, remove it and replace  
the Jumper in connector J-3. If  
2. Make sure the Amptrol is operat-  
3. Perform the Protection Board  
ing properly.  
Test.  
the machine functions normally, 3. Check to make sure that the  
4. The control board may be faulty.  
the Advanced Process panel or  
harness is defective.  
input voltage is correct for the  
machine. Refer to Reconnect 5. Check the ground connection of  
Procedure in the Installation  
the bypass/ stabilizer P.C.  
Board. See the Wiring Diagram.  
section of this manual.  
No gas or water flow (with option- 1. The gas (or water) supply is 1. Perform the Gas Solenoid Test.  
al water solenoid) when the arc  
start switch or Amptrol is activated  
in the TIG mode. All other ma-  
chine functions are normal.  
either empty or not turned on.  
2. The control board may be faulty.  
2. The low regulator may be set too  
low.  
3. Check the supply hoses for  
kinks or blockages.  
4. The filters may be blocked.  
CAUTION  
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con-  
tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed.  
Call 1-888-935-3877.  
PRECISION TIG 275  
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F-11  
F-11  
TROUBLESHOOTING & REPAIR  
TROUBLESHOOTING GUIDE  
Observe Safety Guidelines  
detailed in the beginning of this manual.  
PROBLEMS  
POSSIBLE AREAS OF  
MISADJUSTMENT(S)  
RECOMMENDED  
(SYMPTOMS)  
COURSE OF ACTION  
TIG WELDING PROBLEMS  
No high frequency. The machine is 1. If the machine is in a dirty envi- 1. Check the high voltage trans-  
in the TIG mode and has normal  
output.  
ronment with conductive contam-  
inants, check and clean the  
spark gap with a low pressure air  
stream per the maintenance  
instructions.  
former (T2). The normal resis-  
tance of the secondary winding is  
12.5k ohms.  
WARNING  
2. Check the spark gap operations  
and setting. Normal is (0.015”).  
Refer to the Maintenance  
Section of this manual.  
ELECTRIC SHOCK  
NOTE: BEFORE REPLACING A  
CONTROL BOARD  
CAN KILL. When  
115 VAC is applied  
If an Advanced Control Panel is  
installed, remove it and replace  
the Jumper in connector J-3. If  
to T2, a very high  
3. Check circuit breaker CB1.  
voltage is devel-  
Reset if necessary.  
oped on the secondary winding. For  
the machine functions normally, 4. Check connection J12 on the assistance, call the Lincoln Electric  
the Advanced Process panel or  
harness is defective.  
control board.  
Service Department. 1-888-935-  
3877.  
2. Check R5, C6, C7, L2 and L3.  
Replace if defective.  
3. The control board may be faulty.  
The High frequency is on continu- 1. None  
ously in DC TIG or shuts off in AC  
TIG.  
1. Check plug J11 on the control  
board. See the Wiring Diagram.  
2. Check micro-switch S2A for  
proper operation. See the Wiring  
Diagram.  
3. The control board may be faulty.  
CAUTION  
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con-  
tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed.  
Call 1-888-935-3877.  
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
F-12  
F-12  
TROUBLESHOOTING & REPAIR  
Observe Safety Guidelines  
TROUBLESHOOTING GUIDE  
detailed in the beginning of this manual.  
PROBLEMS  
POSSIBLE AREAS OF  
MISADJUSTMENT(S)  
RECOMMENDED  
(SYMPTOMS)  
COURSE OF ACTION  
TIG WELDING PROBLEMS  
High frequency “spark” is present 1. The spark gap may be too large. 1. The high voltage transformer  
but weak.  
Check and reset per instructions  
in the Maintenance Section of  
this manual.  
(T2) may be faulty.  
2. Capacitor C6 may be faulty.  
3. The high frequency transformer  
2. The work and/or torch cables  
may be in poor condition allow-  
ing the high frequency to “leak”  
to ground. Use good quality  
cables, preferably those with a  
high natural rubber content and  
as short as possible.  
(T3) may be faulty.  
3. If helium shielding gas is being  
used, reduce the percentage of  
helium.  
4. Make sure the tungsten elec-  
trode is the correct size for the  
process.  
Poor arc starting in the DC TIG 1. The input line voltage may be 1. Check the J11 plug on the con-  
mode. low. trol board. See Wiring Diagram.  
2. Check the torch and work cable 2. Check the background resistor  
for loose or faulty connections.  
R7. Normal resistance is 20  
ohms.  
3. Check the background diode  
bridge.  
CAUTION  
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con-  
tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed.  
Call 1-888-935-3877.  
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
F-13  
F-13  
TROUBLESHOOTING & REPAIR  
TROUBLESHOOTING GUIDE  
Observe Safety Guidelines  
detailed in the beginning of this manual.  
PROBLEMS  
POSSIBLE AREAS OF  
MISADJUSTMENT(S)  
RECOMMENDED  
(SYMPTOMS)  
COURSE OF ACTION  
TIG WELDING PROBLEMS  
The high frequency “spark” is pre- 1. The torch may be faulty. Check 1. Check spark gap adjustment.  
sent at the tungsten electrode, but  
the operator is unable to establish  
a welding arc. The machine has a  
normal open circuit voltage. Refer  
or replace.  
See the Maintenance Section.  
2. The current control may be set 2. This may be a welding proce-  
too low.  
dure problem. Contact the  
Lincoln Service Department,  
Technical Sales group at 1-888-  
935-3877.  
to Technical Specifications in the 3. The tungsten electrode may be  
Installation section.  
contaminated.  
sharpen.  
Replace or  
4. The electrode may be too large  
for the process.  
5. If a helium blend is being used  
as a shielding gas, reduce the  
percentage of helium.  
6. Check the welding cables for  
loose or faulty connections.  
When AC TIG welding, the arc is 1. The tungsten electrode may be 1. Check components R5 and C7 in  
erratic and there is a loss of “clean-  
ing” of the work piece.  
small for the process. Use a larg-  
er diameter tungsten or a pure  
tungsten.  
the high voltage transformer pri-  
mary circuit.  
2. Perform the SCR Bridge Test.  
2. If a helium blend is used as a  
shielding gas, reduce the per-  
centage of helium.  
3. Check the balance control set-  
ting.  
Arc “pulsates” in AC polarity. DC 1. Check that the machine controls 1. Micro switch S2A may be faulty.  
TIG is OK.  
are set correctly for the process.  
It should “open” in the AC mode.  
See the Wiring Diagram.  
CAUTION  
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con-  
tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed.  
Call 1-888-935-3877.  
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
F-14  
F-14  
TROUBLESHOOTING & REPAIR  
Observe Safety Guidelines  
TROUBLESHOOTING GUIDE  
detailed in the beginning of this manual.  
PROBLEMS  
POSSIBLE AREAS OF  
MISADJUSTMENT(S)  
RECOMMENDED  
(SYMPTOMS)  
COURSE OF ACTION  
STICK WELDING PROBLEMS  
The stick electrode “blasts-off” 1. Welding current may be too high 1. Perform the SCR Bridge Test.  
when touched to the work piece.  
for the electrode size. Reduce  
current control setting or use a  
larger diameter electrode.  
2. The control board may be faulty.  
NOTE: BEFORE REPLACING A  
CONTROL BOARD  
If an Advanced Control Panel is  
installed, remove it and replace  
the Jumper in connector J-3. If  
the machine functions normally,  
the Advanced Process panel or  
harness is defective.  
Variable or sluggish welding arc 1. Check the work and electrode 1. Check the polarity switch for  
when welding in the Stick mode.  
cables for loose or poor connec-  
tions.  
excessive wear or faulty connec-  
tions.  
2. The welding cables may be too 2. Check the interior heavy current  
small or too long to permit the  
desired current to flow.  
carrying leads and connections.  
3. The welding current may be set  
too low.  
CAUTION  
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con-  
tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed.  
Call 1-888-935-3877.  
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
F-15  
F-15  
TROUBLESHOOTING & REPAIR  
TROUBLESHOOTING GUIDE  
Observe Safety Guidelines  
detailed in the beginning of this manual.  
PROBLEMS  
POSSIBLE AREAS OF  
MISADJUSTMENT(S)  
RECOMMENDED  
(SYMPTOMS)  
COURSE OF ACTION  
FUNCTION PROBLEMS  
The meter does not display V (volt) 1. Check that either the advanced 1. Check R1 potentiometer and  
or minimum current.  
control board or jumper plug is in  
J3 on the control board.  
associated leads between the  
control board and plug J9. See  
the Wiring Diagram.  
2. The control board may be faulty.  
NOTE: BEFORE REPLACING A  
CONTROL BOARD  
If an Advanced Control Panel is  
installed, remove it and replace  
the Jumper in connector J-3. If  
the machine functions normally,  
the Advanced Process panel or  
harness is defective.  
CAUTION  
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con-  
tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed.  
Call 1-888-935-3877.  
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
F-16  
F-16  
TROUBLESHOOTING & REPAIR  
TROUBLESHOOTING GUIDE  
Observe Safety Guidelines  
detailed in the beginning of this manual.  
PROBLEMS  
POSSIBLE AREAS OF  
MISADJUSTMENT(S)  
RECOMMENDED  
(SYMPTOMS)  
COURSE OF ACTION  
FUNCTION PROBLEMS  
The AC wave balance control does 1. The AC wave balance control is 1. Check the AC balance control  
not function properly.  
operational only in the TIG mode.  
(R2) and associated leads for  
loose or faulty connections. See  
the Wiring Diagram.  
2. The control board may be faulty.  
NOTE: BEFORE REPLACING A  
CONTROL BOARD  
If an Advanced Control Panel is  
installed, remove it and replace  
the Jumper in connector J-3. If  
the machine functions normally,  
the Advanced Process panel or  
harness is defective.  
Gas pre-flow and post-flow time is 1. If an advanced control board is 1. Check plug J3 on the control  
too long.  
installed, check dip switch set-  
board. Either the jumper plug or  
the advanced control board must  
be plugged into J3.  
ting on the board.  
See  
Installation Manual.  
CAUTION  
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con-  
tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed.  
Call 1-888-935-3877.  
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
F-17  
F-17  
TROUBLESHOOTING & REPAIR  
Observe Safety Guidelines  
TROUBLESHOOTING GUIDE  
detailed in the beginning of this manual.  
PROBLEMS  
POSSIBLE AREAS OF  
MISADJUSTMENT(S)  
RECOMMENDED  
(SYMPTOMS)  
COURSE OF ACTION  
FUNCTION PROBLEMS  
The meter does not display V (volt) 1. Toggle the display switch. It may 1. Check the leads between the  
or minimum current.  
be dirty.  
display switch and the control  
board. See the Wiring Diagram.  
2. The display switch may be faulty.  
3. The control board may be faulty.  
NOTE: BEFORE REPLACING A  
CONTROL BOARD  
If an Advanced Control Panel is  
installed, remove it and replace  
the Jumper in connector J-3. If  
the machine functions normally,  
the Advanced Process panel or  
harness is defective.  
The meter does not light up. Other 1. None  
machine functions are OK.  
1. Check the leads and connec-  
tions between the meter and the  
control board. See the Wiring  
Diagram.  
2. The meter may be faulty.  
3. The control board may be faulty.  
NOTE: BEFORE REPLACING A  
CONTROL BOARD  
If an Advanced Control Panel is  
installed, remove it and replace  
the Jumper in connector J-3. If  
the machine functions normally,  
the Advanced Process panel or  
harness is defective.  
CAUTION  
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con-  
tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed.  
Call 1-888-935-3877.  
PRECISION TIG 275  
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F-18  
F-18  
NOTES  
PRECISION TIG 275  
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F-19  
F-19  
TROUBLESHOOTING & REPAIR  
METER CALIBRATION ADJUSTMENTS  
WARNING  
Service and repair should be performed by only Lincoln Electric factory trained personnel.  
Unauthorized repairs performed on this equipment may result in danger to the technician  
or machine operator and will invalidate your factory warranty. For your safety and to avoid  
electrical shock, please observe all safety notes and precautions detailed throughout this  
manual.  
If for any reason you do not understand the test procedures or are unable to perform the  
test/repairs safely, contact the Lincoln Electric Service Department for electrical trou-  
bleshooting assistance before you proceed. Call 1-888-935-3877.  
DESCRIPTION  
This test will help aid the technician in meter circuits calibration.  
MATERIALS NEEDED  
Voltmeter/Ohmmeter  
3/8” Nut Driver  
Wiring Diagram  
PRECISION TIG 275  
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F-20  
F-20  
TROUBLESHOOTING & REPAIR  
METER CALIBRATION ADJUSTMENTS (continued)  
FIGURE F.1 – TRIMMER  
306  
301  
TRIMMER  
303  
304B  
302  
JUMPER  
Note: The Precision TIG meter circuits are factory calibrated for the accuracy of the ammeter and voltmeter and  
should not need adjustment. However, the factory trimmers are accessible inside the control box:  
CALIBRATION CHECK  
The Digital Meter Calibration Trimmer is located on the  
back of the meter housing near the right side connec-  
tor plug (with two leads and a jumper attached). This  
trimmer adjusts calibration of the meter used for both  
ammeter and voltmeter readings, so its calibration  
should be checked first, as follows:  
1. Set the TIG mode and, without closing the arc start  
switch, preset the panel maximum output control so  
the panel digital meter reads 200 amps.  
2. Using a DC (avg.) digital test voltmeter with at least  
0.5% accuracy at 1,000v, measure the DC voltage  
between (+) pin 2 (lead #303) and (-) pin 1 (lead  
#306) at the right side meter plug (nearest the trim-  
mer).  
3. This voltage should match the 200A panel meter  
reading (as 0.200v, or 200mv) within 1%. If not,  
adjust the trimmer so that the panel meter accuracy  
is corrected. (See Figure F.1)  
PRECISION TIG 275  
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F-21  
F-21  
TROUBLESHOOTING & REPAIR  
METER CALIBRATION ADJUSTMENTS (continued)  
FIGURE F.2 - CONTROL BOARD TRIMMERS  
R-2  
C3  
R10  
C5  
R27  
D2  
R12  
R33  
C4  
Q9  
DZ24  
D10  
R2  
R28  
R29  
C13  
X3  
R40  
R41  
C18  
C19  
R11  
D6  
R30  
R31  
R32  
R66  
R34  
R35  
R36  
R68  
R69  
R70  
R71  
C20  
R77  
Q8  
R73  
C15  
D11  
D22  
R42  
R79  
D7  
C14  
Q14  
R60  
R74  
R78  
DZ22  
D23  
R62  
R63  
C34  
C35  
R107  
R80  
D19  
DZ4  
DZ25  
C31  
R64  
R65  
R67  
C32  
R72  
D21  
R75  
R76  
R61  
R81  
D20  
C28  
C29  
C30  
R82  
D24  
Q16  
C44  
R91  
C45  
C48  
D31  
C36  
Q21  
R105  
R106  
C49  
R101  
R102  
D34  
C47  
R95  
R96  
R93  
R94  
R99  
Q17  
Q18  
R97  
R98  
R100  
R359  
R103  
D30  
C63  
C64  
R120  
R104  
C58  
C46  
R132  
R133  
R130  
R131  
R129  
R3  
R121  
R92  
C55  
R126  
R127  
R122  
C60  
C62  
R135  
Q20  
X
X
X
X
X
X
X
X
X
X
X
X
X
X
D41  
R119  
DZ6  
C56  
R125  
R167  
D42  
R123  
R124  
R163  
R164  
C72  
R134  
R175  
C59  
Q19  
C61  
R361  
DZ21  
D58  
R136  
C77  
R128  
C74  
C76  
D54  
R168  
R169  
C73  
R161  
R162  
C70  
R176  
R211  
C92  
R205  
R170  
C75  
R173  
R174  
R208  
C91  
R203  
R165  
R166  
X
X
X
X
X
X
X
X
X
X
C71  
D62  
D59  
D64  
R358  
C165  
D55  
R212  
R204  
C87  
D89  
R202  
D63  
R209  
R210  
C93  
C89  
C90  
C85  
Q23  
Q26  
D65  
C86  
C88  
104  
R4  
R357  
C105  
R257  
R258  
R259  
R246  
R247  
C106  
DZ10  
C123  
R252  
C103  
C
DZ9  
C109  
C110  
Q25  
X X  
R248  
R251  
C108  
R291  
R254  
R244  
Q27  
R245  
R270  
R271  
R272  
R273  
C119  
R311  
D67  
C102  
R269  
R249  
C107  
C125  
R255  
R253  
R292  
C126  
C127  
R275  
R276  
C120  
OCI6  
R6  
R293  
R336  
C151  
R277  
R278  
R279  
R315  
R316  
R317  
R318  
R321  
XXX  
R-5  
R274  
R312  
C144  
R313  
C156  
OCI7  
DZ17  
XXX  
D81  
D82  
C141  
R351  
C143  
R314  
R335  
C150  
D83  
C158  
C157  
R352  
R353  
R7  
X
X
X
J8  
X X X X  
X X X X  
X X X X  
J5A  
X X  
J6  
X
X
X
C159  
J9  
J10  
J7  
X
X X X X  
X X  
X
X X X X X X  
X X X X X X  
AMMETER CALIBRATION PROCEDURE  
VOLTMETER CALIBRATION PROCEDURE  
1. Locate the Ammeter Calibration Trimmer (R5). See  
Figure F.1.  
1. Locate the Voltmeter Calibration Trimmer (R2) on  
the control board. See Figure F1.  
2. Set to TIG mode with DC polarity and LOCAL con-  
trol. Without closing the arc start switch, preset the  
maximum output panel control so the panel digital  
meter reads approx. 200 amps.  
3. Using a DC (AVG.) test ammeter with at least 1%  
accuracy at up to 300 amps, connect it to measure  
the DC current through a short weld cable shorting  
out the work(+) to electrode(-) studs on the front stud  
panel. Remove the TIG torch if connected.  
2. To prevent maximum OCV output, disconnect the  
SCR gate lead plug from receptacle J4.  
3. Set to TIG mode with DC- polarity without closing the  
arc start switch.  
4. Using a DC (avg.) test voltmeter with at least 1%  
accuracy at up to 100 volts, connect it across the  
work (+) and electrode (-) studs on the front stud  
panel. Remove the TIG torch, if connected.  
4. Close the arc start switch just long enough to com-  
pare the panel meter reading to that of the test  
ammeter. The short circuit current readings should  
match within 4% +/-2A. If not, adjust the trimmer so  
that the panel meter accuracy is corrected.  
5. Press the display panel switch to V (volts) position,  
then close the arc start switch just long enough to  
compare the panel meter reading to that of the test  
volt meter. The open circuit voltage readings (about  
50 VDC) should match within 3% +/-1v. If not, adjust  
the trimmer so that the panel meter accuracy is cor-  
rected.  
NOTE: If the Arc Start switch is held closed longer than  
about 15 seconds, the machine will shut down  
to protect internal holding resistor from over-  
heating.  
PRECISION TIG 275  
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F-22  
F-22  
NOTES  
PRECISION TIG 275  
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F-23  
F-23  
TROUBLESHOOTING & REPAIR  
HIGH FREQUENCY CIRCUIT DISABLE PROCEDURE  
WARNING  
Service and repair should be performed by only Lincoln Electric factory trained personnel.  
Unauthorized repairs performed on this equipment may result in danger to the technician  
or machine operator and will invalidate your factory warranty. For your safety and to avoid  
electrical shock, please observe all safety notes and precautions detailed throughout this  
manual.  
If for any reason you do not understand the test procedures or are unable to perform the  
test/repairs safely, contact the Lincoln Electric Service Department for electrical trou-  
bleshooting assistance before you proceed. Call 1-888-935-3877.  
DESCRIPTION  
This procedure will disable the high frequency circuit allowing the technician to take volt-  
age measurements without the possibility of high frequency damage to his test equipment.  
MATERIALS NEEDED  
3/8” Nut Driver  
Electrical Insulating Tape  
PRECISION TIG 275  
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F-24  
F-24  
TROUBLESHOOTING & REPAIR  
HIGH FREQUENCY CIRCUIT DISABLE PROCEDURE (continued)  
FIGURE F.2 – SPARK GAP ASSEMBLY  
VIEWED FROM ABOVE  
LEADS  
ATTACH  
HERE  
.015 Spark Gap  
M
O
D
E
M
IN  
IM  
U
M
D
IS  
P
L
A
Y
L
O
C
A
L
A
C
B
A
R
L
A
E
M
N
C
O
T
E
E
!
W
A
R
N
IN  
G
M
A
X
IM  
U
M
O
N
P
O
W
E
R
D
O
A
F
C
F
C
P
O
~
S
T
F
L
O
W
S
Q
U
A
R
f
E
e
a
W
A
t
L
u
r
V
E
in  
I
N
E
g
P
I
..  
O
W
.
M
C
L
E
R
O
E
C
S
O
O
L
R
U
R
N
T
D
C
SE  
C
C
+
T
R
A
E
C
I
T
C
R
H
T
TM  
N
O
L
O
G
P
Y
D
O
H
W
N
R
O
T
W
IL  
S
E
E
W
L
IT  
D
E
C
H
G
IN  
C
I
S
I
O
N
T
I
T
M
G
T
H
E
L
IN  
C
O
3
7
R
O
M
L
N
E
L
E
C
T
IC  
5
C
V
E
L
C
P
A
N
Y
L
E
A
N
D
,
O
H
IO  
U
S
A
PROCEDURE  
6. When voltage testing and scope measure-  
ments are complete, reconnect the three  
leads to the Spark Gap Assembly.  
7. Reassemble the right side case cover.  
1. Remove the input power to the PRECISION  
TIG 275 machine.  
2. Using the 3/8” nut driver, remove the right  
side case cover.  
3. Locate the Spark Gap Assembly at the lower  
rear right side of the machine. See Figure  
F.2.  
4. Carefully remove the three leads from the  
Spark Gap Assembly. See Figure F.2.  
5. Insulate the leads from each other and from  
the case.  
PRECISION TIG 275  
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F-25  
F-25  
TROUBLESHOOTING & REPAIR  
PROTECTION BOARD TEST  
WARNING  
Service and repair should be performed by only Lincoln Electric factory trained personnel.  
Unauthorized repairs performed on this equipment may result in danger to the technician  
or machine operator and will invalidate your factory warranty. For your safety and to avoid  
electrical shock, please observe all safety notes and precautions detailed throughout this  
manual.  
If for any reason you do not understand the test procedures or are unable to perform the  
test/repairs safely, contact the Lincoln Electric Service Department for electrical trou-  
bleshooting assistance before you proceed. Call 1-888-935-3877.  
TEST DESCRIPTION  
This procedure will determine if the Protection board is functioning properly.  
MATERIALS NEEDED  
3/8” Nut Driver  
Voltmeter/Ohmmeter (Multimeter)  
Tig 275 Wiring Diagrams  
PRECISION TIG 275  
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F-26  
F-26  
TROUBLESHOOTING & REPAIR  
PROTECTION BOARD TEST (continued)  
1. Using a 3/8” nut driver, remove the case top  
3. Unplug P5 from the control board. Measure  
resistance at P5. See Figure F3. See tables  
below.  
and sides.  
2. Check that P5 is connected to J5, not J5A.  
See the Wiring Diagram.  
Table F.1  
RESISTANCE BETWEEN  
READING  
Pins 5 & 7  
TRIGGER  
B-C  
Open when trigger open, short when trigger closed.  
Increasing from 0 to 10K when working on remote  
Pins 3 & 4  
amptrol from min. to max.  
Decreasing from 10K to 0 when working on remote  
amptrol from min. to max.  
B-A  
Pins 2 & 3  
4. If the readings above are OK, the protection  
board is OK. If not, go to step 5.  
7. If readings below are OK, protection board  
is bad.  
5. Unplug P23 from the protection board and  
check continuity from P23 to P5. If OK, go  
to step 6. See Wiring Diagram.  
8. If readings below are wrong, remote amptrol  
or remote receptacle is bad.  
6. Unplug P22 from protection board. Measure  
resistance at P22. See Tables.  
Table F.2  
RESISTANCE BETWEEN  
READING  
Pins 3 & 6  
TRIGGER  
B-C  
Open when trigger open, short when trigger closed.  
Increasing from 0 to 10K when working on remote  
Pins 1 & 2  
amptrol from min. to max.  
Decreasing from 10K to 0 when working on remote  
amptrol from min. to max.  
B-A  
Pins 1 & 4  
FIGURE F.3 – Plug J5 (viewed from pin end)  
2
7
4
5
3
6
1
8
Jumper  
PRECISION TIG 275  
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F-27  
F-27  
TROUBLESHOOTING & REPAIR  
T1 MAIN TRANSFORMER TEST  
WARNING  
Service and repair should be performed by only Lincoln Electric factory trained personnel.  
Unauthorized repairs performed on this equipment may result in danger to the technician  
or machine operator and will invalidate your factory warranty. For your safety and to avoid  
electrical shock, please observe all safety notes and precautions detailed throughout this  
manual.  
If for any reason you do not understand the test procedures or are unable to perform the  
test/repairs safely, contact the Lincoln Electric Service Department for electrical trou-  
bleshooting assistance before you proceed. Call 1-888-935-3877.  
DESCRIPTION  
This procedure will determine if the correct voltage is being applied to the primary of the  
T1 transformer and also if the correct voltages are being induced on the secondary wind-  
ings of the transformer.  
MATERIALS NEEDED  
3/8” Nut Driver  
Voltmeter/Ohmmeter (Multimeter)  
Tig 275 Wiring Diagrams  
PRECISION TIG 275  
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F-28  
F-28  
TROUBLESHOOTING & REPAIR  
T1 MAIN TRANSFORMER TEST (continued)  
Figure F.4 Plug J11  
G3909  
263  
214  
204  
210  
266  
220  
270  
253  
Plug  
J11  
Plug  
J11  
209  
201  
265  
262  
252  
269  
271  
213  
TEST PROCEDURES  
1. Using the 3/8” nut driver, remove the two screws  
from the front control panel. Carefully lower the  
panel. This will allow access to the control board.  
5. Carefully check for 63.5 VAC at leads 267 to lead  
268. Lead 268 is located at the background rectifi-  
er.  
Note: Lead 267 is located at resistor R8. See Wiring  
2. Locate plug J11 on the control board. See Figure  
Diagram.  
F.4.  
6. Carefully check for 115 VAC at leads 231 to 232.  
WARNING  
Note: Lead 231 is located at the 115 VAC recepta-  
cle on the back of the machine. Lead 232 is  
located at the 15 amp circuit breaker CB1.  
ELECTRIC SHOCK can kill.  
*With input power ON, there are high voltages inside  
the machine. Do not reach  
7. If all of the secondary voltages are correct, the T1  
transformer is functioning properly.  
into the machine or touch any  
internal part.  
a. If all of the secondary voltages are missing or  
incorrect, make certain that the correct input  
voltage is being applied to the correct primary  
leads. See Table F.3.  
...........................................................................  
3. Carefully apply the correct input power making cer-  
tain the reconnect configuration at the reconnect  
panel is correct for the input voltage applied. Turn  
the Precision TIG 275 ON.  
b. If the correct input voltage is being applied to  
the primary leads and any or all of the sec-  
ondary voltages are incorrect, the T1 trans-  
former may be faulty. Also check the leads for  
broken or loose connections between plug J11  
and the T1 transformer.  
4. Using the voltmeter, carefully test for the correct  
transformer secondary voltages per Table F.3.  
8. Replace the case side covers.  
PRECISION TIG 275  
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F-29  
F-29  
TROUBLESHOOTING & REPAIR  
T1 MAIN TRANSFORMER TEST (continued)  
Table F.3 - T1 Transformer Voltages  
TEST POINTS  
ACCEPTABLE VOLTAGES  
SECONDARY WINDINGS  
SECONDARY VOLTAGES  
PLUG J11 PIN 8 (LEAD W209)  
TO  
PLUG J11 PIN 16 (LEAD R210)  
20 VAC  
PLUG J11 PIN 7 (LEAD #201)  
TO  
18VAC  
78 VAC  
PLUG J11 PIN 15 (LEAD #204)  
X1 TO X2  
PRIMARY WINDINGS  
H1 TO H2  
PRIMARY VOLTAGES  
208 VAC  
H1 TO H3  
230 VAC  
H1 TO H4  
460 VAC  
NOTE: If the input voltages vary, the secondary voltages will vary accordingly.  
Based on 208/230/460 models. For other voltage models refer to appropriate Wiring Diagram.  
PRECISION TIG 275  
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F-30  
F-30  
NOTES  
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F-31  
F-31  
TROUBLESHOOTING & REPAIR  
GAS (WATER) SOLENOID TEST  
WARNING  
Service and repair should be performed by only Lincoln Electric factory trained personnel.  
Unauthorized repairs performed on this equipment may result in danger to the technician  
or machine operator and will invalidate your factory warranty. For your safety and to avoid  
electrical shock, please observe all safety notes and precautions detailed throughout this  
manual.  
If for any reason you do not understand the test procedures or are unable to perform the  
test/repairs safely, contact the Lincoln Electric Service Department for electrical trou-  
bleshooting assistance before you proceed. Call 1-888-935-3877.  
TEST DESCRIPTION  
This procedure will help the technician to determine if the solenoid is receiving the correct  
voltage also if the solenoid is functional.  
MATERIALS NEEDED  
3/8” Nut Driver  
Voltmeter/Ohmmeter (Multimeter)  
Isolated 115 VAC Power Supply  
PRECISION TIG 275  
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F-32  
F-32  
TROUBLESHOOTING & REPAIR  
GAS (WATER) SOLENOID TEST (continued)  
TEST PROCEDURE  
7. Activate the torch trigger and check for  
approximately 115 VAC at the solenoid leads  
(#231A and # 235). If the correct voltage is  
present, the solenoid should activate and  
gas should flow.  
8. If voltage is present at leads #231A and  
#235 and the solenoid does not activate, the  
solenoid may be defective. The solenoid  
can be further checked by removing leads  
#231A and #235 from the solenoid and  
applying the external isolated 115 VAC sup-  
ply to the solenoid terminals. If the solenoid  
activates with the external supply but not  
when powered by the control board, the  
problem may be in the control board. If you  
hear solenoid activation but there is still no  
gas flow, check for restrictions in the line.  
1. Remove input power to the Precision TIG  
275 machine.  
2. Remove the left case side.  
3. Perform the High Frequency Circuit  
Disable Procedure.  
4. Locate the gas solenoid in the torch connec-  
tion box.  
5. Put the mode switch S3 in the 2-Step TIG  
position.  
WARNING  
ELECTRIC SHOCK CAN  
KILL.  
*With input power ON, there  
are high voltages inside the  
machine. Do not reach into  
the machine or touch any  
internal part.  
9. When the test is complete, replace leads  
#231A and #235.  
10. Reassemble the two leads previously  
removed in the High Frequency Circuit  
Disable Procedure.  
11. Reassemble the left case side.  
12. If a water solenoid is used, it can be tested  
6. Apply the correct input power to the TIG 275.  
using the same procedures.  
PRECISION TIG 275  
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F-33  
F-33  
TROUBLESHOOTING & REPAIR  
STATIC SCR TEST  
WARNING  
Service and repair should be performed by only Lincoln Electric factory trained personnel.  
Unauthorized repairs performed on this equipment may result in danger to the technician  
or machine operator and will invalidate your factory warranty. For your safety and to avoid  
electrical shock, please observe all safety notes and precautions detailed throughout this  
manual.  
If for any reason you do not understand the test procedures or are unable to perform the  
test/repairs safely, contact the Lincoln Electric Service Department for electrical trou-  
bleshooting assistance before you proceed. Call 1-888-935-3877.  
DESCRIPTION  
The SCR test is a quick check to determine if an SCR is “shorted” or “leaky”. See machine  
waveform section for normal and abnormal SCR waveforms.  
MATERIALS NEEDED  
3/8” Nut Driver  
Analog Ohmmeter (Multimeter)  
Tig 275 Wiring Diagrams  
SCR Heatsink Assembly Drawing  
PRECISION TIG 275  
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F-34  
F-34  
TROUBLESHOOTING & REPAIR  
STATIC SCR TEST (continued)  
Figure F.5 - Plug J4 Location  
G3909  
Plug  
J4  
Removal and Replacement.  
TEST PROCEDURE  
1. Remove main supply power to the PRECI-  
SION TIG 275 and remove the case top and  
left side.  
4. Repeat Step #3 testing SCR2, SCR3 and  
SCR4.  
5. To further check the SCRʼs functions, use an  
SCR tester and proceed to the Active SCR  
Test.  
2. Locate and remove plug J4 from the control  
board. See Figure F.5.  
3. Using an analog ohmmeter, test the resis-  
tance from anode to cathode of SCR1.  
Reverse the meter leads and check from  
cathode to anode of SCR1. See Figure F.5. If  
a low resistance is indicated in either direc-  
tion, SCR1 is faulty. Replace the SCR Bridge  
Assembly. See SCR Bridge Assembly  
NOTE: Also check diode D1.  
6. Replace plug J4 on the control board.  
7. Replace the case top and left side.  
Figure F.6 - SCR TEST POINTS  
LIFT BAIL STABILIZER  
DIODE D1  
SCR1 ANODE  
SCR4 CATHODE  
SCR1 / SCR2 CATHODE  
SCR3 CATHODE  
SCR2 ANODE  
SCR3 / SCR4 ANODE  
PRECISION TIG 275  
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TROUBLESHOOTING & REPAIR  
F-35  
F-35  
ACTIVE SCR TEST  
WARNING  
Service and repair should be performed by only Lincoln Electric factory trained personnel.  
Unauthorized repairs performed on this equipment may result in danger to the technician  
or machine operator and will invalidate your factory warranty. For your safety and to avoid  
electrical shock, please observe all safety notes and precautions detailed throughout this  
manual.  
If for any reason you do not understand the test procedures or are unable to perform the  
test/repairs safely, contact the Lincoln Electric Service Department for electrical trou-  
bleshooting assistance before you proceed. Call 1-888-935-3877.  
DESCRIPTION  
The Active SCR test will determine if the device is able to be gated “ON” and conduct cur-  
rent from anode to cathode.  
MATERIALS NEEDED  
3/8” Nut Driver  
TIG 275 Wiring Diagrams  
An SCR Tester as Outlined in this Procedure  
PRECISION TIG 275  
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F-36  
F-36  
TROUBLESHOOTING & REPAIR  
ACTIVE SCR TEST (continued)  
Figure F.7 - Plug J4 Location  
G3909  
Plug  
J4  
4. Construct the circuit outline in Figure F.8.  
One 6V lantern battery can be used. Resistor  
values are +\- 10%. The voltmeter scale  
should be approximately 0-5 or 0-10 volts.  
5. Battery Test - Check the battery by shorting  
leads (A) and (C) and then close switch SW-  
1. Replace the battery if voltage is less than  
4.5 volts.  
TEST PROCEDURE  
1. Remove main supply power to the PRECI-  
SION TIG 275 machine.  
2. Locate and remove plug J4 from the control  
board. See Figure F.7.  
3. Perform the following test for all four SCRs.  
See Figure F.8.  
PRECISION TIG 275  
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F-37  
F-37  
TROUBLESHOOTING & REPAIR  
ACTIVE SCR TEST (continued)  
Figure F.8 - Active SCR Test Set-Up  
R2  
SW1  
+
R1  
SW2  
V
6 volt  
lantern  
battery  
A
G
SCR  
under  
test  
C
R1 = 4 ohms / 10 watts  
R2 = 3 ohms / 10 watts  
Resistor values are +/- 10%  
PRECISION TIG 275  
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F-38  
F-38  
TROUBLESHOOTING & REPAIR  
ACTIVE SCR TEST (continued)  
Figure F.9 - SCR Gate Locations  
LIFT BAIL STABILIZER  
DIODE D1  
SCR1 ANODE  
SCR4 CATHODE  
SCR1 / SCR2 CATHODE  
SCR3 CATHODE  
SCR3 / SCR4 ANODE  
SCR2 ANODE  
6. Connect SCR into the test circuit as shown  
in Figure F.8. (A)Lead to anode (C) lead to  
cathode and (G) lead to the gate.  
7. Close switch SW-1 (Switch SW-2 should be  
open). The voltmeter should read zero. If  
the voltmeter reads higher than zero, the  
SCR is shorted.  
8. With switch SW-1 closed, close switch SW-2  
for two seconds and release. The voltmeter  
should read 3 to 6 volts before and after  
switch SW-2 is released. If the voltmeter  
does not read, or reads only while SW-2 is  
depressed, the SCR or battery is defective.  
(Repeat Battery Test Procedure described in  
Step 5.)  
9. Open switch SW-1, disconnect the gate lead  
(G) and reverse the (A) and (C) leads on  
the SCR. Close switch SW-1. The voltmeter  
should read zero. If the voltage is higher  
than zero, the SCR is shorted.  
10. Replace any SCRs that do not pass the  
test. See SCR Bridge Assembly  
Removal and Replacement.  
11. Replace plug J4 on the control board.  
12. Replace the case sides and top.  
PRECISION TIG 275  
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F-39  
F-39  
TROUBLESHOOTING & REPAIR  
TYPICAL OUTPUT VOLTAGE WAVEFORM - MACHINE LOADED TO 2 AMPS  
DC - TIG MODE  
HIGH VOLTAGE/ HIGH FREQUENCY can damage test equipment.  
Perform all voltage and waveform checks with high frequency circuit OFF.  
Perform High Frequency Disable Procedure.  
0V  
20V  
5 ms  
AC BALANCE CONTROL IN “AUTO”  
OUTPUT CONTROL AT MINIMUM  
This is the typical AC output voltage  
waveform generated from a properly  
operating machine. Note that each ver-  
tical division represents 20 volts and  
that each horizontal division represents  
5 milliseconds in time.  
NOTE: Scope probes connected at  
machine output terminals: (+) probe to  
electrode, (-) probe to work.  
SCOPE SETTINGS  
Volts/Div......................20V/Div.  
Horizontal Sweep......5 ms/Div.  
Coupling..............................DC  
Trigger..........................Internal  
PRECISION TIG 275  
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F-40  
F-40  
TROUBLESHOOTING & REPAIR  
TYPICAL OUTPUT VOLTAGE WAVEFORM - MACHINE LOADED TO 200 AMPS  
AC - TIG MODE  
HIGH VOLTAGE/ HIGH FREQUENCY can damage test equipment.  
Perform all voltage and waveform checks with high frequency circuit OFF.  
Perform High Frequency Disable Procedure.  
0V  
20V  
5 ms  
AC BALANCE CONTROL IN “AUTO”  
This is the typical AC output voltage  
waveform generated from a properly  
operating machine. Note that each ver-  
tical division represents 20 volts and  
that each horizontal division represents  
5 milliseconds in time. The machine  
was loaded with a resistance grid bank.  
NOTE: Scope probes connected at  
machine output terminals: (+) probe to  
electrode, (-) probe to work.  
SCOPE SETTINGS  
Volts/Div......................20V/Div.  
Horizontal Sweep......5 ms/Div.  
Coupling..............................DC  
Trigger..........................Internal  
PRECISION TIG 275  
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F-41  
F-41  
TROUBLESHOOTING & REPAIR  
TYPICAL AC VOLTAGE WAVEFORM - MACHINE LOADED TO 50 AMPS  
AC - TIG MODE  
HIGH VOLTAGE/ HIGH FREQUENCY can damage test equipment.  
Perform all voltage and waveform checks with high frequency circuit OFF.  
Perform High Frequency Disable Procedure.  
0V  
20V  
5 ms  
AC BALANCE CONTROL IN “AUTO”  
This is the typical DC (+) output voltage  
waveform generated from a properly  
operating machine. Note that each ver-  
tical division represents 20 volts and  
that each horizontal division represents  
5 milliseconds in time.  
NOTE: Scope probes connected at  
machine output terminals: (+) probe to  
electrode, (-) probe to work.  
SCOPE SETTINGS  
Volts/Div......................20V/Div.  
Horizontal Sweep......5 ms/Div.  
Coupling..............................DC  
Trigger..........................Internal  
PRECISION TIG 275  
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F-42  
F-42  
TROUBLESHOOTING & REPAIR  
TYPICAL AC VOLTAGE WAVEFORM - MACHINE LOADED TO 2 AMPS  
AC - TIG MODE  
HIGH VOLTAGE/ HIGH FREQUENCY can damage test equipment.  
Perform all voltage and waveform checks with high frequency circuit OFF.  
Perform High Frequency Disable Procedure.  
0V  
20V  
5 ms  
AC BALANCE CONTROL IN “AUTO”  
OUTPUT CONTROL AT MINIMUM.  
This is the typical AC output voltage  
waveform generated from a properly  
operating machine. Note that each ver-  
tical division represents 20 volts and  
that each horizontal division represents  
5 milliseconds in time.  
NOTE: Scope probes connected at  
machine output terminals: (+) probe to  
electrode, (-) probe to work.  
SCOPE SETTINGS  
Volts/Div......................20V/Div.  
Horizontal Sweep......5 ms/Div.  
Coupling..............................DC  
Trigger..........................Internal  
PRECISION TIG 275  
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F-43  
F-43  
TROUBLESHOOTING & REPAIR  
TYPICAL OUTPUT VOLTAGE WAVEFORM - MACHINE LOADED TO 200 AMPS  
DC - TIG MODE  
HIGH VOLTAGE/ HIGH FREQUENCY can damage test equipment.  
Perform all voltage and waveform checks with high frequency circuit OFF.  
Perform High Frequency Disable Procedure.  
0V  
20V  
5 ms  
This is the typical AC output voltage  
waveform generated from a properly  
operating machine. Note that each ver-  
tical division represents 20 volts and  
that each horizontal division represents  
5 milliseconds in time.  
NOTE: Scope probes connected at  
machine output terminals: (+) probe to  
electrode, (-) probe to work.  
NOTE: AC balance control set at  
“Balanced” position.  
SCOPE SETTINGS  
Volts/Div......................20V/Div.  
Horizontal Sweep......5 ms/Div.  
Coupling..............................DC  
Trigger..........................Internal  
PRECISION TIG 275  
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F-44  
F-44  
NOTES  
PRECISION TIG 275  
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F-45  
F-45  
TROUBLESHOOTING & REPAIR  
HIGH VOLTAGE TRANSFORMER REMOVAL AND REPLACEMENT  
WARNING  
Service and repair should be performed by only Lincoln Electric factory trained personnel.  
Unauthorized repairs performed on this equipment may result in danger to the technician  
or machine operator and will invalidate your factory warranty. For your safety and to avoid  
electrical shock, please observe all safety notes and precautions detailed throughout this  
manual.  
If for any reason you do not understand the test procedures or are unable to perform the  
test/repairs safely, contact the Lincoln Electric Service Department for electrical trou-  
bleshooting assistance before you proceed. Call 1-888-935-3877.  
DESCRIPTION  
This procedure will aid the technician in the removal and replacement of the high voltage  
transformer.  
MATERIALS NEEDED  
3/8” Nut Driver  
7/16” Nut Driver  
Phillips Head Screwdriver (Off-set)  
Wire Cutters  
PRECISION TIG 275  
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F-46  
F-46  
TROUBLESHOOTING & REPAIR  
HIGH VOLTAGE TRANSFORMER  
REMOVAL AND REPLACEMENT (continued)  
Figure F.10 - High Voltage Transformer  
MOUNTING SCREW  
INSULATORS  
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HIGH VOLTAGE  
TRANSFORMER  
REMOVAL PROCEDURE  
9. Using an off set phillips head screw driver,  
remove the four high voltage transformer  
mounting screws. Note insulator position-  
ing. See Figure F.10.  
1. Remove input power to the TIG 275  
machine.  
2. Using the 3/8” nut driver, remove the case  
sides and top.  
10. Remove the high voltage transformer.  
3. Using a 3/8” nut driver, remove the case  
back.  
REPLACEMENT PROCEDURE  
Note: The case back will be connected to  
the fan assembly and will have leads  
connected to it, so just set aside.  
1. Replace the high voltage transformer.  
2. Secure the new transformer using the four  
phillips head mounting screws. Refer to  
Figure F10 for insulator location.  
4. Cut any necessary cable ties.  
5. Disconnect black lead from the high voltage  
transformer connecting to leads 231D and  
231E.  
3. Replace the 3/8” screw securing the spark  
gap assembly box.  
6. Disconnect the black lead from the high  
4. Reconnect leads S and F.  
voltage transformer connecting to the  
capacitor. It may be necessary to cut lead.  
5. Reconnect high voltage transformer lead to  
the capacitor.  
7. Using a 7/16” nut driver disconnect heavy  
black leads S and F. See Figure F.11.  
6. Reconnect leads 231D and 231E to single  
black lead.  
7. Replace any necessary cable ties.  
8. Using a 3/8” nut driver, remove the screw  
securing the spark gap assembly box. See  
Figure F.11. This will allow access to the  
high voltage transformer mounting screws.  
8. Secure the case back using the 3/8” mount-  
ing bolts previously removed.  
9. Replace the case sides and top.  
PRECISION TIG 275  
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F-47  
F-47  
TROUBLESHOOTING & REPAIR  
HIGH VOLTAGE TRANSFORMER  
REMOVAL AND REPLACEMENT (continued)  
Figure F.11 - 3/8” Screw & Leads S and F Locations  
M
O
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E
M
IN  
IM  
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IS  
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SPARK GAP  
ASSEMBLY BOX  
LEADS S & F  
3/8" SCREW  
PRECISION TIG 275  
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F-48  
F-48  
NOTES  
PRECISION TIG 275  
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F-49  
F-49  
TROUBLESHOOTING & REPAIR  
CONTROL BOARD REMOVAL AND REPLACEMENT  
WARNING  
Service and repair should be performed by only Lincoln Electric factory trained personnel.  
Unauthorized repairs performed on this equipment may result in danger to the technician  
or machine operator and will invalidate your factory warranty. For your safety and to avoid  
electrical shock, please observe all safety notes and precautions detailed throughout this  
manual.  
If for any reason you do not understand the test procedures or are unable to perform the  
test/repairs safely, contact the Lincoln Electric Service Department for electrical trou-  
bleshooting assistance before you proceed. Call 1-888-935-3877.  
DESCRIPTION  
This procedure will aid the technician in the removal and replacement of the control board.  
MATERIALS NEEDED  
3/8” Nut Driver  
Phillips Head Screwdriver  
Wire Cutters  
PRECISION TIG 275  
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F-50  
F-50  
TROUBLESHOOTING & REPAIR  
CONTROL BOARD REMOVAL AND REPLACEMENT (continued)  
Figure F.12 - Case Front Screw Location  
CASEFRONT SCREWS  
M
O
D
E
M
IN  
IM  
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IS  
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REMOVAL PROCEDURE  
REPLACEMENT PROCEDURE  
1. Remove input power to the TIG 275  
1. Replace the control board.  
machine.  
2. Mount the new control board in its proper  
position using the eight phillips head mount-  
ing screws.  
3. Replace any necessary cable ties.  
2. Using a 3/8” nut driver, remove the two  
screws from the top of the case front. See  
Figure F.12.  
3. The top front control box cover can now be  
tilted forward to gain access to the control  
board and its plugs.  
4. From left to right, label and disconnect plugs  
J4, J5, J6, J8, J9, J10, J11, J12. See Figure  
F.13.  
4. Reconnect plugs previously removed from  
the control board.  
5. Secure the control box assembly using the  
two 3/8” mounting screws previously  
removed.  
5. Cut any necessary cable ties.  
6. Using a phillips head screwdriver, remove  
the eight P.C. Board mounting screws. See  
Figure F.13.  
7. Carefully maneuver the control board out of  
the front of the machine.  
PRECISION TIG 275  
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F-51  
F-51  
TROUBLESHOOTING & REPAIR  
CONTROL BOARD REMOVAL AND REPLACEMENT (continued)  
Figure F.13 - Control Board Plug Locations  
J4  
J5  
J8  
J6  
J9  
J10  
J11  
J12  
PRECISION TIG 275  
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F-52  
F-52  
NOTES  
PRECISION TIG 275  
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F-53  
F-53  
TROUBLESHOOTING & REPAIR  
SCR BRIDGE ASSEMBLY REMOVAL AND REPLACEMENT  
WARNING  
Service and repair should be performed by only Lincoln Electric factory trained personnel.  
Unauthorized repairs performed on this equipment may result in danger to the technician  
or machine operator and will invalidate your factory warranty. For your safety and to avoid  
electrical shock, please observe all safety notes and precautions detailed throughout this  
manual.  
If for any reason you do not understand the test procedures or are unable to perform the  
test/repairs safely, contact the Lincoln Electric Service Department for electrical trou-  
bleshooting assistance before you proceed. Call 1-888-935-3877.  
DESCRIPTION  
This procedure will aid the technician in the removal and replacement of the SCR bridge  
for maintenance or replacement.  
MATERIALS NEEDED  
3/8” Nut Driver  
1/2” Nut Driver  
7/16” Nut Driver  
Pliers  
Crimp Wire Cutters  
PRECISION TIG 275  
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F-54  
F-54  
TROUBLESHOOTING & REPAIR  
SCR BRIDGE ASSEMBLY REMOVAL AND REPLACEMENT (continued)  
REMOVAL PROCEDURE  
REPLACEMENT PROCEDURE  
1. Remove input power to the TIG 275  
1. Replace the SCR bridge.  
machine.  
2. Replace the four SCR bridge mounting  
2. Using the 3/8” nut driver, remove the case  
sides and top.  
bolts previously removed.  
Note: Be sure to replace insulating wash-  
3. Label and cut leads G1 and G2. See  
ers in their proper positions.  
Figure F.14.  
3. Reconnect lead 218 and Pos. lead previ-  
4. Label and cut leads G3 and G4. See  
ously removed.  
Figure F.14.  
4. Replace the shunt and lead 220A previous-  
ly removed.  
5. Replace the 1/2” bolt securing lead 216 and  
the aluminum lead X1 originating from the  
main transformer.  
5. Remove the 1/2 “ nut securing leads B and  
217. See Figure F.14.  
6. Using a 7/16” nut driver, disconnect Pos.  
lead and lead 218.See Figure F.14.  
7. Using a 1/2” nut driver, disconnect Pos.  
6. Reconnect the negative lead to the free  
lead and lead 218. See Figure F.14.  
wheeling diode.  
8. Using a 1/2” nut driver, remove lead 216  
and aluminum lead X1 connecting to the  
main transformer. See Figure F.14. Note  
washer placement upon removal.  
9. Using a 1/2” nut driver, disconnect lead  
220A and shunt from the output bridge. See  
Figure F.14.  
7. Replace the 1/2” bolt securing leads B and  
217 previously removed.  
8. Reconnect leads G1, G2, G3, and G4.  
Splice, solder and insulate as necessary.  
9. Replace case sides and top.  
10. Using a 3/8” nut driver, remove the four  
SCR bridge mounting bolts. Note insulator  
washer placement upon removal.  
PRECISION TIG 275  
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F-55  
F-55  
TROUBLESHOOTING & REPAIR  
SCR BRIDGE REMOVAL AND REPLACEMENT (continued)  
Figure F.14 - SCR BRIDGE CONNECTIONS  
LIFT BAIL STABILIZER  
217  
X1  
B
G2  
Negative  
216  
G3  
G4  
Shunt  
G1  
Pos.  
218  
220A  
Bridge  
Mounting  
Bolts  
PRECISION TIG 275  
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F-56  
F-56  
TROUBLESHOOTING & REPAIR  
MOUNTING OF STUD TYPE DIODES TO ALUMINUM HEAT SINKS (CONT’D)  
PROCEDURE  
DIODE STUD  
SIZE  
FOOT-  
INCH-  
POUNDS  
POUNDS  
1. Loosen the appropriate diode nut and remove the  
diode that is to be replaced.  
3/4 - 16  
3/8 - 24  
1/4 - 28  
25-27  
10 .5  
300-324  
125+0/-5  
22-25  
2. Clean the area on the heat sink around the diode  
mounting surface using a putty knife, or similar  
tool, DO NOT SCRATCH THE DIODE MOUNTING  
SURFACE.  
3. Polish each heat sink's mounting surface using  
NO. 000 fine steel wool. Wipe surface clean with  
a lint free cloth or paper towel.  
4. Inspect the mounting surfaces of each new diode.  
Remove all burrs and wipe clean. Do not use steel  
wool or any abrasive cleanser on the diode  
mounting surface.  
5. Apply a thin (0.0003" to 0.0007") uniform layer of  
E1868 (Dow Corning 340) heat sink compound to  
the heat sink mounting surface.  
a. Do not apply compound to diode stud or  
mounting threads.  
b. The diode threads must be clean and free of  
defects so that the nut can be finger tightened  
before applying torque. A "slip" type torque  
wrench must be used to tighten the diode nut.  
6. Tighten the diode nuts to the specifications in the  
following table.  
a. The nuts for diodes with steel studs are to be  
started by hand and then torqued as per the  
following table.  
b. The nuts for diodes with copper studs are to  
run on all the way by hand then torqued as per  
the following table.  
c. Turn a minimum of 1/2 turn more while  
torquing per the table.  
PRECISION TIG 375  
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F-57  
F-57  
TROUBLESHOOTING & REPAIR  
POLARITY SWITCH REMOVAL AND REPLACEMENT  
WARNING  
Service and repair should be performed by only Lincoln Electric factory trained personnel.  
Unauthorized repairs performed on this equipment may result in danger to the technician  
or machine operator and will invalidate your factory warranty. For your safety and to avoid  
electrical shock, please observe all safety notes and precautions detailed throughout this  
manual.  
If for any reason you do not understand the test procedures or are unable to perform the  
test/repairs safely, contact the Lincoln Electric Service Department for electrical trou-  
bleshooting assistance before you proceed. Call 1-888-935-3877.  
DESCRIPTION  
This procedure will aid the technician in the removal and replacement of the polarity  
switch.  
MATERIALS NEEDED  
3/8” Nut Driver  
1/2” Wrench  
7/16” Wrench  
Phillips Head Screw Driver  
Slot Head Screw Driver (2 Required)  
PRECISION TIG 275  
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F-58  
F-58  
TROUBLESHOOTING & REPAIR  
POLARITY SWITCH REMOVAL AND REPLACEMENT (continued)  
Figure F.15 - Switch Location  
M
O
D
E
M
I
N
I
M
U
M
D
I
S
P
L
A
Y
L
O
C
A
L
A
C
B
A
R
L
A
E
N
M
C
O
T
E
E
!
W
A
R
N
I
N
G
M
A
X
I
M
U
M
O
N
P
O
W
E
R
D
O
F
A
C
C
F
P
O
~
S
T
F
L
O
W
S
e
Q
U
A
R
E
f
W
a
t
A
V
L
u
r
i
E
n
I
g
N
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.
.
.
W
E
C
L
MPO  
R
O
E
I
S
O
O
C
L
U
R
R
N
T
C
D
SE  
C
C
+
T
R
A
I
C
T
R
E
C
H
T
T
M
N
O
L
O
P
G
Y
D
O
R
N
IL  
W
O
T
H
S
W
E
IT  
D
E
W
E
C
IN  
H
G
L
C
I
S
I
O
N
T
I
T
M
G
T
H
E
L
IN  
C
3
O
L
N
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L
7
5
N
Y
C
E
C
T
R
IC  
C
O
M
P
A
L
E
V
E
L
A
N
D
,
O
H
IO  
U
S
A
9. Using a 7/16” nut driver remove the two  
polarity switch mounting nuts located behind  
the previously removed nameplate.  
10. The polarity switch is ready for removal.  
REMOVAL PROCEDURE  
1. Remove the input to the PRECISION TIG  
275 machine.  
2. Using the 3/8” nut driver, remove the case  
sides and top.  
REPLACEMENT PROCEDURE  
3. Locate the polarity switch. See Figure F.15.  
4. Using a 1/2”wrench label and disconnect  
leads B,C,252, Pos, Neg, D2 diode assem-  
bly,S,253, choke lead, X2 and all leads from  
the main transformer. Be sure to label leads  
for reassembly.  
1. Replace the polarity switch.  
2. Secure the polarity switch in its original posi-  
tion with the 7/16” mounting nuts.  
3. Firmly press the lower nameplate back into  
its original position on the case front.  
5. Disconnect leads 265 and 266A using quick  
disconnects.  
4. Press the polarity switch handle back onto  
its shaft.  
6. Using a phillips head screw driver, remove  
the screw from the polarity switch handle.  
See Figure F.15.  
5. Secure polarity switch handle with the  
phillips head screw previously removed.  
7. With the 2 slot head screw drivers, carefully  
6. Reconnect leads 265 and 266A previously  
pry the polarity switch handle  
removed.  
8. Carefully peel back the lower nameplate on  
the case front located around the polarity  
switch to gain access to the polarity switch  
mounting nuts.  
7. Reconnect all previously removed leads to  
their proper terminals. See Wiring Diagram.  
8. Replace case sides and top.  
NOTE: Do not remove the sticker completely.  
PRECISION TIG 275  
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F-59  
F-59  
TROUBLESHOOTING & REPAIR  
SCR REMOVAL AND REPLACEMENT  
WARNING  
Service and repair should be performed by only Lincoln Electric factory trained personnel.  
Unauthorized repairs performed on this equipment may result in danger to the technician  
or machine operator and will invalidate your factory warranty. For your safety and to avoid  
electrical shock, please observe all safety notes and precautions detailed throughout this  
manual.  
If for any reason you do not understand the test procedures or are unable to perform the  
test/repairs safely, contact the Lincoln Electric Service Department for electrical trou-  
bleshooting assistance before you proceed. Call 1-888-935-3877.  
DESCRIPTION  
The following procedure will aid the technician in removing the SCRs from the output rec-  
tifier heat sink for maintenance or replacement.  
MATERIALS NEEDED  
No. 000 Fine Steel Wool  
Penetrox A-13 (Lincoln E2529) or Penetrox A  
7/16” Open End Wrench  
Allen Head Type Wrenches  
PRECISION TIG 275  
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F-60  
F-60  
TROUBLESHOOTING & REPAIR  
SCR REMOVAL AND REPLACEMENT (continued)  
Figure F.16 - SCR DETAILS  
Gate  
Anode  
Cathode  
Outer Metal  
Ring  
5. Clean the area on the heat sink around the  
SPECIAL INSTRUCTIONS  
SCR mounting surface, using a putty knife  
or similar tool. DO NOT SCRATCH THE  
SCR MOUNTING SURFACE.  
NOTE: Before disassembling the existing recti-  
fier, note toward which heat sink the outer  
metal ring of the power SCR is mounted. Also,  
note the positioning of the gate lead of the  
SCR. Failure to reinstall the new SCR in the  
same orientation as the original may result in  
subsequent damage to the new SCR and  
other components of the welder. See Figure  
F.16.  
6. Polish each heat sinkʼs mounting surface  
using NO.000 fine steal wool. Wipe surface  
clean with a lint free cloth or paper towel.  
7. Inspect the mounting surfaces of each new  
SCR.  
a. Remove all burrs and wipe clean. Do  
not use steel wool or any abrasive  
cleanser on the SCR mounting sur-  
faces.  
CAUTION  
The unclamping and clamping procedure out-  
lined below is critical for the prevention of  
internal SCR damage. Failure to follow this  
procedure may result in subsequent damage  
of the SCR. Handle all SCRs with care.  
8. Apply a thin (0.001” to 0.003”) layer of  
PENETROX A-13 (Lincoln Electric #E2529)  
or PENTROX A, heat sink compound, to  
each heat sinkʼs SCR mounting surface.  
a. Care must be used to prevent foreign  
material contamination of the SCR to  
heat sink junction.  
PROCEDURE  
1. Remove the main input supply power to the  
machine.  
9. Place the new SCR between the heat  
sinks. Be sure that the outer metal ring of  
the SCR is facing toward the same heat  
sink as the old SCRʼs metal ring. Be sure  
that the roll pin of the heat sink engages  
the “hole” in the SCR. The SCR contact  
surfaces must sit flat against both heat sink  
surfaces.  
2. Perform the SCR/Diode Rectifier  
Assembly Removal procedure.  
3. Using a 7/16” open end wrench, alternately  
loosen nuts 1/2 turn each until heat sinks  
are loose. Remove nuts and leaf spring. IT  
IS RECOMMENDED THAT NEW HARD-  
WARE, LEAF SPRING AND HOUSING BE  
USED FOR ASSEMBLY.  
10. Perform the SCR/Diode Rectifier  
Assembly Replacement Procedure.  
4. Remove the old SCR.  
11. Replace the case sides and top.  
PRECISION TIG 275  
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F-61  
F-61  
TROUBLESHOOTING & REPAIR  
RETEST AFTER REPAIR  
Should a machine under test be rejected for any reason requiring the removal of any  
mechanical part that could effect the machineʼs electrical characteristics, or if any electrical  
components are required or replaced, the machine must be retested.  
INPUT IDLE AMPS  
Input Volts/Hertz  
Maximum Idle Amps  
(without PFC)  
Maximum Idle Amps  
(without PFC)  
208/60  
230/60  
460/60  
575/60  
6
5
3
2
36  
32  
16  
13  
OPEN CIRCUIT VOLTAGES  
MAXIMUM AC OPEN CIRCUIT VOLTAGE  
MAXIMUM DC OPEN CIRCUIT VOLTAGE  
75 VAC  
68 VDC  
MAXIMUM ACCEPTABLE OUTPUT VOLTAGE  
AT MINIMUM OUTPUT SETTINGS  
DC TIG Mode  
2 Amps @ 20 Volts  
MAXIMUM ACCEPTABLE OUTPUT VOLTAGE  
AT MAXIMUM OUTPUT SETTINGS  
DC TIG Mode  
300 Amps @ 32 Volts  
RECOMMENDED METERS FOR MACHINE OUTPUT TESTS  
VOLTMETER: AC and DC True RMS Meter - Fluke 8922A or equivalent  
AMMETER: Columbia Type AX AC or DC Tong Ammeter  
IMPORTANT: IF OTHER TYPE METERS ARE USED, RESULTS MAY NOT BE ACCURATE.  
PRECISION TIG 275  
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F-62  
F-62  
NOTES  
PRECISION TIG 275  
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G-1  
G-1  
ELECTRICAL DIAGRAMS  
TABLE OF CONTENTS  
ELECTRICAL DIAGRAMS SECTION  
Electrical Diagrams Section ..........................................................................................Section G  
Wiring Diagram (Entire Machine) Code 10806 (G4031) .............................................................G-2  
Wiring Diagram (Entire Machine) Code 10807 (G4031-1) ..........................................................G-3  
Wiring Diagram (Entire Machine) Code 10893 (G4031-2) ..........................................................G-4  
Wiring Diagram (Entire Machine) Code 11158 (G5692)..............................................................G-5  
Wiring Diagram (Entire Machine) Code 11159 (G5692-1)...........................................................G-6  
Schematic (Entire Machine) Codes below 11000 (G4075) .........................................................G-7  
Schematic (Entire Machine) Codes above 11000 (G5691).........................................................G-8  
Control P.C. Board Schematic Codes below 11000 (G3908 Page 1) ........................................G-9  
Control P.C. Board Schematic Codes below 11000 (G3908 Page 2) .......................................G-10  
Control P.C. Board Schematic Codes below 11000 (G3908 Page 3)........................................G-11  
Control P.C. Board Assembly Codes below 11000(G3909-2) ...................................................G-12  
Control P.C. Board Schematic Codes above 11000 (G4762 Page 1)......................................G-13  
Control P.C. Board Schematic Codes above 11000 (G4762 Page 2)......................................G-14  
Control P.C. Board Schematic Codes above 11000 (G4762 Page 3)......................................G-15  
Control P.C. Board Schematic Codes above 11000 (G4762 Page 4)......................................G-16  
Control P.C. Board Schematic Codes above 11000 (G4762 Page 5)......................................G-17  
Control P.C. Board Assembly Codes above 11000 (G4763-1)..................................................G-18  
Protection P.C. Board Schematic (M16115) ..............................................................................G-19  
Protection P.C. Board Assembly (M16062-1) ............................................................................G-20  
ByPass / Stabilizer P.C. Board Schematic (S22530-1) (Code 10806 & 10807)........................G-21  
ByPass / Stabilizer P.C. Board Assembly (L10121-1) (Code 10806 & 10807) .........................G-22  
ByPass and CE P.C. Board Schematic (S24206) (Code 10893) ..............................................G-23  
ByPass and CE P.C. Board Assembly (L10882-1) (Code 10893).............................................G-24  
TIG Option P.C. Board Schematic Codes below 11000 (G4039 Page 1) .................................G-25  
TIG Option P.C. Board Schematic Codes below 11000 (G4039 Page 2) .................................G-26  
TIG Option P.C. Board Assembly Codes below 11000 (G4040-2) ............................................G-27  
TIG Option P.C. Board Schematic Codes above 11000 (G4760 Page 1).................................G-28  
TIG Option P.C. Board Schematic Codes above 11000 (G4760 Page 2).................................G-29  
TIG Option P.C. Board Schematic Codes above 11000 (G4760 Page 3).................................G-30  
TIG Option P.C. Board Assembly Codes above 11000 (G4761-1)............................................G-31  
PRECISION TIG 275  
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G-2  
G-2  
ELECTRICAL DIAGRAMS  
WIRING DIAGRAM - ENTIRE MACHINE - CODE 10806 (G4031)  
CONTROL PANEL (VIEWED FROM REAR)  
L1 (U)  
L2 (V)  
H1  
460 VOLT CONNECTION  
CONNECT STRAP TO  
HIGH (H4) (AS SHOWN)  
PRECISION TIG 275 WIRING DIAGRAM  
1
2
3
4
5
1
2
3
4
5
6
306  
303  
301  
S1  
230 VOLT CONNECTION  
CONNECT STRAP TO  
MID (H3)  
304B  
302  
POWER SWITCH  
METER  
H4  
H3  
H2  
6
A
L1 (U)  
208 VOLT CONNECTION  
CONNECT STRAP TO  
LOW (H2)  
(VIEWED FROM REAR)  
C1  
C2  
MID  
C5  
C4  
HIGH  
LOW  
250  
251  
H1  
L5  
CONTROL PC BOARD  
N.E.  
MINIMUM  
OUTPUT  
L2 (V)  
GROUND  
COM  
DISPLAY  
POWER FACTOR  
CAPACITORS  
(OPTIONAL)  
301  
302  
303  
304  
304A  
306  
1
2
3
4
5
6
RECONNECT PANEL  
R4  
267  
J8  
X5  
63.5VAC  
X6  
S
F
H2 (208V)  
H3 (230V)  
268  
TO GROUND PER  
NATIONAL  
ELECTRICAL CODE  
1
2
W 221  
R 222  
J6  
X3  
231  
H4 (460V)  
X9  
201  
S
231A  
115VAC  
311  
312  
313  
314  
315  
316  
317  
318  
319  
320  
321  
322  
L4  
1
S
F
L6  
216  
2
3
F
232  
18VAC  
X10  
X1  
X4  
313B  
204  
4
MAXIMUM  
OUTPUT  
5
X1  
LOCAL  
STICK  
BALANCE  
POST FLOW  
SCR1  
SCR2  
S
L12  
6
J9  
( + )  
7
G1  
X7  
S
F
78VAC  
8
9
10  
11  
12  
W209  
R210  
1
G1  
G3  
20VAC  
R2  
R1  
R3  
218  
G2  
POS  
2
3
X8  
F
X2  
4
G4  
G2  
217  
220  
313A  
TIG  
MODE  
REMOTE  
5
T1  
J4  
6
POLARITY SWITCH MICRO SWITCH  
L1  
7
AC A-C, D-E, B-F  
DC+ B-D, C-E, A-F, G-H  
DC- B-D, A-E, C-F, G-H  
OPEN  
CLOSED  
CLOSED  
8
9
218  
216  
217  
G3  
232  
FRONT GANG  
D
10  
115VAC  
MICRO-SWITCH  
REAR GANG  
C8  
CB1  
15A  
C9  
D2  
B
S2A  
NO  
H
W
B
1
6
E
F
NC  
233  
A
SCR3  
331  
332  
333  
334  
335  
(STICK)  
(AUTO BAL)  
(REMOTE)  
(THERMAL)  
+
(P. FLOW)  
233B  
8
231  
G
-
W
B
2
4
2
-
-
W
-
W
-
W
+
B
+
+
B
+
220  
C
R
G
G
G
7
( - )  
Y
W
B
B
B
W
3
N.F.  
B
W
J10  
1
0
8
POS  
D1  
CR4  
B
W
B
4
X2  
SCR4  
CR4  
6
9
G4  
W
B
252  
253  
5
1
9
263  
234  
10  
S2  
SV2  
WATER VALVE  
(OPTIONAL)  
L7  
2
269  
270  
271  
220B  
POLARITY  
SWITCH  
(REAR VIEW, SHOWN  
IN AC POSITION)  
10  
1
3
2
5
4
6
3
11  
N.D.  
N.C.  
J7  
265  
266  
262  
263  
213  
214  
6
12  
5
13  
4
14  
7
C1,C2  
C4,C5  
C6  
POWER FACTOR CAPACITORS, 50/460 (OPTIONAL)  
BY-PASS CAPACITORS, .0047  
HIGH VOLTAGE CAPACITOR, .0015/12kV  
PHASE SHIFT CAPACITOR, 15uF/250VAC  
HIGH FREQ PROTECTION CAPACITORS, .22/400  
CIRCUIT BREAKER, 15 AMP  
ADVANCED CONTROL PANEL  
(OPTIONAL)  
J3  
J11  
BACKGROUND  
RECTIFIER  
271A  
R7  
C7  
1
1
2
2
3
3
4
4
5
6
7
7
8
8
9 10  
N.C.  
DOWN SLOPE  
BACKGROUND  
ON TIME  
FREQ  
C8,C9  
CB1  
CR4  
D1  
269  
267  
268  
R8  
271  
270  
12V DC RELAY COIL  
OR  
J3  
R11  
R12  
R10  
R9  
201  
204  
262  
263  
FREE WHEELING DIODE  
BACKGROUND DIODE  
OUTPUT INDUCTOR (CHOKE)  
HIGH FREQ INDUCTORS  
RF TOROID CHOKES  
OUTPUT CONTROL POTENTIOMETER, 10K  
BALANCE CONTROL POTENTIOMETER, 10K  
POST FLOW POTENTIOMETER, 10K  
MIN OUTPUT POTENTIOMETER, 10K  
PHASE SHIFT RESISTOR, 200/100  
HOLDING RESISTOR, 50/225  
L13  
15  
D2  
L1  
401C  
W209  
R210  
8
16  
201  
204  
W209  
R210  
5
6
9 10  
L2,L3  
L4 -L13  
R1  
220B  
220A  
R2  
R3  
R4  
R5  
R6  
R7  
R8  
R9  
R10  
R11  
R12  
S1  
401  
402  
403  
404  
405  
406  
407  
408  
409  
410  
411  
W
1
2
L10  
3
(PULSE ON)  
4-STEP  
ON  
4
5
-
+
RESISTOR, 20/100  
RESISTOR, 5/50  
B
G
6
214  
7
W
S
FREQ CONTROL POTENTIOMETER, 10K  
ON TIME CONTROL POTENTIOMETER, 10K  
BACKGROUND POTENTIOMETER, 10K  
DOWN SLOPE POTENTIOMETER, 10K  
INPUT POWER SWITCH  
FAN  
8
9
10  
11  
12  
213  
OFF  
2-STEP  
C
TRANSFORMER  
PRIMARY  
THERMOSTAT  
TRIGGER  
PULSE  
TRANSFORMER  
SECONDARY  
THERMOSTAT  
BYPASS/  
S2  
POLARITY SWITCH  
J1  
STABILIZER  
PC BOARD  
260  
S2A  
MICROSWITCH ON POLARITY SWITCH  
SCR1,2,3,4 MAIN POWER SCR'S  
233A  
SV1  
SV2  
T1  
GAS SOLENOID VALVE, 115VAC  
WATER SOLENOID VALVE, 115VAC (OPTIONAL)  
MAIN TRANSFORMER  
HIGH VOLTAGE TRANSFORMER  
HIGH FREQ TRANSFORMER  
1
2
3
4
5
6
7
8
9 10  
1
2
3
4
5
7
GAS VALVE  
235  
J2  
SV1  
233A  
231A  
T2  
T3  
231D  
J5A  
231E  
E
F
COMPONENT VALUE  
6
8
LEAD COLORING CODE:  
UNITS:  
L11  
B-BLACK  
G-GREEN  
O-ORANGE  
R-RED  
U-BLUE  
W-WHITE  
Y-YELLOW  
RESISTORS:  
N.B.  
L9  
OHMS/WATTS  
CAPACITORS:  
MFD/VOLTS  
PROTECTION PCB  
N.A. CONNECTION IS PIN TO PIN BETWEEN J23 AND J5.  
N.B. ROBOTIC INTERFACE CONNECTION.  
N.C. REMOVE JUMPER PLUG IN J3 WHEN INSTALLING  
TIG OPTION PC BOARD.  
N.D. DISCONNECT JUMPER LEAD BETWEEN PIN 1 AND  
PIN 2 IN J3 TO DOUBLE PREFLOW & POSTFLOW TIMES.  
N.E. DISPLAY TOGGLE SHOWN IN MIN AMP POSITION.  
N.F. PLUGS INTO LOWER SWITCHED RECEPTACLE.  
L2  
C6  
S
1
A
B
C
D
E
F
A
B
C
D
E
F
115VAC  
2
3
5
6
4
260  
235  
T3  
R6  
SPARK  
GAP  
1
2
3
4
5
7
6
8
CONNECTOR PIN NUMBERS:  
1
2
3
4
5
7
T2  
J12  
A
B
C
D
E
F
4
1
2
3
6
5
EXAMPLE: THIS IS PIN 7  
0F CONNECTOR J5  
L8  
1 2 3  
7
236  
233A  
284  
285  
J23  
J22  
J5  
10K A-B  
AT MINIMUM  
L3  
N.A.  
F
14  
LATCH  
8
1 2 3  
8
237  
J5  
6
8
OPTIONAL  
REMOTE  
FRONT  
ELECTRODE  
WORK  
REMOTE  
RECEPTACLE  
VIEW OF CONNECTOR ON PC BOARD  
ELECTRICAL SYMBOLS PER E1537.  
R5  
TM  
C7  
AMPTROL  
ARC STARTER AS'BLY  
REAR  
ELECTRODE  
236B  
B
G4031  
NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual. The wiring diagram specific to your code is pasted inside one of the enclosure panels of your machine.  
®
PRECISION TIG 275  
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G-3  
G-3  
ELECTRICAL DIAGRAMS  
WIRING DIAGRAM - ENTIRE MACHINE - CODE 10807 (G4031-1)  
CONTROL PANEL (VIEWED FROM REAR)  
L1 (U)  
L2 (V)  
H1  
PRECISION TIG 275 WIRING DIAGRAM  
575 VOLT CONNECTION  
CONNECT STRAP TO  
HIGH (H4) (AS SHOWN)  
1
2
3
4
5
1
2
3
4
5
6
306  
303  
301  
S1  
460 VOLT CONNECTION  
CONNECT STRAP TO  
LOW (H2)  
304B  
302  
POWER SWITCH  
METER  
H4  
H2  
6
A
L1 (U)  
(VIEWED FROM REAR)  
C1  
C2  
MID  
250  
C5  
C4  
HIGH  
LOW  
251  
H1  
L5  
CONTROL PC BOARD  
N.E.  
MINIMUM  
OUTPUT  
L2 (V)  
GROUND  
COM  
RECONNECT PANEL  
DISPLAY  
POWER FACTOR  
CAPACITORS  
(OPTIONAL)  
301  
302  
303  
304  
304A  
306  
1
2
3
4
5
6
R4  
267  
J8  
X5  
63.5VAC  
X6  
S
F
H2 (460V)  
268  
TO GROUND PER  
NATIONAL  
ELECTRICAL CODE  
1
2
W 221  
R 222  
J6  
X3  
231  
H4 (575V)  
X9  
201  
S
F
231A  
115VAC  
X4  
311  
312  
313  
314  
315  
316  
317  
318  
319  
320  
321  
322  
L4  
1
S
F
L6  
216  
2
3
232  
18VAC  
X10  
X1  
313B  
204  
4
MAXIMUM  
OUTPUT  
5
X1  
LOCAL  
STICK  
BALANCE  
POST FLOW  
SCR1  
SCR2  
S
L12  
6
J9  
+ ( )  
7
G1  
X7  
S
F
78VAC  
8
9
10  
11  
12  
W209  
R210  
1
G1  
G3  
20VAC  
R2  
R1  
R3  
218  
G2  
POS  
2
3
X8  
F
X2  
4
G4  
G2  
217  
220  
313A  
TIG  
MODE  
REMOTE  
5
T1  
J4  
6
POLARITY SWITCH MICRO SWITCH  
L1  
7
AC A-C, D-E, B-F  
DC+ B-D, C-E, A-F, G-H  
DC- B-D, A-E, C-F, G-H  
OPEN  
CLOSED  
CLOSED  
8
9
218  
216  
217  
G3  
232  
FRONT GANG  
D
10  
115VAC  
MICRO-SWITCH  
REAR GANG  
C8  
CB1  
15A  
C9  
D2  
B
S2A  
NO  
H
W
B
1
6
E
F
NC  
233  
A
SCR3  
331  
332  
333  
334  
335  
(STICK)  
(AUTO BAL)  
(REMOTE)  
(THERMAL)  
+
(P. FLOW)  
233B  
8
231  
G
-
W
B
2
4
2
-
-
W
-
W
-
W
+
B
+
+
B
+
220  
C
R
G
G
G
7
( - )  
Y
W
B
B
B
W
3
N.F.  
B
W
J10  
1
0
8
POS  
D1  
CR4  
B
W
B
4
X2  
SCR4  
CR4  
6
9
G4  
W
B
252  
253  
5
1
9
263  
234  
10  
S2  
SV2  
WATER VALVE  
(OPTIONAL)  
L7  
2
269  
270  
271  
220B  
POLARITY  
SWITCH  
(REAR VIEW, SHOWN  
IN AC POSITION)  
10  
1
3
2
5
4
6
3
11  
N.D.  
N.C.  
J7  
265  
266  
262  
263  
213  
214  
6
12  
5
13  
4
14  
7
C1,C2  
C4,C5  
C6  
POWER FACTOR CAPACITORS, 50/460 (OPTIONAL)  
BY-PASS CAPACITORS, .0047  
HIGH VOLTAGE CAPACITOR, .0015/12kV  
PHASE SHIFT CAPACITOR, 15uF/250VAC  
HIGH FREQ PROTECTION CAPACITORS, .22/400  
CIRCUIT BREAKER, 15 AMP  
ADVANCED CONTROL PANEL  
(OPTIONAL)  
J3  
J11  
BACKGROUND  
RECTIFIER  
271A  
R7  
C7  
1
1
2
2
3
3
4
4
5
6
7
7
8
8
9 10  
N.C.  
DOWN SLOPE  
BACKGROUND  
ON TIME  
FREQ  
C8,C9  
CB1  
CR4  
D1  
269  
267  
268  
R8  
271  
270  
12V DC RELAY COIL  
OR  
J3  
R11  
R12  
R10  
R9  
201  
204  
262  
263  
FREE WHEELING DIODE  
BACKGROUND DIODE  
OUTPUT INDUCTOR (CHOKE)  
HIGH FREQ INDUCTORS  
RF TOROID CHOKES  
OUTPUT CONTROL POTENTIOMETER, 10K  
BALANCE CONTROL POTENTIOMETER, 10K  
POST FLOW POTENTIOMETER, 10K  
MIN OUTPUT POTENTIOMETER, 10K  
PHASE SHIFT RESISTOR, 200/100  
HOLDING RESISTOR, 50/225  
L13  
15  
D2  
L1  
401C  
W209  
R210  
8
16  
201  
204  
W209  
R210  
5
6
9 10  
L2,L3  
L4 -L13  
R1  
220B  
220A  
R2  
R3  
R4  
R5  
R6  
R7  
R8  
R9  
R10  
R11  
R12  
S1  
401  
402  
403  
404  
405  
406  
407  
408  
409  
410  
411  
W
1
2
L10  
3
(PULSE ON)  
4-STEP  
ON  
4
5
-
+
RESISTOR, 20/100  
RESISTOR, 5/50  
B
G
6
214  
7
8
9
W
S
FREQ CONTROL POTENTIOMETER, 10K  
ON TIME CONTROL POTENTIOMETER, 10K  
BACKGROUND POTENTIOMETER, 10K  
DOWN SLOPE POTENTIOMETER, 10K  
INPUT POWER SWITCH  
FAN  
213  
10  
11  
12  
OFF  
2-STEP  
C
TRANSFORMER  
PRIMARY  
THERMOSTAT  
TRIGGER  
PULSE  
TRANSFORMER  
SECONDARY  
THERMOSTAT  
BYPASS/  
S2  
POLARITY SWITCH  
J1  
STABILIZER  
PC BOARD  
260  
S2A  
MICROSWITCH ON POLARITY SWITCH  
SCR1,2,3,4 MAIN POWER SCR'S  
233A  
SV1  
SV2  
T1  
GAS SOLENOID VALVE, 115VAC  
WATER SOLENOID VALVE, 115VAC (OPTIONAL)  
MAIN TRANSFORMER  
HIGH VOLTAGE TRANSFORMER  
HIGH FREQ TRANSFORMER  
1
2
3
4
5
6
7
8
9 10  
1
2
3
4
5
7
GAS VALVE  
235  
J2  
SV1  
233A  
231A  
T2  
T3  
231D  
J5A  
231E  
E
F
COMPONENT VALUE  
6
8
LEAD COLORING CODE:  
UNITS:  
L11  
B-BLACK  
G-GREEN  
O-ORANGE  
R-RED  
U-BLUE  
W-WHITE  
Y-YELLOW  
RESISTORS:  
N.B.  
L9  
OHMS/WATTS  
CAPACITORS:  
MFD/VOLTS  
PROTECTION PCB  
N.A. CONNECTION IS PIN TO PIN BETWEEN J23 AND J5.  
N.B. ROBOTIC INTERFACE CONNECTION.  
N.C. REMOVE JUMPER PLUG IN J3 WHEN INSTALLING  
TIG OPTION PC BOARD.  
N.D. DISCONNECT JUMPER LEAD BETWEEN PIN 1 AND  
PIN 2 IN J3 TO DOUBLE PREFLOW & POSTFLOW TIMES.  
N.E. DISPLAY TOGGLE SHOWN IN MIN AMP POSITION.  
N.F. PLUGS INTO LOWER SWITCHED RECEPTACLE.  
L2  
C6  
S
1
A
B
C
D
E
F
A
B
C
D
E
F
115VAC  
2
3
5
6
4
260  
235  
T3  
R6  
SPARK  
GAP  
1
2
3
4
5
7
6
8
CONNECTOR PIN NUMBERS:  
1
2
3
4
5
7
T2  
J12  
A
B
C
D
E
F
4
1
2
3
6
5
EXAMPLE: THIS IS PIN 7  
0F CONNECTOR J5  
L8  
1 2 3  
7
236  
233A  
284  
285  
J23  
J22  
J5  
10K A-B  
AT MINIMUM  
L3  
N.A.  
F
14  
LATCH  
8
1 2 3  
8
237  
J5  
6
8
OPTIONAL  
REMOTE  
FRONT  
WORK  
REMOTE  
RECEPTACLE  
VIEW OF CONNECTOR ON PC BOARD  
ELECTRICAL SYMBOLS PER E1537.  
ELECTRODE  
R5  
TM  
C7  
AMPTROL  
ARC STARTER AS'BLY  
REAR  
ELECTRODE  
236B  
B
G4031-1  
NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual. The wiring diagram specific to your code is pasted inside one of the enclosure panels of your machine.  
®
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
G-4  
G-4  
ELECTRICAL DIAGRAMS  
WIRING DIAGRAM - ENTIRE MACHINE - CODE 10893 (G4031-2)  
415 VOLT CONNECTION  
CONNECT STRAP TO  
HIGH (H4) (AS SHOWN)  
CONTROL PANEL (VIEWED FROM REAR)  
380-400 VOLT CONNECTION  
CONNECT STRAP TO  
MID (H3)  
L1 (U)  
L2 (V)  
H1  
PRECISION TIG 275 WIRING DIAGRAM  
220-230 VOLT CONNECTION  
CONNECT STRAP TO  
LOW (H2)  
1
2
3
4
5
1
2
3
4
5
6
306  
303  
301  
S1  
304B  
302  
POWER SWITCH  
METER  
PROTECTIVE BONDING CIRCUIT  
220VAC  
220 VAC  
RECEPT.  
H4  
H3  
H2  
6
51  
A
RECONNECT PANEL SUPPORT  
L1 (U)  
CB2  
5A  
(VIEWED FROM REAR)  
C1  
C2  
50  
GND5  
GND6  
GND1  
GND-H  
GND-H2  
GND4  
52  
MID  
L1A  
L2A  
250  
BYPASS  
PC BOARD  
HIGH  
LOW  
251  
H1  
50A  
L5  
CONTROL PC BOARD  
115 VAC  
RECEPT.  
GAS  
VALVE  
CASE  
BACK  
T1  
TRANS.  
FOOT  
TO GROUND PER  
NATIONAL  
ELECTRIC CODE  
CONTROL  
PANEL  
CASE  
FRONT  
N.E.  
MINIMUM  
OUTPUT  
L2 (V)  
COM  
DISPLAY  
POWER FACTOR  
CAPACITORS  
(OPTIONAL)  
301  
302  
303  
304  
304A  
306  
1
2
3
4
5
6
GROUND  
RECONNECT PANEL  
267  
X5  
63.5VAC  
X6  
S
F
R4  
J8  
H2 (220V)  
H3 (380V)  
H4 (415V)  
268  
X3  
231  
231A  
S
TO GROUND PER  
NATIONAL  
1
2
W 221  
R 222  
J6  
250  
H5 (440V)  
X9  
115VAC  
ELECTRICAL CODE  
311  
312  
313  
314  
315  
316  
317  
318  
319  
320  
321  
322  
L4  
1
S
F
201  
204  
L6  
216  
X4  
105VAC  
X14  
232  
52  
2
3
18VAC  
X10  
X1  
313B  
4
F
MAXIMUM  
OUTPUT  
5
LOCAL  
STICK  
BALANCE  
POST FLOW  
SCR1  
L12  
6
X1  
J9  
S
( + )  
7
G1  
X7  
S
F
8
9
10  
11  
12  
W209  
R210  
78VAC  
1
G1  
G3  
20VAC  
R2  
R1  
R3  
218  
G2  
POS  
2
3
X8  
F
X2  
4
G4  
G2  
217  
220  
313A  
TIG  
MODE  
SCR2  
REMOTE  
5
T1  
J4  
6
POLARITY SWITCH MICRO SWITCH  
L1  
7
AC A-C, D-E, B-F  
DC+ B-D, C-E, A-F, G-H  
DC- B-D, A-E, C-F, G-H  
OPEN  
CLOSED  
CLOSED  
8
9
218  
216  
217  
G3  
232  
FRONT GANG  
D
10  
115VAC  
MICRO-SWITCH  
REAR GANG  
C8  
CB1  
15A  
C9  
D2  
B
S2A  
NO  
H
W
B
1
6
E
F
NC  
233  
A
SCR3  
331  
332  
333  
334  
335  
(STICK)  
(AUTO BAL)  
(REMOTE)  
(THERMAL)  
+
(P. FLOW)  
233B  
8
231  
G
-
W
B
2
4
2
-
-
W
-
W
-
W
+
B
+
+
B
+
220  
C
R
G
G
G
7
( - )  
Y
W
B
B
B
W
3
B
W
J10  
1
0
50A  
8
POS  
D1  
CR4  
B
W
B
4
X2  
SCR4  
CR4  
6
9
G4  
W
B
252  
253  
5
1
9
263  
234  
10  
S2  
SV2  
L7  
WATER VALVE  
(OPTIONAL)  
2
N.F.  
269  
270  
271  
220B  
POLARITY  
SWITCH  
(REAR VIEW, SHOWN  
IN AC POSITION)  
10  
1
3
2
5
4
6
3
N.D.  
11  
N.C.  
J7  
C1,C2  
C4,C5  
C6  
POWER FACTOR CAPACITORS, 50/460 (OPTIONAL)  
BY-PASS CAPACITORS, .0047  
HIGH VOLTAGE CAPACITOR, .0015/12kV  
PHASE SHIFT CAPACITOR, 15uF/250VAC  
HIGH FREQ PROTECTION CAPACITORS, .22/400  
CIRCUIT BREAKER, 15 AMP  
CIRCUIT BREAKER, 5 AMP  
12V DC RELAY COIL  
FREE WHEELING DIODE  
BACKGROUND DIODE  
OUTPUT INDUCTOR (CHOKE)  
HIGH FREQ INDUCTORS  
RF TOROID CHOKES  
OUTPUT CONTROL POTENTIOMETER, 10K  
BALANCE CONTROL POTENTIOMETER, 10K  
POST FLOW POTENTIOMETER, 10K  
MIN OUTPUT POTENTIOMETER, 10K  
PHASE SHIFT RESISTOR, 200/100  
HOLDING RESISTOR, 50/225  
265  
266  
262  
263  
213  
214  
6
12  
5
ADVANCED CONTROL PANEL  
(OPTIONAL)  
J3  
J11  
BACKGROUND  
RECTIFIER  
271A  
R7  
C7  
13  
4
1
1
2
2
3
3
4
4
5
6
7
7
8
8
9 10  
DOWN SLOPE  
BACKGROUND  
ON TIME  
FREQ  
C8,C9  
CB1  
CB2  
CR4  
D1  
D2  
L1  
L2,L3  
L4 -L13  
R1  
R2  
R3  
R4  
R5  
R6  
R7  
R8  
R9  
269  
267  
268  
R8  
271  
270  
14  
7
OR  
J3  
R11  
N.C.  
R12  
R10  
R9  
201  
204  
262  
263  
L13  
15  
401C  
W209  
R210  
8
16  
201  
204  
W209  
R210  
5
6
9 10  
220B  
220A  
401  
402  
403  
404  
405  
406  
407  
408  
409  
410  
411  
W
1
2
L10  
3
(PULSE ON)  
4-STEP  
ON  
4
5
-
+
B
G
6
214  
RESISTOR, 20/100  
RESISTOR, 5/50  
7
W
S
FAN  
8
9
10  
11  
12  
FREQ CONTROL POTENTIOMETER, 10K  
ON TIME CONTROL POTENTIOMETER, 10K  
BACKGROUND POTENTIOMETER, 10K  
DOWN SLOPE POTENTIOMETER, 10K  
INPUT POWER SWITCH  
213  
R10  
R11  
R12  
S1  
S2  
S2A  
OFF  
2-STEP  
C
TRANSFORMER  
PRIMARY  
THERMOSTAT  
TRIGGER  
PULSE  
TRANSFORMER  
SECONDARY  
THERMOSTAT  
BYPASS/  
STABILIZER  
PC BOARD  
J1  
260  
POLARITY SWITCH  
MICROSWITCH ON POLARITY SWITCH  
233A  
1
2
3
4
5
6
7
8
9 10  
1
2
3
4
5
7
SCR1,2,3,4 MAIN POWER SCR'S  
SV1  
SV2  
T1  
T2  
T3  
GAS SOLENOID VALVE, 115VAC  
WATER SOLENOID VALVE, 115VAC (OPTIONAL)  
MAIN TRANSFORMER  
HIGH VOLTAGE TRANSFORMER  
HIGH FREQ TRANSFORMER  
GAS VALVE  
235  
J2  
SV1  
233A  
231A  
231D  
J5A  
231E  
E
F
6
8
L11  
COMPONENT VALUE  
UNITS:  
RESISTORS:  
LEAD COLORING CODE:  
N.B.  
L9  
PROTECTION PCB  
B-BLACK  
U-BLUE  
W-WHITE  
Y-YELLOW  
N.A. CONNECTION IS PIN TO PIN BETWEEN J23 AND J5.  
N.B. ROBOTIC INTERFACE CONNECTION.  
N.C. REMOVE JUMPER PLUG IN J3 WHEN INSTALLING  
TIG OPTION PC BOARD.  
N.D. DISCONNECT JUMPER LEAD BETWEEN PIN 1 AND  
PIN 2 IN J3 TO DOUBLE PREFLOW & POSTFLOW TIMES.  
N.E. DISPLAY TOGGLE SHOWN IN MIN AMP POSITION.  
N.F. PLUGS INTO LOWER SWITCHED RECEPTACLE.  
L2  
G-GREEN  
O-ORANGE  
R-RED  
OHMS/WATTS  
C6  
S
1
CAPACITORS:  
MFD/VOLTS  
A
B
C
D
E
F
A
B
C
D
E
F
115VAC  
2
3
5
6
4
260  
235  
T3  
R6  
SPARK  
GAP  
1
2
3
4
5
7
6
8
1
2
3
4
5
7
T2  
J12  
A
B
C
D
E
F
4
1
2
3
6
5
CONNECTOR PIN NUMBERS:  
L8  
236  
233A  
284  
285  
EXAMPLE: THIS IS PIN 7  
0F CONNECTOR J5  
J23  
J22  
1 2 3  
7
J5  
10K A-B  
AT MINIMUM  
L3  
N.A.  
F
237  
6
8
14  
8
1 2 3  
8
OPTIONAL  
REMOTE  
FRONT  
ELECTRODE  
WORK  
J5  
REMOTE  
RECEPTACLE  
LATCH  
R5  
TM  
C7  
VIEW OF CONNECTOR ON PC BOARD  
ELECTRICAL SYMBOLS PER E1537.  
AMPTROL  
ARC STARTER AS'BLY  
REAR  
ELECTRODE  
236B  
B
G4031-2  
NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual. The wiring diagram specific to your code is pasted inside one of the enclosure panels of your machine.  
®
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
G-5  
G-5  
ELECTRICAL DIAGRAMS  
WIRING DIAGRAM - ENTIRE MACHINE - CODE 11158 (G5692)  
460 V  
PRECISION TIG 275 WIRING DIAGRAM  
CONNECT STRAP TO HIGH (H4) (AS SHOWN)  
CONNECTER LA BRIDE SUR HAUT (H4)  
(COMME ILLUSTRÉ)  
L1 (U)  
L2 (V)  
H1  
SCHÉMA DE CÂBLAGE DIAGRAMAS DE CABLEADO  
CONTROL PANEL (VIEWED FROM REAR)  
PANNEAU DE COMMANDE (VIEWED FROM REAR)  
PANEL DE CONTROL (VISTO DESDE ATRÁS)  
N.A. CONNECTION IS PIN TO PIN BETWEEN J23 AND J5.  
SUJETADOR DE CONEXIÓN A ALTO (H4)  
N.A. CONNEXION CONTACT-CONTACT ENTRE J23 ET J5  
N.B. CONNEXION INTERFACE ROBOTIQUE  
N.B. ROBOTIC INTERFACE CONNECTION.  
(COMO SE MUESTRA)  
S1  
230 V  
N.C. REMOVE JUMPER PLUG IN J3 WHEN INSTALLING  
TIG OPTION PC BOARD.  
115VAC  
N.C. ENLEVER LA FICHE CAVALIER EN J3 QUAND ON INSTALLE LE CI EN  
OPTION TIG  
CONNECT STRAP TO MID (H3)  
CONNECTER LA BRIDE SUR MOYEN (H3)  
SUJETADOR DE CONEXIÓN A MEDIO (H3)  
C8  
C9  
N.D. DISCONNECT JUMPER LEAD BETWEEN PIN 1 AND  
PIN 2 IN J3 TO DOUBLE PREFLOW & POSTFLOW TIMES.  
N.E. DISPLAY TOGGLE SHOWN IN MIN AMP POSITION.  
N.F. PLUGS INTO LOWER SWITCHED RECEPTACLE.  
C1  
C2  
METER  
1
2
3
4
N.D. DÉCONNECTER LE CÂBLE DU CAVALIER ENTRE LES CONTACTS 1 ET  
2 DANS J3 POUR DOUBLER TEMPS DE PRÉGAZ ET POSTGAZ.  
N.E. AFFICHE LA BASCULE ILLUSTRÉE EN POSITION A MINIMUM.  
N.F. SE BRANCHE LA PRISE À INTERRUPTEUR INFÉRIEURE.  
344  
347  
COMPTEUR  
MEDIDOR  
H4  
H3  
H2  
208 V  
A
233B  
8
231  
CONNECT STRAP TO LOW (H2)  
CONNECTER LA BRIDE SUR BAS (H2)  
SUJETADOR DE CONEXIÓN A BAJO(H2)  
345  
343  
L1 (U)  
251  
H1  
4
2
MID  
J7  
C5  
C4  
S3  
HIGH  
LOW  
250  
1
CONTROL PC BOARD  
CR4  
N.A. LA CONEXIÓN ES DE PIN A PIN ENTRE J23 Y J5.  
N.B. CONEXIÓN DE LA INTERFAZ ROBÓTICA.  
2
6
316D  
CI DE COMMANDE  
TABLEAU DE  
343  
344  
345  
346  
347  
3
4
5
6
7
8
234  
L2 (V)  
COM  
N.C. REMUEVA EL CONECTOR DE PUENTE EN J3 CUANDO INSTALE LA  
TARJETA DE PC TIG OPCIONAL.  
TARJETA ELECTRONICA  
DE CONTROL  
X5  
J13  
J8  
GROUND  
TERRE  
S
F
RECONNECT PANEL  
PANNEAU DE RECONNEXION  
PANEL DE RECONEXIÓN  
346  
L5  
63.5VAC  
C1,C2  
C4,C5  
C6  
C7  
C8,C9  
CB1  
CR4  
D1  
L1  
L2,L3  
L4 -L13  
R5  
POWER FACTOR CAPACITORS, 50/460  
BY-PASS CAPACITORS, .0047  
HIGH VOLTAGE CAPACITOR, .0015/12kV  
PHASE SHIFT CAPACITOR, 15uF/250VAC  
HIGH FREQ PROTECTION CAPACITORS, .22/400  
CIRCUIT BREAKER, 15 AMP  
H2 (208V)  
H3 (230V)  
H4 (460V)  
N.D. DESCONECTE EL CABLE DEL PUENTE ENTRE EL PIN 1 Y PIN 2 EN J3  
PARA DUPLICAR LOS TIEMPOS DE PRE Y POSTFLUJO.  
N.E. EL INTERRUPTOR DE PALANCA DE LA PANTALLA SE MUESTRA EN LA  
POSICIÓN MÍNIMA DE AMPERIOS.  
TIERRA  
X6  
X3  
DISPLAY  
AFFICHAGE  
PANTALLA  
231  
231A  
S
A LA TERRE SELON LE CODE  
ÉLECTRIQUE NATIONAL  
TO GROUND PER  
NATIONAL  
1
X9  
115VAC  
S
F
MIN. OUTPUT  
RENDEMENT  
SALIDA  
2
3
4
5
6
201  
204  
N.E.  
A TIERRA CONFORME EL CÓDIGO  
ELÉCTRICO NACIONAL  
F
18VAC  
X10  
X4  
232  
ELECTRICAL CODE  
R4  
N.F. ENCHUFES EN RECEPTÁCULO CONMUTADO INFERIOR.  
12V DC RELAY COIL  
FREE WHEELING DIODE  
N.F.  
X1  
S
OUTPUT INDUCTOR (CHOKE)  
HIGH FREQ INDUCTORS  
1
2
W 221  
J6  
X7  
R 222  
SV2  
S
F
78VAC  
X2  
216A  
216  
W209  
R210  
RF TOROID CHOKES  
20VAC  
311  
312  
313  
314  
315  
316  
317  
318  
319  
320  
321  
322  
L4  
1
BALANCE  
PHASE SHIFT RESISTOR, 200/100  
HOLDING RESISTOR, 50/225  
L6  
2
3
X8  
T1 F  
313B  
ÉQUILIBRE  
BALANCEADO  
X1  
R6  
R7A, R7B,  
STICK  
MAX OUTPUT  
RENDEMENT  
SALIDA  
ÉLECTRODE  
VARILLA  
POST FLOW  
4
5
ÉCOULEMENT DE POTEA  
FLUJO DEL POSTE  
LOCAL  
RESISTOR, 5/50  
R7C, R7D,  
R8A, R8B  
S1  
SCR1  
L12  
6
J9  
( + )  
7
G1  
INPUT POWER SWITCH  
POLARITY SWITCH  
8
1
G1  
G3  
S2  
218  
R2  
R1  
POS  
R3  
9
2
3
S2A  
MICROSWITCH ON POLARITY SWITCH  
MENU SWITCH  
10  
11  
12  
218A  
G2  
S3  
4
G4  
G2  
313A  
5
SCR1,2,3,4 MAIN POWER SCR'S  
SCR2  
TIG  
REMOTE  
J4  
S2  
S2A  
6
217  
220  
SV1  
SV2  
T1  
T2  
T3  
GAS SOLENOID VALVE, 115VAC  
WATER SOLENOID VALVE, 115VAC (OPTIONAL)  
MAIN TRANSFORMER  
HIGH VOLTAGE TRANSFORMER  
HIGH FREQ TRANSFORMER  
L1  
À DISTANCE  
REMOTO  
OPEN OUVERT ABIERTO  
AC A-C, D-E, B-F  
7
DC+ B-D, C-E, A-F, G-H CLOSED FERMÉ CERRADO  
DC- B-D, A-E, C-F, G-H CLOSED FERMÉ CERRADO  
8
217A  
217  
9
218  
216  
10  
D
B
CB1  
15A  
S2A  
NO  
G3  
REMOTE  
POST FLOW  
THERMAL  
BALANCE  
C1,C2  
C4,C5  
C6  
CONDENSATEURS FACTEUR DE PUISSANCE, 50/460  
CAPACITORES DE FACTOR DE POTENCIA, 50/460  
CONDENSATEURS DÉRIVATION , .0047  
H
W
B
1
6
E
NC  
STICK  
VARILLA  
THERMIQUE  
A
À DISTANCE  
ÉCOULEMENT DE POTEA  
SCR3  
( - )  
ÉQUILIBRE  
331  
332  
333  
334  
335  
233  
ÉLECTRODE  
REMOTO  
TERMAL  
-
FLUJO DEL POSTE  
+
BALANCEADO  
G
F
W
B
2
233A  
-
-
-
-
+
+
+
+
220  
C
R
G
G
G
7
Y
CAPACITORES DE DERIVACIÓN, .0047  
W
B
B
B
B
B
W
W
W
W
3
B
W
CONDENSATEUR HAUTE TENSION, .0015/12kV  
CAPACITOR DE ALTO VOLTAJE, .0015/12kV  
CONDENSATEUR, DÉPHASAGE, 15Mf/250VCA  
CAPACITOR DE CAMBIO DE FASE 15uf/250VCA  
CONDENSATEURS DE PROTECTION HF, .22/400  
CAPACITORES DE PROTECCIÓN CONTRA ALTA  
J10  
J7  
1
0
8
POS  
D1  
CR4  
B
W
B
4
X2  
SCR4  
C7  
9
G4  
W
B
252  
253  
5
1
9
263  
10  
C8,C9  
S2  
L7  
2
269  
FRECUENCIA, .22/400  
DISJONCTEUR, 15 AMP  
10  
3
270  
1
3
2
5
4
6
CB1  
CR4  
D1  
271  
ADVANCED CONTROL PANEL (OPTIONAL)  
N.D.  
N.C.  
229A  
11  
INTERRUPTOR AUTOMÁTICO, 15 AMPS  
BOBINE RELAI DE 12V CC  
BOBINA DE RELEVADOR DE 12V DE DC  
DIODE ROUE LIBRE  
DIODO DE RUEDA LIBRE  
INDUCTEUR DE SORTIE (STARTER)  
INDUCTOR DE SALIDA (ESTABILIZADOR)  
INDUCTANCES HF  
INDUCTORES DE ALTA FRECUENCIA  
STARTERS TOROÏDE FRÉQUENCE RADIO  
ESTABILIZADORES TOROIDAL RF  
RÉSISTANCE DÉPHASAGE, 200/100  
RESISTOR DE CAMBIO DE FASE, 200/100  
RÉSISTANCE DE MAINTIEN, 50/225  
RESISTOR DE SOSTENIMIENTO, 50/225  
PANNEAU DE COMMANDE AVANCÉ (OPTION)  
PANEL DE CONTROL AVANZADO (OPCIONAL)  
217A  
265  
266  
262  
263  
213  
214  
6
J3  
12  
BACKGROUND  
ARRIÈRE PLAN  
FONDO  
ON TIME  
J11  
DOWN SLOPE  
VERS LE BAS PENTE  
ABAJO CUESTA  
218A  
271A  
5
13  
4
14  
7
15  
R7C  
R7A  
R7B  
229  
À L 'HEURE  
EL TIEMPO  
1
1
2
2
3
4
4
5
6
7
7
8
8
9 10  
R7D  
FREQ  
L1  
269  
R8A  
271  
L2,L3  
L4 -L13  
R5  
OR  
N.C.  
R12  
R11  
201  
R9  
R10  
268  
270  
L13  
J3  
204  
262  
401C  
W209  
R210  
8
16  
263  
3
5
6
9 10  
201  
229A  
229  
204  
J1  
W209  
R210  
R6  
401  
402  
403  
404  
405  
406  
407  
408  
409  
410  
411  
W
1
2
216A  
L10  
SPOT  
R7A,R7B,  
4 STEP  
TACHE  
PUNTO  
3
4 TEMPS  
4 PASO  
RÉSISTANCE, 5/50, RESISTORES, 5/50  
R7C,R7D,  
R8A, R8B  
S1  
-
+
-
4
B
W
R
G
GND6  
5
SPOT  
INTERRUPTEUR DE PUISSANCE D’ENTRÉE  
INTERRUPTOR DE ENERGÍA DE ENTRADA  
INTERRUPTEUR DE POLARITÉ  
INTERRUPTOR DE POLARIDAD  
MICRORUPTEUR SUR SÉLECTEUR DE POLARITÉ  
MICROINTERRUPTOR EN EL INTERRUPTOR DE  
TACHE  
6
214  
213  
PUNTO  
7
S
FAN  
8
+
B
BYPASS/STABILIZER PC BOARD  
CI DÉRIVATION/STABILISATEUR  
S2  
9
PULSE  
VENTILATEUR  
VENTILADOR  
10  
11  
12  
W
PULSE  
TARJETA ELECTRONICA DE  
S2A  
2 STEP  
T1 SECONDARY  
THERMOSTAT  
T1 SECONDAIRE  
THERMOSTAT  
TERMOSTATO  
SECUNDARIO  
DEL T1  
PULSÉ  
T1 PRIMARY  
C
PULSÉ  
2 TEMPS  
2 PASO  
PULSACIÓN  
DERIVACION /  
THERMOSTAT  
T1 PRIMAIRE  
PULSACIÓN  
ESTABILIZADOR  
POLARIDAD  
413  
W
1
J20  
THERMOSTAT  
TERMOSTATO  
PRIMARIO DEL T1  
260  
S3  
INTERRUPTEUR MENU  
INTERRUPTOR DE MENÚ  
SCR1,2,3,4 REDRESSEURS DE PUISSANCE PRINCIPAUX  
SCR'S DE ALIMENTACIÓN PRINCIPAL  
2
233A  
1
2
3
4
5
6
7
8
9 10  
1
2
3
4
5
7
J2  
SV1  
SV1  
SV2  
T1  
SOUPAPE SOLÉNOÏDE DE GAZ, 115 VAC  
VÁLVULA DE SOLENOIDE DE GAS, 115 VCA  
SOUPAPE SOLÉNOÏDE À EAU, 115 VAC  
VÁLVULA DE SOLENOIDE DE AGUA, 115 VCA  
TRANSFORMATEUR PRINCIPAL  
235  
233A  
231A  
231D  
J5A  
231E  
E
F
6
L11  
8
COMPONENT VALUE UNITS:  
UNIDADES DE VALOR DE COMPONENTES:  
RESISTORES: OHMS/WATTS  
N.B.  
L9  
TRANSFORMADOR PRINCIPAL  
PROTECTION PCB  
CI PROTECTION  
RESISTORS: OHMS/WATTS  
CAPACITORS: MFD/VOLTS  
T2  
TRANSFORMATEUR HAUTE TENSION  
TRANSFORMADOR DE ALTO VOLTAJE  
TRANSFORMATEUR HAUTE FRÉQUENCE  
TRANSFORMADOR DE ALTA FRECUENCIA  
CAPACITORES: MFD/VOLTIOS  
L2  
C6  
PCB DE PROTECCIÓN  
S
UNITÉS DE VALEUR DES COMPOSANTS:  
1
A
B
C
D
E
F
A
B
C
D
E
F
115VAC  
237  
RÉSISTANCES: OHMS/WATTS  
T3  
SPARK GAP  
2
3
5
6
4
260  
235  
T3  
R6  
1
2
3
4
5
7
6
8
1
2
3
4
5
7
CONDENSATEURS: MFD/VOLTS  
T2  
ÉCLATEUR  
ABERTURA  
DE CHISPA  
J12  
A
B
C
D
E
F
4
1
2
3
6
5
CONNECTOR PIN NUMBERS: NOMBRE DE CONTACTS CONNECTEURS  
NÚMEROS DE PINES DE CONECTORES:  
L8  
236  
284  
285  
J23  
J22  
LEAD COLORING CODE:  
233A  
J5  
EXAMPLE: THIS IS PIN 1  
CODE DE COULEUR DES CÂBLES:  
10K A-B  
MINIMUM  
1 2 3  
7
L3  
N.A.  
F
0F CONNECTOR J5  
CÓDIGO DE COLORES DE CABLES:  
EXEMPLE: C'EST LE CONTACT 1  
DU CONNECTEUR J5  
1 2 3  
8
W-WHITE  
BLANC  
6
R-RED  
B-BLACK  
FRONT  
WORK  
PIÈCE  
ROUGE  
14  
8
8
NOIR  
J5  
REMOTE  
RECEPTACLE  
ELECTRODE  
EJEMPLO: ESTE ES EL PIN 1 DEL  
CONECTOR J5  
BLANCO  
ROJO  
B-BLUE  
BLEU  
VIEW OF CONNECTOR ON PC BOARD  
VUE DES CONNECTEURS SUR CI  
NEGRO  
PRISE À DISTANCE  
R5  
TM  
ÉLECTRODE AVANT  
C7  
Y-YELLOW  
G-GREEN  
VERT  
AMPTROL  
TRABAJO  
RECEPTÁCULO REMOTO  
REAR  
JAUNE  
ARC STARTER AS'BLY  
ENSEMBLE DÉMARREUR D'ARC  
ENSAMBLE DE ARRANCADOR DE  
ARCO  
ELECTRODO FRONTAL  
VISTA DEL CONECTOR EN LA  
TARJETA ELECTRONICA  
AMARILLO  
ELECTRODE  
AZUL  
VERDE  
ELECTRICAL SYMBOLS PER E1537.  
236B  
O-ORANGE  
NARANJA  
ÉLECTRODE ARRIÈRE  
SYMBOLES ÉLECTRIQUES SELON E1537  
A
R
SÍMBOLOS ELÉCTRICOS CONFORME A E1537  
ELECTRODO POSTERIOR  
G5692PRINT  
CLEVELAND , OHIO  
NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual. The wiring diagram specific to your code is pasted inside one of the enclosure panels of your machine.  
®
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
G-6  
G-6  
ELECTRICAL DIAGRAMS  
WIRING DIAGRAM - ENTIRE MACHINE - CODE 11159 (G5692-1)  
575 V  
PRECISION TIG 275 WIRING DIAGRAM  
CONNECT STRAP TO HIGH (H4) (AS SHOWN)  
CONNECTER LA BRIDE SUR HAUT (H4)  
(COMME ILLUSTRÉ)  
L1 (U)  
L2 (V)  
H1  
SCHÉMA DE CÂBLAGE DIAGRAMAS DE CABLEADO  
CONTROL PANEL (VIEWED FROM REAR)  
SUJETADOR DE CONEXIÓN A ALTO (H4)  
(COMO SE MUESTRA)  
N.A. CONNECTION IS PIN TO PIN BETWEEN J23 AND J5.  
PANNEAU DE COMMANDE (VIEWED FROM REAR)  
PANEL DE CONTROL (VISTO DESDE ATRÁS)  
N.A. CONNEXION CONTACT-CONTACT ENTRE J23 ET J5  
N.B. ROBOTIC INTERFACE CONNECTION.  
232  
CB1  
15A  
115VAC  
N.B. CONNEXION INTERFACE ROBOTIQUE  
S1  
460 V  
N.C. REMOVE JUMPER PLUG IN J3 WHEN INSTALLING  
TIG OPTION PC BOARD.  
C8  
C9  
N.C. ENLEVER LA FICHE CAVALIER EN J3 QUAND ON INSTALLE LE CI EN  
OPTION TIG  
CONNECT STRAP TO LOW (H2)  
CONNECTER LA BRIDE SUR BAS (H2)  
SUJETADOR DE CONEXIÓN A BAJO (H2)  
N.D. DISCONNECT JUMPER LEAD BETWEEN PIN 1 AND  
PIN 2 IN J3 TO DOUBLE PREFLOW & POSTFLOW TIMES.  
N.E. DISPLAY TOGGLE SHOWN IN MIN AMP POSITION.  
N.F. PLUGS INTO LOWER SWITCHED RECEPTACLE.  
233  
METER  
COMPTEUR  
MEDIDOR  
1
2
3
4
N.D. DÉCONNECTER LE CÂBLE DU CAVALIER ENTRE LES CONTACTS 1 ET  
2 DANS J3 POUR DOUBLER TEMPS DE PRÉGAZ ET POSTGAZ.  
N.E. AFFICHE LA BASCULE ILLUSTRÉE EN POSITION A MINIMUM.  
N.F. SE BRANCHE LA PRISE À INTERRUPTEUR INFÉRIEURE.  
344  
347  
H4  
H2  
233B  
8
231  
A
4
2
L1 (U)  
345  
343  
C1  
C2  
MID  
J7  
250  
LOW  
C5  
C4  
C1,C2  
C4,C5  
C6  
POWER FACTOR CAPACITORS, 50/460  
S2  
HIGH  
CR4  
6
1
251  
H1  
BY-PASS CAPACITORS, .0047  
HIGH VOLTAGE CAPACITOR, .0015/12kV  
PHASE SHIFT CAPACITOR, 15uF/250VAC  
HIGH FREQ PROTECTION CAPACITORS, .22/400  
CIRCUIT BREAKER, 15 AMP  
CONTROL PC BOARD  
N.A. LA CONEXIÓN ES DE PIN A PIN ENTRE J23 Y J5.  
N.B. CONEXIÓN DE LA INTERFAZ ROBÓTICA.  
2
316D  
234  
CI DE COMMANDE  
343  
344  
345  
346  
347  
3
TABLEAU DE  
C7  
L2 (V)  
4
COM  
N.C. REMUEVA EL CONECTOR DE PUENTE EN J3 CUANDO INSTALE LA  
TARJETA DE PC TIG OPCIONAL.  
TARJETA ELECTRONICA  
5
6
7
8
J13  
J8  
C8,C9  
CB1  
GROUND  
TERRE  
RECONNECT PANEL  
PANNEAU DE RECONNEXION  
PANEL DE RECONEXIÓN  
346  
DE CONTROL  
L5  
TIERRA  
N.D. DESCONECTE EL CABLE DEL PUENTE ENTRE EL PIN 1 Y PIN 2 EN J3  
PARA DUPLICAR LOS TIEMPOS DE PRE Y POSTFLUJO.  
N.E. EL INTERRUPTOR DE PALANCA DE LA PANTALLA SE MUESTRA EN LA  
POSICIÓN MÍNIMA DE AMPERIOS.  
CR4  
D1  
L1  
12V DC RELAY COIL  
DISPLAY  
AFFICHAGE  
PANTALLA  
X5  
FREE WHEELING DIODE  
OUTPUT INDUCTOR (CHOKE)  
HIGH FREQ INDUCTORS  
S
F
63.5VAC  
H2 (460V)  
H4 (575V)  
1
TO GROUND PER  
MIN. OUTPUT  
RENDEMENT  
SALIDA  
X6  
X3  
115VAC  
A LA TERRE SELON LE CODE  
ÉLECTRIQUE NATIONAL  
L2,L3  
L4 -L13  
R5  
2
3
4
5
6
NATIONAL  
RF TOROID CHOKES  
231  
R4  
ELECTRICAL CODE  
S
F
N.F. ENCHUFES EN RECEPTÁCULO CONMUTADO INFERIOR.  
A TIERRA CONFORME EL CÓDIGO  
ELÉCTRICO NACIONAL  
PHASE SHIFT RESISTOR, 200/100  
HOLDING RESISTOR, 50/225  
N.E.  
231A  
X9  
S
F
R6  
201  
204  
18VAC  
X10  
232  
X4  
R7A, R7B,  
1
2
W 221  
J6  
RESISTOR, 5/50  
R7C, R7D,  
R8A, R8B  
S1  
R 222  
216A  
216  
X1  
311  
312  
313  
314  
315  
316  
317  
318  
319  
320  
321  
322  
L4  
1
S
BALANCE  
L6  
INPUT POWER SWITCH  
POLARITY SWITCH  
MICROSWITCH ON POLARITY SWITCH  
MENU SWITCH  
2
3
ÉQUILIBRE  
BALANCEADO  
X1  
313B  
X7  
S2  
STICK  
N.F.  
S
F
78VAC  
X2  
W209  
R210  
MAX OUTPUT  
RENDEMENT  
SALIDA  
ÉLECTRODE  
VARILLA  
POST FLOW  
4
20VAC  
S2A  
5
ÉCOULEMENT DE POTEA  
FLUJO DEL POSTE  
LOCAL  
S3  
X8  
T1 F  
SCR1  
L12  
6
J9  
SCR1,2,3,4 MAIN POWER SCR'S  
+ ( )  
7
G1  
SV1  
SV2  
T1  
T2  
T3  
GAS SOLENOID VALVE, 115VAC  
WATER SOLENOID VALVE, 115VAC (OPTIONAL)  
MAIN TRANSFORMER  
HIGH VOLTAGE TRANSFORMER  
HIGH FREQ TRANSFORMER  
8
1
G1  
G3  
SV2  
L1  
218  
218A  
G2  
R2  
R1  
R3  
POS  
9
2
3
10  
11  
12  
4
G4  
G2  
313A  
5
SCR2  
TIG  
REMOTE  
J4  
S2  
S2A  
6
217  
220  
À DISTANCE  
REMOTO  
OPEN OUVERT ABIERTO  
AC A-C, D-E, B-F  
7
C1,C2  
C4,C5  
C6  
CONDENSATEURS FACTEUR DE PUISSANCE, 50/460  
CAPACITORES DE FACTOR DE POTENCIA, 50/460  
CONDENSATEURS DÉRIVATION , .0047  
DC+ B-D, C-E, A-F, G-H CLOSED FERMÉ CERRADO  
DC- B-D, A-E, C-F, G-H CLOSED FERMÉ CERRADO  
217A  
217  
8
9
218  
216  
10  
CAPACITORES DE DERIVACIÓN, .0047  
D
B
CONDENSATEUR HAUTE TENSION, .0015/12kV  
CAPACITOR DE ALTO VOLTAJE, .0015/12kV  
CONDENSATEUR, DÉPHASAGE, 15Mf/250VCA  
CAPACITOR DE CAMBIO DE FASE 15uf/250VCA  
CONDENSATEURS DE PROTECTION HF, .22/400  
CAPACITORES DE PROTECCIÓN CONTRA ALTA  
S2A  
NO  
POST FLOW  
G3  
THERMAL  
REMOTE  
BALANCE  
H
W
B
1
6
E
NC  
THERMIQUE  
STICK  
VARILLA  
ÉCOULEMENT DE POTEA  
A
À DISTANCE  
SCR3  
ÉQUILIBRE  
331  
332  
333  
334  
335  
C7  
TERMAL  
-
ÉLECTRODE  
REMOTO  
FLUJO DEL POSTE  
+
BALANCEADO  
G
F
W
B
2
-
-
-
-
+
+
+
+
220  
C
R
G
G
G
7
( - )  
Y
C8,C9  
W
B
B
B
B
B
W
W
W
W
3
B
W
J10  
J7  
1
0
8
POS  
D1  
CR4  
B
FRECUENCIA, .22/400  
W
B
4
X2  
SCR4  
CB1  
CR4  
D1  
DISJONCTEUR, 15 AMP  
INTERRUPTOR AUTOMÁTICO, 15 AMPS  
BOBINE RELAI DE 12V CC  
BOBINA DE RELEVADOR DE 12V DE DC  
DIODE ROUE LIBRE  
DIODO DE RUEDA LIBRE  
INDUCTEUR DE SORTIE (STARTER)  
INDUCTOR DE SALIDA (ESTABILIZADOR)  
INDUCTANCES HF  
INDUCTORES DE ALTA FRECUENCIA  
STARTERS TOROÏDE FRÉQUENCE RADIO  
ESTABILIZADORES TOROIDAL RF  
RÉSISTANCE DÉPHASAGE, 200/100  
RESISTOR DE CAMBIO DE FASE, 200/100  
RÉSISTANCE DE MAINTIEN, 50/225  
RESISTOR DE SOSTENIMIENTO, 50/225  
9
G4  
W
B
252  
253  
5
1
9
263  
10  
S2  
L7  
2
269  
10  
3
270  
1
3
2
5
4
6
271  
ADVANCED CONTROL PANEL (OPTIONAL)  
N.D.  
229A  
11  
L1  
PANNEAU DE COMMANDE AVANCÉ (OPTION)  
PANEL DE CONTROL AVANZADO (OPCIONAL)  
N.C.  
265  
266  
262  
263  
213  
214  
217A  
6
L2,L3  
L4 -L13  
R5  
J3  
12  
BACKGROUND  
ARRIÈRE PLAN  
FONDO  
ON TIME  
J11  
DOWN SLOPE  
218A  
271A  
5
13  
4
14  
7
15  
R7C  
R7A  
R7B  
À L 'HEURE  
EL TIEMPO  
VERS LE BAS PENTE  
ABAJO CUESTA  
1
1
2
2
3
3
4
5
6
7
7
8
8
9 10  
R7D  
FREQ  
269  
R8A  
271  
270  
OR  
N.C.  
R11  
R10  
R9  
R12  
201  
268  
R6  
229  
L13  
J3  
262  
204  
263  
401C  
W209  
R210  
8
16  
R7A,R7B,  
4
5
6
9 10  
201  
RÉSISTANCE, 5/50, RESISTORES, 5/50  
R7C,R7D,  
R8A, R8B  
S1  
229A  
229  
204  
W209  
R210  
J1  
INTERRUPTEUR DE PUISSANCE D’ENTRÉE  
INTERRUPTOR DE ENERGÍA DE ENTRADA  
INTERRUPTEUR DE POLARITÉ  
401  
402  
403  
404  
405  
406  
407  
408  
409  
410  
411  
W
1
2
216A  
L10  
SPOT  
4 STEP  
S2  
TACHE  
PUNTO  
3
4 TEMPS  
4 PASO  
INTERRUPTOR DE POLARIDAD  
-
+
-
4
B
W
R
G
GND6  
S2A  
MICRORUPTEUR SUR SÉLECTEUR DE POLARITÉ  
5
SPOT  
TACHE  
6
MICROINTERRUPTOR EN EL INTERRUPTOR DE  
214  
213  
T1 PRIMARY  
THERMOSTAT  
T1 PRIMAIRE  
THERMOSTAT  
PUNTO  
7
POLARIDAD  
S
FAN  
BYPASS/STABILIZER PC BOARD  
CI DÉRIVATION/STABILISATEUR  
8
+
B
S3  
INTERRUPTEUR MENU  
INTERRUPTOR DE MENÚ  
SCR1,2,3,4 REDRESSEURS DE PUISSANCE PRINCIPAUX  
SCR'S DE ALIMENTACIÓN PRINCIPAL  
9
PULSE  
VENTILATEUR  
VENTILADOR  
10  
11  
12  
W
PULSE  
2 STEP  
PULSÉ  
T1 SECONDARY  
THERMOSTAT  
T1 SECUNDARIO  
THERMOSTAT  
C
TARJETA ELECTRONICA DE  
DERIVACIÓN /  
PULSÉ  
2 TEMPS  
2 PASO  
PULSACIÓN  
PULSACIÓN  
SV1  
SV2  
T1  
SOUPAPE SOLÉNOÏDE DE GAZ, 115 VAC  
VÁLVULA DE SOLENOIDE DE GAS, 115 VCA  
SOUPAPE SOLÉNOÏDE À EAU, 115 VAC  
VÁLVULA DE SOLENOIDE DE AGUA, 115 VCA  
TRANSFORMATEUR PRINCIPAL  
ESTABILIZADOR  
413  
W
1
J20  
260  
2
233A  
1
2
3
4
5
6
7
8
9 10  
1
2
3
4
5
7
J2  
SV1  
TRANSFORMADOR PRINCIPAL  
235  
233A  
231A  
T2  
TRANSFORMATEUR HAUTE TENSION  
TRANSFORMADOR DE ALTO VOLTAJE  
TRANSFORMATEUR HAUTE FRÉQUENCE  
TRANSFORMADOR DE ALTA FRECUENCIA  
231D  
J5A  
231E  
E
F
6
T3  
L11  
8
COMPONENT VALUE UNITS:  
RESISTORS: OHMS/WATTS  
CAPACITORS: MFD/VOLTS  
UNIDADES DE VALOR DE COMPONENTES:  
RESISTORES: OHMS/WATTS  
N.B.  
L9  
PROTECTION PCB  
CI PROTECTION  
CAPACITORES: MFD/VOLTIOS  
L2  
C6  
PCB DE PROTECCIÓN  
S
UNITÉS DE VALEUR DES COMPOSANTS:  
1
A
B
C
D
E
F
A
B
C
D
E
F
115VAC  
237  
RÉSISTANCES: OHMS/WATTS  
2
3
5
6
4
260  
235  
T3  
R6  
SPARK GAP  
ÉCLATEUR  
ABERTURA  
DE CHISPA  
1
2
3
4
5
7
6
8
1
2
3
4
5
7
CONDENSATEURS: MFD/VOLTS  
T2  
J12  
A
B
C
D
E
F
4
1
2
3
6
5
CONNECTOR PIN NUMBERS: NOMBRE DE CONTACTS CONNECTEURS  
NÚMEROS DE PINES DE CONECTORES:  
L8  
236  
284  
285  
J23  
J22  
LEAD COLORING CODE:  
233A  
J5  
EXAMPLE: THIS IS PIN 1  
CODE DE COULEUR DES CÂBLES:  
10K A-B  
MINIMUM  
1 2 3  
7
L3  
N.A.  
F
0F CONNECTOR J5  
CÓDIGO DE COLORES DE CABLES:  
EXEMPLE: C'EST LE CONTACT 1  
DU CONNECTEUR J5  
1 2 3  
8
W-WHITE  
BLANC  
6
R-RED  
B-BLACK  
FRONT  
WORK  
PIÈCE  
ROUGE  
14  
8
8
NOIR  
J5  
REMOTE RECEPTACLE  
PRISE À DISTANCE  
ELECTRODE  
EJEMPLO: ESTE ES EL PIN 1 DEL  
CONECTOR J5  
BLANCO  
ROJO  
B-BLUE  
BLEU  
VIEW OF CONNECTOR ON PC BOARD  
VUE DES CONNECTEURS SUR CI  
NEGRO  
R5  
TM  
ÉLECTRODE AVANT  
C7  
Y-YELLOW  
G-GREEN  
VERT  
AMPTROL  
TRABAJO  
RECEPTÁCULO REMOTO  
REAR  
JAUNE  
ARC STARTER AS'BLY  
ENSEMBLE DÉMARREUR D'ARC  
ENSAMBLE DE ARRANCADOR DE  
ARCO  
ELECTRODO FRONTAL  
VISTA DEL CONECTOR EN LA  
TARJETA ELECTRONICA  
AMARILLO  
ELECTRODE  
AZUL  
VERDE  
ELECTRICAL SYMBOLS PER E1537.  
236B  
O-ORANGE  
NARANJA  
ÉLECTRODE ARRIÈRE  
SYMBOLES ÉLECTRIQUES SELON E1537  
A
R
SÍMBOLOS ELÉCTRICOS CONFORME A E1537  
ELECTRODO POSTERIOR  
G5692-1PRINT  
CLEVELAND , OHIO  
NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual. The wiring diagram specific to your code is pasted inside one of the enclosure panels of your machine.  
®
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
G-7  
G-7  
ELECTRICAL DIAGRAMS  
SCHEMATIC - ENTIRE MACHINE - BELOW CODE 11000 (G4075)  
TOROID  
+5V  
TOROID  
SCR1 GATE  
G1  
301  
1J8  
2J8  
3J8  
4J8  
5J8  
6J8  
216  
G4  
G1  
G2  
1J4  
5J4  
2J4  
4J4  
9J4  
6J4  
DECIMAL PT. IN  
IN (+)  
COM  
DECMAL PT.OUT  
IN (-)  
SCR2 GATE  
G2  
302  
SCR3 GATE  
G3  
303  
IN(-)  
306  
SCR4  
SCR1  
304  
304B  
1
2
3
4
5
1
2
3
4
5
6
301  
SCR4 GATE  
G4  
218  
217  
216  
220  
304A  
306  
303  
SCR1,SCR2 CATHODE  
SCR3 CATHODE  
IN(+)  
MAIN  
RECTIFIER  
304B  
302  
220  
METER  
+
-
205mV BETWEEN  
IN(+) & IN(-) IS  
SCR4 CATHODE  
SCR3,SCR4 ANODE  
10J4  
7J4  
220A  
D1  
6
50HZ MACHINE ONLY  
3J4  
X
X
FREE WHEELING DIODE  
205A OR 20.5V  
SCR3  
SCR2  
8J4  
G3  
217  
(VIEWED FROM REAR)  
TOROID  
BYPASS ASSEMBLY  
SHUNT (+)  
1J6  
2J6  
W 221  
R 222  
C4  
218  
SHUNT (-)  
50/60HZ MACHINE ONLY  
MAIN  
TOROID  
TRANSFORMER  
T1 H5  
TOROID  
R 222(-)  
SHUNT  
400A/200mV  
.0047/3KV  
C5  
CW  
+10V  
311  
312  
W 221(+)  
1J9  
2J9  
MICRO SWITCH ON POLARITY SWITCH  
MICRO SWITCH ON POLARITY SWITCH  
6J11  
12J11  
1J11  
MAX  
R1  
265  
266  
252  
253  
PRESET (0 - 10V)  
H4  
POWER SWITCH  
HIGH  
MID  
LOW  
OUTPUT  
10K  
VOLT FEEDBACK, ELECTRODE  
VOLT FEEDBACK, WORK  
H3  
+1.5V  
PT375 ONLY  
L1  
4J9  
10J9  
314  
320  
MIN OUTPUT (0 - 1.5V)  
9J11  
OUTPUT  
H2  
H1  
X1  
223  
L1  
L2A  
CW  
BALANCE (0 - 10V)  
INDUCTOR  
12J9  
6J9  
7J9  
8J9  
11J9  
322  
316  
317  
318  
321  
STICK OCV BOOST CIRCUIT,  
PRESENT ONLY ON PRECISION TIG 375  
BYPASS PCB  
SCHE. S24206-X  
RECONNECT  
MIN  
R4  
X13  
+15V  
PANEL  
OUTPUT  
REMOTE (+15V)  
POSTFLOW (0 - 15V)  
L1A  
10K  
X2  
DISPLAY MIN A (+15V)  
DISPLAY VOLT (+15V)  
L2  
313B  
TOROID  
115VAC IN AC STICK  
115VAC IN DC STICK  
224  
+
+
315  
5J9  
DC  
DC  
DC  
311A  
CW  
10K  
AC  
AC  
MICRO SWITCH  
N.O.  
256  
228  
1J12  
5J12  
225  
225A  
STICK (+15V)  
COM  
-
-
DC  
319  
313  
9J9  
3J9  
R2  
BALANCE  
255  
CR3  
H1  
C2  
CR3  
CR2  
OCV BOOST  
RECTIFIER  
CR2  
212  
AC  
+
313C  
AC  
C1  
C3  
265  
-
+
-
DC  
PRECISION TIG 375  
ONLY  
258  
257  
DC  
DC  
DC  
317  
REMOTE  
CLOSED  
IN DC  
8/300  
AC  
N.C.  
316  
DC  
BOOST  
LOCAL  
CR2  
CR3  
POWER FACTOR  
CAPACITORS  
BOOST  
316A  
CW  
10K  
226  
R14  
227A  
266  
(SHOWN IN REMOTE)  
POLARITY  
SWITCH  
S2  
250  
SEE NOTE A  
R3  
POST FLOW  
313A  
231C  
252  
CR3  
253  
PT375: STANDARD, C1=C2=C3=60/460  
313  
231B  
PT275: OPTIONAL, C1=C2=50/460  
C3 NOT PRESENT  
321  
MIN A  
A
316C  
TIG  
315  
VOLT  
STICK  
319  
TOROID  
MODE SWITCH  
DISPLAY SWITCH  
CONTROL PANEL  
BYPASS/STABILIZER  
PCB  
B
BACKGND FILTER CAP., POS  
BACKGND FILTER CAP., NEG  
(SHOWN IN STICK)  
6J10  
1J10  
7J10  
3J11  
11J11  
10J11  
2J11  
331  
271  
BACKGND RESISTOR  
W
R7  
331  
286  
271A  
BACKGND AC OUT (63.5VAC) IN DC TIG  
BACKGND AC IN (63.5VAC)  
(SCHEMATIC S22530)  
20/100  
B
D2  
332  
BACKGND DIODE  
W
2J10  
8J10  
THERMAL  
(YELLOW)  
332  
GAS  
(GREEN)  
STICK  
(RED)  
REMOTE  
(GREEN)  
X5  
63.5V  
X6  
AUTO BALANCE  
(GREEN)  
268  
267  
268  
B
333  
5/50  
R8  
T1  
267  
W
3J10  
333  
DC TIG BACKGROUND  
CIRCUIT  
BACKGND TRIAC  
CURRENT LIMITING RESISTOR  
1J7  
3J7  
2J7  
B
9J10  
4J10  
220A  
334  
220C  
220B  
W
B
B
W
W
B
B
W
W
B
W
269  
334  
PT375 ONLY  
B
10J10  
5J7  
4J7  
6J7  
BACKGND RECTIFIER  
335  
334  
333  
335  
331  
332  
HOLDING RESISTOR  
W
335  
5J10  
R1  
LED LIGHTS  
FREQUENCY  
TOROID  
NOTE A:  
50/100  
LEAD #250 FROM POWER FACTOR CAPACITORS  
CONNECTS ACCORDING TO THE INPUT VOLTAGE  
ON TIME  
DOWN SLOPE  
HI-FREQ INTENSITY  
WORK  
R13  
HIGHVOLTAGE  
TRANSFORMER  
FRONT  
ELECTRODE  
(STICK WELDING)  
401C  
401D  
208/230/460  
3/25  
238  
TOROID  
200/100  
R5  
CW  
10K  
T2  
PRESENT ONLY ON  
PRECISION TIG 375  
CW  
10K  
CW  
10K  
LEAD #250 CONNECTS TO "HIGH" TERMINAL ON  
RECONNECT PANEL, ALONG WITH CORRECT LEAD  
FROM MAIN TRANSFORMER (T1)  
HI-FREQ (115VAC)  
ADVANCED CONTROL  
6J12  
3J12  
236  
235  
233A  
260  
L2  
402  
407  
405  
C6  
GAS (115VAC)  
115VAC IN  
PCB  
237  
(SCHEMATIC G4039-X)  
(OPTIONAL ON PT275)  
236B  
4J12  
2J12  
12.5 OHM TYP.  
C7  
S
12KV  
.0015/  
403  
220/380/415  
TOROID  
402  
406  
FAN (115VAC)  
15/250  
5.5 OHMS  
TYP.  
J2  
14.5 KOHMS  
TYP.  
SPARK  
GAP  
HIGH FREQ.  
TRANSFORMER  
FREQ. (.08 - 15V)  
ON TIME (1-15V)  
LEAD #250 CONNECTS TO THE H5 LEAD OF  
THE MAIN TRANSFORMER (T1)  
2J1  
12.5 OHM TYP.  
L3  
3J1  
5J1  
6J1  
7J1  
403  
F
405  
406  
407  
BACK GROUND  
230/460/575  
408  
DOWNSLOPE  
401A  
T3  
B
LEAD #250 CONNECTS TO THE "MID" TERMINAL  
ON THE RECONNECT PANEL, ALONG WITH CORRECT  
LEAD FROM THE MAIN TRANSFORMER (T1)  
HI-FREQ CIRCUIT  
8J1  
ON  
4-STEP  
2-STEP  
CW  
9J1  
239  
10J1  
PULSE ON (15V)  
+15V  
409  
W
404  
401  
411  
W
4J1  
1J1  
11J1  
OFF  
460/575  
10K  
REAR  
2-STEP (15V)  
PULSE LED  
GAS  
SOLENOID  
(115VAC)  
LEAD #250 CONNECTS TO THE "LOW" TERMINAL  
ON THE RECONNECT PANEL, ALONG WITH CORRECT  
LEAD FROM THE MAIN TRANSFORMER (T1)  
PULSE  
(GREEN)  
410  
233A  
ELECTRODE  
PULSE  
12J1  
TRIGGER  
(SHOWN IN 2-STEP)  
(SHOWN PULSE ON)  
(TIG WELDING)  
SV1  
231A  
235  
HOT START TRIMMER  
ARC FORCE TRIMMER  
J3  
CB1  
115V/15A  
115 V  
RECEPTACLE  
(TOP)  
233A  
ELECTRICAL SYMBOLS PER E1537  
ADVANCED CONTROL PANEL (OPTIONAL ON PT275)  
2J5A  
3J5A  
4J5A  
5J5A  
7J5A  
1J5A  
6J5A  
8J5A  
232  
233  
COOLER RELAY  
X3  
COMPONENT VALUE  
UNITS:  
LEAD COLORING CODE:  
B-BLACK  
(12VDC)  
233B  
1
2
3
4
262  
COOLER  
RECEPTACLE  
(BOTTOM)  
PRECISION  
TIG 375 ONLY  
G-GREEN  
O-ORANGE  
R-RED  
231F  
260A  
MOVE THIS PLUG FROM  
J5 TO J5A FOR ROBOTIC INTERFACE  
115VAC  
X4  
CAPACITORS:  
MFD/VOLTS  
CR4  
REMOTE  
RECEPTACLE  
BOTTOM FAN  
(115VAC)  
TOP FAN  
(115VAC)  
T1  
231  
FAN  
FAN  
234  
U-BLUE  
W-WHITE  
Y-YELLOW  
WHEN ADVANCED CONTROL  
PCB IS NOT INSTALLED  
263  
RESISTORS:  
OHMS/WATTS  
TOROID  
COOLER, +12VDC IN TIG WELDING  
260  
U
N
A
B
C
D
E
F
4J22  
C9  
C8  
.22/400V  
262  
263  
DISCONNECT FOR  
DOUBLE PRE/POST FLOW  
105VAC  
X14  
5J11  
PLUGGED TO  
COOLER RECEPTACLE  
MAX  
A
2J5  
3J5  
2J23  
10K  
.22/400V  
1J22  
2J22  
3J22  
6J22  
CB2  
COOLER, COMMON  
13J11  
WIPER  
MIN  
B
C
3J23  
4J23  
PRECISION TIG 275 ONLY  
214  
CONNECTOR PIN NUMBERS:  
EXAMPLE: THIS PIN IN  
CONNECTOR J11 IS "6J11"  
R
B
220V 2A  
RECEPTACLE  
4J5  
5J5  
7J5  
TSTAT  
TSTAT  
220V/5A  
212  
215  
14J11  
4J11  
8J11  
5J23  
7J23  
D
E
1 2 3  
8
W
OPTIONAL  
209  
213  
X7  
WATER  
SOLENOID  
KIT  
SV2  
20VAC  
CONTROL BOARD SUPPLY  
210  
50/60HZ MACHINES ONLY  
F
1J5  
6J5  
1J23  
5J22  
16J11  
7J11  
X8  
X9  
(115VAC)  
9
16  
T1  
TOROID  
SECONDARY TSTAT  
PROTECTION  
PRIMARY TSTAT  
TOROID  
201  
LATCH  
8J5  
20VAC  
TM  
(OF MAIN TRANSFORMER T1)  
PCB  
TRIGGER CIRCUIT  
PRECISION TIG 375  
ONLY  
VIEW OF CONNECTOR ON PC BOARD  
OPTIONAL AMPTROL REMOTE  
CONTROL AND ARC START SWITCH  
X10  
15J11  
204  
(SCHEMATIC M16115)  
CONTROL PCB  
AUX. WINDINGS OF  
MAIN TRANSFORMER T1  
( SCHEMATIC G3908-X)  
THIS DOCUMENT CONTAINS PROPRIETARY INFORMATION OWNED BY LINCOLN GLOBAL, INC. AND MAY NOT BE DUPLICATED, COMMUNICATED  
TO OTHER PARTIES OR USED FOR ANY PURPOSE WITHOUT THE EXPRESS WRITTEN PERMISSION OF LINCOLN GLOBAL, INC.  
PROPRIETARY & CONFIDENTIAL:  
UNLESS OTHERWISE SPECIFIED TOLERANCE  
DESIGN INFORMATION  
DRAWN BY: TN  
ENGINEER: TN  
APPROVED:  
REFERENCE:  
MANUFACTURING TOLERANCE PER E2056  
"X" INFO  
XB-UF  
Chg. Sheet No.  
3-8-2002A  
EQUIPMENT TYPE:  
SUBJECT:  
PRECISION TIG  
MACHINE SCHEMATIC  
ON 2 PLACE DECIMALS IS .02  
ON 3 PLACE DECIMALS IS .002  
ON ALL ANGLES IS .5 OF A DEGREE  
SUPERSEDING:  
MATERIAL TOLERANCE (" ") TO AGREE  
t
WITH PUBLISHED STANDARDS.  
01-29-02  
SCALE: NONE DATE:  
DRAWING No.:  
4075  
G
DO NOT SCALE THIS DRAWING  
NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual.  
®
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
G-8  
G-8  
ELECTRICAL DIAGRAMS  
SCHEMATIC - ENTIRE MACHINE - ABOVE CODE 11000 (G5691)  
9 1 5 6 G  
RELEASED FROM X A.02  
CHANGE DETAIL:  
ENGINEERING CONTROLLED  
MANUFACTURER: No  
TOROID  
TOROID  
menu options( jumper IN)  
no menu options ( jumper out)  
SCR1 GATE  
1J13  
2J13  
3J13  
4J13  
5J13  
6J13  
7J13  
8J13  
216  
G4  
G1  
G2  
G1  
1J4  
Push & hold  
at power up = defaults  
left heat-sink  
SCR4  
right heat-sink  
SCR2 GATE  
SCR3 GATE  
G2  
5J4  
GND  
343  
G3  
G4  
218  
217  
216  
220  
2J4  
4J4  
9J4  
6J4  
10J4  
7J4  
Data  
SCR1  
S3  
344  
1
2
3
4
344  
347  
345  
343  
SCR4 GATE  
Clock  
345  
MAIN  
MENU  
SWITCH  
SCR drive  
ckts  
&
METER  
J7  
SCR1,SCR2 CATHODE  
SCR3 CATHODE  
Menu Switch  
346  
BOARD  
+5  
RECTIFIER  
220  
347  
Meter shows  
+
-
very top of welder  
SCR4 CATHODE  
SCR3,SCR4 ANODE  
preset & actual  
Free Wheeling diode  
D1  
316D  
snubbers  
50HZ MACHINE ONLY  
50/60HZ MACHINE  
Caliberation: see new control bd. instructions  
3J4  
8J4  
X
X
SCR3  
SCR2  
G3  
217  
J8 (6pin)  
not used  
346  
ONLY  
TOROID  
Menu Switch hold to get to TIG options  
BYPASS ASSEMBLY  
C4  
SHUNT (+)  
1J6  
2J6  
W 221  
R 222  
lift TIG, upslope  
MAIN  
218  
Menu Switch hold to get to Stickoptions  
amp  
SHUNT (-)  
in reconnect area  
tig hot start levels, micro start  
pre flow/after flow time extended  
see IM for details and more  
TRANSFORMER  
center of base mounted on its side  
arc force levels  
hot start levels  
PT375 = 86 vac  
PT275 =75 vac  
to X2  
TOROID  
TOROID  
R 222(-)  
SHUNT  
.0047/3KV  
C5  
CW  
10K  
+10V  
311  
T1 H5  
400A/200mV  
MAX  
OUTPUT  
W 221(+)  
1J9  
2J9  
MICRO SWITCH ON POLARITY SWITCH  
MICRO SWITCH ON POLARITY SWITCH  
6J11  
265  
266  
252  
253  
PRESET (0 - 10V)  
312  
upper left  
R1  
H4  
H3  
H2  
POWER SWITCH  
HIGH  
MID  
LOW  
12J11  
VOLT FEEDBACK, ELECTRODE  
VOLT FEEDBACK, WORK  
IC chip  
controller  
+1.5V  
314  
1J11  
9J11  
PT375 ONLY  
L1  
L2  
4J9  
10J9  
scaling  
MIN OUTPUT (0 - 1.5V)  
320  
OUTPUT  
X1  
L1  
L2A  
223  
CW  
BALANCE (0 - 10V)  
INDUCTOR  
12J9  
6J9  
7J9  
8J9  
11J9  
322  
AC & DC STICK OCV BOOST CIRCUIT,  
PRESENT ONLY ON PRECISION TIG 375  
BYPASS PCB  
SCHE. S24206-X  
RECONNECT  
PANEL  
middle section  
MIN  
R4  
X13  
+15V  
316  
75vac  
(375 only)  
OUTPUT  
REMOTE (+15V)  
317  
L1A  
right front lower  
10K  
POSTFLOW (0 - 15V)  
318  
H1  
X2  
DISPLAY MIN A (+15V)  
313B  
321  
TOROID  
115VAC IN  
224  
DISPLAY VOLT (+15V)  
315  
+
+
5J9  
DC  
DC  
AC STICK  
311A  
CW  
10K  
AC  
AC  
MICRO SWITCH  
near power switch  
256  
1J12  
5J12  
225A  
228  
225  
STICK (+15V)  
-
-
DC  
319  
COM  
313  
DC  
9J9  
3J9  
R2  
N.O.  
BALANCE  
313C  
255  
CR3  
H1  
C2  
115VAC IN  
DC STICK  
CR3  
CR2  
CR2  
Sets weld tables  
212  
IC chip  
controller  
& CR2 ,CR3 control  
265  
opto  
triac  
AC  
either is ref  
to 231A  
OCV BOOST  
RECTIFIER  
AC  
C1  
C3  
-
+
-
DC  
+
DC  
PRECISION TIG 375  
ONLY  
258  
257  
DC  
DC  
317  
316  
REMOTE  
opto  
triac  
CLOSED  
IN DC  
in reconnect area  
POWER FACTOR  
CAPACITORS  
N.C.  
8/300W  
AC  
DC  
BOOST  
115VAC  
LOCAL  
CR2  
CR3  
BOOST  
316A  
226  
CW  
R14  
227A  
266  
115VAC  
(SHOWN IN REMOTE)  
POLARITY  
SWITCH  
250  
SEE NOTE A  
R3  
220B  
POST FLOW  
231C  
252  
10K  
313  
CR3  
253  
S2  
front  
large cap and  
resistor filter  
PT375: STANDARD, C1=C2=C3=60/460V  
115V common  
313A  
231B  
PT275: OPTIONAL, C1=C2=50/460V  
C3 NOT PRESENT  
321  
BACKGROUND CIRCUIT  
ENABLED IN BOTH TIG  
& STICK, AC & DC  
MIN A  
A
375 ONLY  
275 ONLY  
current limiting resistors  
to main rectifier  
316C  
TIG  
R
275 = 5/50W 4 ea  
left front lower  
315  
VOLT  
STICK  
375 = 25/25W 4 ea  
319  
TOROID  
upper section near lift bale  
BACKGND FILTER CAP., POS  
BACKGND FILTER CAP., NEG  
MODE SWITCH  
3J11  
11J11  
271  
229A  
DISPLAY SWITCH  
CONTROL PANEL  
BYPASS/STABILIZER  
B
(SHOWN IN STICK)  
6J10  
1J10  
7J10  
331  
stick  
PCB  
271A  
W
bottom right in RF section  
331  
(SCHEMATIC S22530)  
10J11  
2J11  
375 ONLY  
BACKGND AC OUT  
BACKGND AC IN  
B
332  
opto  
triac  
BACKGND  
RESISTORS  
auto  
W
2J10  
8J10  
THERMAL  
(YELLOW)  
332  
333  
GAS  
(GREEN)  
STICK  
(RED)  
REMOTE  
(GREEN)  
X5  
AUTO BALANCE  
(GREEN)  
269  
B
OCV clamp  
T1  
63.5V  
remote  
BACKGND  
RECTIFIER  
W
B
3J10  
333  
334  
X6  
1J7  
3J7  
2J7  
9J10  
4J10  
229  
W
B
B
W
W
B
B
W
W
gas  
B
opto  
triac  
W
B
334  
335  
PT375 use ONLY  
10J10  
5J7  
4J7  
6J7  
334  
333  
335  
331  
332  
opto  
triac  
min current range:  
375=2 to 65A  
275=2 to 55A  
HOLDING RESISTOR  
thermo  
W
335  
5J10  
R1  
opto  
triac  
LED LIGHTS  
FREQUENCY  
CW  
TOROID  
50/100W  
base front  
max current range:  
375=340A  
275=420A  
HI-FREQ INTENSITY  
(bottom right side)  
ON TIME  
CW  
DOWN SLOPE  
CW  
(bottom behind fan)  
WORK  
(right front)  
R13  
3/25W  
HIGHVOLTAGE  
TRANSFORMER  
FRONT  
ELECTRODE  
(STICK WELDING)  
401C  
401D  
PRESENT ONLY ON  
PRECISION TIG 375  
board mounted parts  
(right side in box)  
TOROID  
200/100W  
R5  
T2  
238  
HI-FREQ (115VAC)  
GAS (115VAC)  
115VAC IN  
ADVANCED CONTROL  
6J12  
3J12  
236  
235  
233A  
260  
L2  
402  
407  
405  
C6  
PCB  
237  
NOTE A:  
10K  
min  
10K  
min  
10K  
min  
(SCHEMATIC G4760-X)  
(OPTIONAL ON PT275)  
236B  
4J12  
2J12  
12.5 OHM TYP.  
LEAD #250 FROM POWER FACTOR CAPACITORS  
CONNECTS ACCORDING TO THE INPUT VOLTAGE  
C7  
S
12KV  
.0015/  
403  
TOROID  
402  
15/250V  
406  
FAN (115VAC)  
5.5 OHMS  
TYP.  
14.5 KOHMS  
J2  
SPARK  
GAP  
.015"  
FREQ. (.08 - 15V)  
ON TIME (1-15V)  
HIGH FREQ.  
TRANSFORMER  
2J1  
3J1  
5J1  
6J1  
7J1  
TYP.  
12.5 OHM TYP.  
L3  
115V common  
208/230/460  
10 pin molex  
403  
SPOT  
SPOT  
(RED)  
F
B
405  
406  
407  
BACK GROUND  
LEAD #250 CONNECTS TO "HIGH" TERMINAL ON  
RECONNECT PANEL, ALONG WITH CORRECT LEAD  
FROM MAIN TRANSFORMER (T1)  
408  
W
DOWNSLOPE  
401A  
T3  
5KV  
B
HI-FREQ CIRCUIT  
8J1  
Dip Switches select:  
a. re-start enable  
b.ramp down to zero  
c. see IM for details  
and more.  
OFF  
4-STEP  
2-STEP  
CW  
9J1  
239  
115V common  
10J1  
220/380/415  
PULSE ON (15V)  
+15V  
409  
W
404  
401  
411  
W
(right side)  
4J1  
1J1  
11J1  
LEAD #250 CONNECTS TO THE H5 LEAD OF  
THE MAIN TRANSFORMER (T1)  
10K  
REAR  
2-STEP (15V)  
PULSE LED  
GAS  
SOLENOID  
(115VAC)  
PULSE  
PULSE  
d.most old options  
on menu feature now.  
410  
233A  
ELECTRODE  
12J1  
TRIGGER  
inside side box right  
(GREEN) flashes with  
(SHOWN IN 2-STEP)  
230/460/575  
(TIG WELDING)  
+15 LED  
+5 LED  
115V common  
pulse frequency  
SV1  
231A  
235  
413  
W
1J20  
2J20  
LEAD #250 CONNECTS TO THE "MID" TERMINAL  
ON THE RECONNECT PANEL, ALONG WITH CORRECT  
LEAD FROM THE MAIN TRANSFORMER (T1)  
CB1  
115V/15A  
115 V  
RECEPTACLE  
(TOP of plug)  
"ON" with input power sw.  
233A  
HOT START TRIMMER  
ARC FORCE TRIMMER  
J3  
Fans "ON" @  
15A in stick mode  
2A in tig mode  
"ON" 8 minutes after  
weld stops  
not used:see  
menu options  
ADVANCED CONTROL PANEL (OPTIONAL ON PT275)  
outside of right side box  
COOLER RELAY  
(12VDC)  
2J5A  
3J5A  
4J5A  
5J5A  
7J5A  
1J5A  
6J5A  
8J5A  
232  
233  
460/575  
X3  
233B  
1
2
3
4
262  
LEAD #250 CONNECTS TO THE "LOW" TERMINAL  
ON THE RECONNECT PANEL, ALONG WITH CORRECT  
LEAD FROM THE MAIN TRANSFORMER (T1)  
COOLER  
PRECISION  
TIG 375 ONLY  
10 pin molex  
231F  
MOVE THIS PLUG FROM  
J5 TO J5A FOR ROBOTIC INTERFACE  
115VAC  
X4  
RECEPTACLE  
(BOTTOM of plug)  
"ON" with output  
231  
CR4  
REMOTE  
RECEPTACLE  
TOP FAN  
(115VAC)  
BOTTOM FAN  
T1  
(115VAC)  
FAN  
FAN  
234  
c.c. w  
WHEN ADVANCED CONTROL  
PCB IS NOT INSTALLED  
c.w.  
263  
TOROID  
intake  
exhaust  
260  
ELECTRICAL SYMBOLS PER E1537  
U
N
A
B
C
D
E
F
4J22  
C9  
C8  
.22/400V  
COOLER, +12VDC IN TIG WELDING  
COOLER, COMMON  
260A  
212  
262  
263  
DISCONNECT FOR  
5J11  
105VAC  
X14  
PLUGGED TO  
COOLER RECEPTACLE  
MAX  
.22/400V  
A
2J5  
3J5  
DOUBLE PRE/POST FLOW  
(top rear)  
2J23  
10K  
1J22  
2J22  
3J22  
6J22  
CB2  
COMPONENT VALUE UNITS:  
LEAD COLOR CODE:  
13J11  
com  
WIPER  
MIN  
B
C
3J23  
4J23  
PRECISION TIG 275 ONLY  
214  
Make sure that the rear EXTERNAL  
baffle is inplace and not damaged.  
B-BLACK OR GRAY  
G-GREEN  
O-ORANGE  
R-RED OR PINK  
U-BLUE  
CAPACITOR: MFD/VOLTS  
RESISTOR: OHMS/WATTS  
R
B
To & From  
driver  
220V 2A  
RECEPTACLE  
IC chip  
4J5  
5J5  
7J5  
TSTAT  
TSTAT  
220V/5A  
14J11  
4J11  
8J11  
+8  
5J23  
7J23  
D
E
com +12  
opto  
CONNECTOR PIN NUMBERS:  
EX. 12 PIN CONNECTOR  
W
OPTIONAL  
209  
X7  
213  
215  
lead  
mounted  
WATER  
SOLENOID  
KIT  
W-WHITE  
SV2  
20VAC  
50/60HZ MACHINES ONLY  
F
1J5  
6J5  
1J23  
Y-YELLOW  
5J22  
CONTROL BOARD SUPPLY  
N.C.  
N.C.  
wounded into  
primary  
PRIMARY TSTAT  
2
1
6
16J11  
7J11  
X8  
X9  
(115VAC)  
210  
LABELS:  
T1  
TOROID  
to thermo  
led & CPU  
SECONDARY TSTAT  
PROTECTION  
TOROID  
201  
8J5  
20VAC  
COMMON  
TM  
(OF MAIN TRANSFORMER T1)  
turns off SCR's  
PCB  
TRIGGER CIRCUIT  
204  
PRECISION TIG 375  
ONLY  
OPTIONAL AMPTROL REMOTE  
CONTROL AND ARC START SWITCH  
7
12  
X10  
15J11  
(SCHEMATIC M16115)  
TOP FAN  
FRAME GROUND  
EARTH GROUND  
LATCH  
K870 foot pedal jumper  
to enable Pot (R1) max output  
limiter fearure. Jumper not used  
in Robotic molex position J5A  
CONTROL PCB  
AUX. WINDINGS OF  
MAIN TRANSFORMER T1  
VIEW OF CONNECTOR ON PC BOARD  
( SCHEMATIC G4762-X)  
THIS DOCUMENT CONTAINS PROPRIETARY INFORMATION OWNED BY LINCOLN GLOBAL, INC. AND MAY NOT BE DUPLICATED, COMMUNICATED  
TO OTHER PARTIES OR USED FOR ANY PURPOSE WITHOUT THE EXPRESS WRITTEN PERMISSION OF LINCOLN GLOBAL, INC.  
PROPRIETARY & CONFIDENTIAL:  
SCALE:  
DESIGN INFORMATION  
EQUIPMENT TYPE:  
SUBJECT:  
1
1
THE INFORMATION ON THIS  
PRECISION TIG  
PAGE ___ OF ___  
NONE  
PRINT IS FOR REFERENCE  
ONLY. COMPONENTS AND  
CIRCUITRY MAY BE DIFFERENT  
FROM AN ACTUAL MACHINE.  
bburkhart  
DRAWN BY:  
DOCUMENT  
DOCUMENT  
NUMBER:  
IF PRINTED  
@ A1 SIZE  
MACHINE SCHEMATIC  
REVISION:  
ENGINEER: burkhart  
APPROVED:  
UNITS:  
REFERENCE:  
G4075  
MATERIAL  
PROJECT  
NUMBER:  
APPROVA7L-27-2007  
G5691  
A
NA  
CRM38261  
-
NONE DISPOSITION:  
DATE:  
NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual.  
®
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
G-9  
G-9  
ELECTRICAL DIAGRAMS  
SCHEMATIC - CONTROL PC BOARD - BELOW CODE 11000 (G3908 PAGE 1)  
NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual.  
®
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
G-10  
G-10  
ELECTRICAL DIAGRAMS  
SCHEMATIC - CONTROL PC BOARD - BELOW CODE 11000 (G3908 PAGE 2)  
NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual.  
®
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
G-11  
G-11  
ELECTRICAL DIAGRAMS  
SCHEMATIC - CONTROL PC BOARD - BELOW CODE 11000 (G3908 PAGE 3)  
NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual.  
®
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
G-12  
G-12  
ELECTRICAL DIAGRAMS  
PC BOARD ASSEMBLY-CONTROL - BELOW CODE 11000 (G3909-2)  
2 9 - 9 0 3 G  
ITEM  
REQ'D PART NO.  
DESCRIPTION  
CHANGE DETAIL: ADDED C178 AND REVISED DZ14 PART NUMBER  
ENGINEERING CONTROLLED  
MANUFACTURER: No  
R20, R40, R41, R44,  
R55, R60, R75, R76,  
R80, R90, R107, R136,  
R176, R210, R213,  
R214, R241, R275,  
R282, R283, R287,  
R288, R291, R319,  
R323, R324, R325,  
R329, R330, R331,  
R355, R359, R361  
R23, R62, R63, R78,  
R92, R103, R104,  
R105, R129, R140,  
R161, R179, R202,  
R206, R207, R208,  
R239, R243, R257,  
R263, R267, R273,  
R274, R279, R305,  
R312, R314, R315,  
R320, R364  
REVISEDMANUFACTUREAS, IDENTIFCI ATOI N CODE AND SCHEMATCI REFERENCE PART NUMBERS  
REFER TO ELECTRONIC COMPONENT DATABASE FOR SPECIFICATIONS ON ITEMS LISTED BELOW  
REFERENCES QTY PART NUMBER DESCRIPTION  
ADDED SOLDER AND SEALANT NOTE FOR C178 TOASSEMBLY  
C1, C7, C178  
3
S16668-8  
CAPACITOR,CEMO,330pF,100V,5%  
C2, C3, C5, C17, C21,  
C25, C28, C33, C36,  
C41, C46, C48, C50,  
C54, C55, C57, C61,  
C69, C70, C71, C76,  
C77, C78, C85, C86,  
C89, C90, C94, C103,  
C105, C106, C109,  
C111, C122, C123,  
C124, C125, C126,  
C129, C130, C139,  
C148, C149, C157,  
C158, C165  
33  
S19400-4751  
RESISTOR,MF,1/4W,4.75K,1%  
46  
S16668-11  
CAPACITOR,CEMO,0.1, 50V,10%  
30  
S19400-1001  
RESISTOR,MF,1/4W,1.00K,1%  
C4, C8, C9, C11, C12,  
C26, C27, C29, C32,  
C42, C43, C44, C47,  
C56, C65, C66, C67,  
C68, C83, C87, C92,  
C101  
22  
S16668-6  
CAPACITOR,CEMO,4700pF,50V,10%  
R27, R43  
R28  
2
1
4
S19400-2213  
S19400-3921  
S19400-1372  
RESISTOR,MF,1/4W,221K,1%  
RESISTOR,MF,1/4W,3.92K,1%  
RESISTOR,MF,1/4W,13.7K,1%  
C6, C16, C20, C35,  
C59, C63, C100, C118,  
C143, C155  
10  
3
S13490-42  
S16668-3  
CAPACITOR,TAEL,1.0,35V,10%  
R30, R35, R36, R66  
R37, R335, R342,  
R344, R345, R347  
R39, R79  
R42, R128, R164,  
R169, R215, R216,  
R245, R260, R261,  
R339  
C10, C24, C58  
CAPACITOR,CEMO,100pF, 100V,5%  
6
2
S19400-2000  
S19400-3011  
RESISTOR,MF,1/4W,200,1%  
RESISTOR,MF,1/4W,3.01K,1%  
C13, C18, C19, C30,  
C31, C34, C37, C38,  
C40, C45, C62, C64,  
C72, C73, C74, C75,  
C79, C80, C88, C91,  
C104, C107, C112,  
C128, C134, C142,  
C144, C145, C146,  
C147, C150, C151,  
C152, C153, C154,  
C156, C159  
10  
S19400-4752  
RESISTOR,MF,1/4W,47.5K ,1%  
37  
S16668-5  
CAPACITOR,CEMO,.022,50V,20%  
R45, R85, R86, R108,  
R171  
5
2
4
S19400-2002  
S19400-2210  
S19400-3321  
RESISTOR,MF,1/4W,20.0K,1%  
RESISTOR,MF,1/4W,221,1%  
RESISTOR,MF,1/4W,3.32K,1%  
R57, R69  
1
R59, R173, R252, R259  
C14, C127  
C15, C141, C164  
C22, C51  
C23, C39, C52  
C49, C60  
2
3
2
3
2
1
S13490-25  
S13490-181  
T11577-54  
S13490-183  
S16668-7  
CAPACITOR,TAEL,4.7,35V 10%  
CAPACITOR,ALEL,22,63V,20%  
CAPACITOR,CD,750PF,1000V,10%  
CAPACITOR,ALEL,120MF,50V,20%  
CAPACITOR,CEMO,820pF,50V,5%  
CAPACITOR,ALEL,3300, 50V,+30/-10%  
SOLDERCAPACITOR(C178) TOR108AS SHOWN.  
COVERWITHE2861SEALANT.  
N.B.  
3
R64, R65, R73, R74,  
R93, R94, R114, R131,  
R135, R170, R205,  
R258, R270, R292,  
R295  
R71, R83, R87, R118,  
R168, R248, R249,  
R256, R277, R280  
1.20  
N.D.  
15  
S19400-1003  
RESISTOR,MF,1/4W,100K,1%  
N.D.  
N.D.  
N.F.  
16.80  
C53  
S13490-92  
10.68  
C81, C82, C98, C99,  
C117, C131, C133,  
C135, C136, C137,  
C140, C160, C161,  
C162, C163  
15  
T11577-58K  
CAPACITOR,CD,.0047,3000V,20%  
10  
4
S19400-1004  
S19400-26R7  
RESISTOR,MF,1/4W,1.00M,1%  
RESISTOR,MF,1/4W,26.7,1%  
6.00  
5.80  
R72, R101, R102, R276  
R8  
C3  
C84  
C93, C108  
C95, C96, C97  
C102, C138  
1
2
3
2
1
S13490-40  
S16668-1  
T11577-46K  
S16668-9  
S16668-4  
CAPACITOR,TAEL,2.7,50V,10%  
DZ1  
R10  
D1  
R9  
C2  
R27  
C5  
R12  
R33  
C4  
Q9  
D2  
C6  
CAPACITOR,CEMO,22pF, 100V,5%  
CAPACITOR,CD,.05,600V,+80/-20%  
CAPACITOR,CEMO,150pF, 100V,5%  
CAPACITOR,CEMO, 2700pF, 50V,5%  
C1  
R13  
R77, R110, R111  
R81, R313  
R82, R316, R357  
R100, R271, R334,  
R337, R340, R341  
R112  
3
2
3
S19400-2001  
S19400-9091  
S19400-3012  
RESISTOR,MF,1/4W,2.00K,1%  
RESISTOR,MF,1/4W,9.09K,1%  
RESISTOR,MF,1/4W,30.1K,1%  
R24  
DZ24  
DZ3  
R16  
D10  
R2  
D12  
C21  
D13  
R43  
R28  
R11  
R23  
D3  
C23  
Q7  
R29  
C13  
X3  
R40  
R41  
C7  
R17  
C10  
C18  
C19  
C22  
R30  
R31  
R32  
R66  
R14  
C8  
R18  
R20  
R34  
R35  
R36  
R68  
R69  
R70  
R71  
C110  
D6  
C20  
R44  
R45  
R83  
R84  
R85  
R86  
R87  
R108  
Q8  
C9  
C11  
XXX  
R21  
D4  
R73  
C15  
C113, C114, C115,  
C116  
D11  
D22  
R42  
R79  
R15  
R47  
R48  
R49  
R19  
R25  
D7  
C14  
4
S13490-81  
CAPACITOR,PEF,0.1MF,400V,10%,RADIAL  
6
S19400-5110  
RESISTOR,MF,1/4W,511,1%  
R22  
R77  
R78  
XXX  
D18  
C26  
Q12  
Q14  
R60  
R74  
R51  
R55  
R62  
R63  
D26  
C38  
R58  
R59  
C27  
C34  
C35  
D27  
C40  
D19  
DZ4  
R107  
R80  
C119, C120  
C121  
C132  
2
1
1
S16668-2  
S13490-19  
S13490-186  
CAPACITOR,CEMO,47pF, 100V,5%  
CAPACITOR,TAEL,1.8,20V,10%  
CAPACITOR,ALEL,1800,160V,20%  
R52  
DZ25  
1
1
S19400-9092  
S19400-2211  
RESISTOR,MF,1/4W,90.9K,1%  
RESISTOR,MF,1/4W,2.21K,1%  
Q10  
Q11  
C24  
R56  
DZ22  
D23  
R53  
R54  
D17  
C31  
R64  
R65  
R67  
C32  
R72  
D21  
R61  
R75  
R76  
R113  
R81  
R50  
D16  
D20  
C28  
C44  
C29  
C30  
Q15  
Q13  
R82  
C53  
R121, R124, R244,  
R318  
R137, R138, R181,  
R217, R262, R304  
R139, R180, R218,  
R264  
C25  
D24  
Q16  
C52  
R88  
D1, D4, D7, D16, D17,  
D18, D20, D21, D23,  
D28, D34, D36, D37,  
D38, D39, D90  
4
6
4
S19400-7681  
S19400-1211  
S19400-2670  
RESISTOR,MF,1/4W,7.68K,1%  
RESISTOR,MF,1/4W,1.21K,1%  
RESISTOR,MF,1/4W,267,1%  
X
C48  
D31  
C36  
Q21  
R105  
R106  
C49  
R101  
R102  
C47  
R95  
R96  
D34  
G3909-2  
C41  
R91  
C45  
R93  
R94  
R99  
Q17  
Q18  
C178  
R57  
C43  
R90  
D28  
D29  
C51  
16  
T12705-34  
DIODE,AXLDS,1A,400V,FR,1N4936  
R97  
R98  
R355  
R100  
C50  
DZ5  
X
R359  
PRECISION TIG CONTROL  
R103  
R110  
R111  
N.D.  
R109  
D30  
R120  
C63  
C64  
C46  
R104  
C58  
T1  
T2  
D2, D3, D5, D6, D10,  
D11, D12, D13, D14,  
D15, D19, D22, D25,  
D26, D27, D29, D30,  
D31, D35, D40, D41,  
D42, D51, D54, D55,  
D58, D59, D60, D61,  
D64, D65, D66, D67,  
D72, D73, D79, D80,  
D81, D82, D83, D84,  
D85, D86, D87, D88,  
D89  
R132  
R133  
R130  
R131  
R116  
R117  
D40  
R129  
R3  
R121  
R92  
C55  
R126  
R127  
R112  
D46  
D48  
R113  
OCI1  
R122  
R139  
C60  
C62  
R135  
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
R162, R333, R338  
R165  
3
1
1
S19400-3320  
S19400-3323  
S19400-5621  
RESISTOR,MF,1/4W,332,1%  
RESISTOR,MF,1/4W,332K,1%  
RESISTOR,MF,1/4W,5.62K,1%  
Q20  
D41  
R119  
DZ6  
C56  
R125  
R167  
D42  
X
X
X
X
X
X
X
X
X
X
X
X
X
X
R114  
C54  
R123  
R124  
R163  
R164  
C72  
R134  
R175  
D47  
D49  
C59  
Q19  
D36  
D37  
D38  
D39  
C61  
R361  
DZ21  
D58  
R136  
C77  
R118  
R159  
R140  
C80  
R128  
C74  
R115  
R157  
R166  
C76  
R168  
R169  
C73  
D54  
46  
T12199-1  
DIODE,AXLDS,1A,400V  
R161  
R162  
C70  
R167, R174, R284,  
R285, R301, R326,  
R327  
D51  
R205  
R170  
C75  
R176  
R211  
C92  
C78  
R177  
X X  
C69  
R160  
C81  
7
1
S19400-1501  
T14648-24  
RESISTOR,MF,1/4W,1.50K,1%  
RESISTOR,WW,5W,0.5,5%,SQ  
N.C.  
R203  
R165  
R166  
R173  
R174  
R208  
C91  
C82  
C99  
X
X
X
X
X
X
X
X
X
X
X
X
R158  
C83  
C71  
D62  
R215  
R216  
R260  
R261  
D59  
D61  
C84  
D64  
R358  
C165  
C97  
X
X
X
X
X
X
X
X
D55  
R212  
R178  
D60  
D88  
R204  
C87  
D89  
R202  
D63  
R213  
XXXX  
C96  
C98  
R218  
R182, R183, R184,  
R185, R186, R187,  
R188, R189, R190,  
R191, R192, R193,  
R194, R195, R196,  
R197, R198, R199,  
R200, R201, R219,  
R220, R221, R222,  
R223, R224, R225,  
R226, R227, R228,  
R229, R230, R231,  
R232, R233, R234,  
R235, R236, R237,  
R238  
R209  
R210  
C93  
C89  
C90  
C85  
N.C.  
R214  
C94  
Q23  
Q26  
D24, D62, D63  
D46, D47, D48, D49,  
D50  
3
5
T12705-23  
T12705-14  
DIODE,SCHOTTKY,AXLDS,1A,30V,1N5818  
DIODE,AXLDS,3A,200V,1N5402  
C86  
C88  
D65  
R4  
R357  
C105  
R257  
R258  
R259  
R246  
R247  
X18  
C103  
C104  
C106  
DZ10  
C123  
R252  
R263  
C112  
DZ9  
Q25  
X X  
C109  
C110  
X X  
R248  
R251  
C108  
R291  
R244  
R254  
D68, D69, D70, D71  
DZ1, DZ3, DZ9, DZ14  
DZ2, DZ5, DZ20  
4
4
3
T12199-2  
T12702-29  
T12702-53  
DIODE,AXLDS,1A,1000V  
ZENER DIODE,1W,15V,5%,1N4744A  
ZENER DIODE,1W,3.3V,5%,1N4728A  
C111  
Q27  
R245  
R270  
R271  
R272  
R273  
C119  
R311  
D67  
C102  
R269  
R249  
C107  
C125  
R255  
R253  
X
X
X
R264  
X
X
X
X
OCI6  
R275  
R276  
C120  
R292  
C126  
C127  
C133  
R6  
40  
S19400-68R1  
RESISTOR,MF,1/4W,68.1,1%  
R305  
C134  
R293  
R336  
C151  
X
X
R277  
R278  
R279  
R315  
R316  
R317  
R318  
R321  
X
X
DZ4, DZ11, DZ12, DZ13  
4
2
2
T12702-27  
T12702-19  
T12702-23  
ZENER DIODE,1W,10V,5%,1N4740A  
ZENER DIODE,1W,12V,5%,1N4742A  
ZENER DIODE,5W,15V,5%,1N5352B  
R265  
R266  
XXX  
DZ6, DZ10  
DZ7, DZ8  
DZ15, DZ16, DZ17,  
DZ18, DZ19, DZ21,  
DZ22  
X
X
X
X
R274  
R312  
C144  
R313  
C156  
XXXXXXXXX  
OCI7  
C135  
TP4  
N.C., N.D.  
DZ17  
XXX  
D81  
D82  
TP9  
TP11  
X
X
X
X
X
7
T12702-52  
ZENER DIODE,1W,5.1V,5%,1N4733A  
X
TP7  
XXXX  
XXXX  
R306  
TP10  
TP12  
R351  
C141  
XXXX  
TP5  
TP6  
C143  
R314  
DZ23, DZ24, DZ25  
J2, J3  
J4, J10  
J5, J5A  
J6  
J7, J8, J12  
J9  
J11  
3
2
2
2
1
3
1
1
2
T12702-45  
S21134-10  
S24020-10  
S24020-8  
S24020-2G  
S24020-6  
S24020-12  
S24020-16  
T12218-9  
ZENER DIODE,1W,18V,5%,1N4746A  
R335  
D83  
C158  
D87  
C163  
C157  
CONNECTOR,MOLEX,MINI,BLIND,F,10-PIN  
CONNECTOR,MOLEX,MINI,PCB,10-PIN,TIN  
CONNECTOR,MOLEX,MINI,PCB,8-PIN,TIN  
CONNECTOR,MOLEX,MINI,PCB,2-PIN,GOLD  
CONNECTOR,MOLEX,MINI,PCB,6-PIN,TIN  
CONNECTOR,MOLEX,MINI,PCB,12-PIN,TIN  
CONNECTOR,MOLEX,MINI,PCB,16-PIN,TIN  
CHOKE,RF,390UH,5%, 225MA,CONFORMAL  
X X X X  
J4  
X X X X  
X X  
J6  
C150 X X X X  
X X X X X  
J11  
X
X
4
4
S18380-1  
THERMISTOR,PTC,56 OHMS,90MA  
RESISTOR,MF,1/4W,249,1%  
R265, R266, R306,  
R351  
R268, R309, R343,  
R346  
N.D.  
R7  
R352  
R353  
X
X
X
J8  
X X X X  
J9  
X X X X  
J5  
X
X
X
C159  
N.F.  
J5A  
J7  
J10  
J12  
S19400-2490  
X X X X X X  
X X X X X  
X X X X  
X
X X X X X X X  
X X  
X X X  
X
X X X X X X  
X X X X X X  
R269, R307  
2
1
2
1
1
1
S19400-2673  
S19400-3922  
S19400-2802  
S18380-3  
S19400-6810  
S19400-3570  
RESISTOR,MF,1/4W,267K,1%  
RESISTOR,MF,1/4W,39.2K,1%  
RESISTOR,MF,1/4W,28.0K,1%  
THERMISTOR,PTC,.08-0.19 OHMS,1.85A  
RESISTOR,MF,1/4W,681,1%  
.20  
0
R272  
L1, L2  
R286, R328  
OCI1, OCI2, OCI5, OCI8  
4
S15000-16  
OPTOCOUPLER,TRIAC,DRIVER,ZVC,3083  
R303  
R310  
R322  
N.C., N.D.  
OCI3, OCI4  
OCI6, OCI7  
Q1, Q4, Q18  
2
2
3
S15000-31  
S15000-10  
T12704-69  
OPTOCOUPLER,TRIAC,DRV,RANDOM,800V  
OPTOCOUPLER,PHOTO-Q,70V,CNY17-3  
TRANSISTOR,PNP,TO226,0.5A, 40V,2N4403  
N.F.  
N.C., N.D.  
N.C., N.D.  
RESISTOR,MF,1/4W,357,1%  
N.D.  
N.D.  
N.F.  
17.80  
18.00  
N.D.  
R348, R349, R362,  
R363  
.20  
4
S19400-20R0  
RESISTOR,MF,1/4W,20.0,1%  
N.C.  
Q2, Q3, Q5, Q6, Q7,  
Q8, Q9, Q12, Q13,  
Q14, Q15, Q16, Q17,  
Q19, Q20, Q21, Q22,  
Q23, Q24, Q26, Q27,  
Q28  
N.E.  
0
6.00  
12.00  
2
4
1
T12737-2  
T13640-25  
T13640-16  
T1, T2  
TRANSFORMER,PULSE,3-WINDING,1:1:1  
MOV,130VRMS,90J,20MM  
MOV,150VRMS,80J,20MM  
TP1, TP3, TP5, TP6  
22  
T12704-68  
TRANSISTOR,NPN,TO226,0.5A,40V,2N4401  
TP2  
TP4, TP7, TP9, TP10,  
TP11, TP12  
6
T13640-18  
MOV,320VRMS,150J,20MM  
Q10, Q11  
Q25  
R1, R3, R5  
R2  
R4, R7  
R6  
2
1
3
1
2
1
T12704-54  
T12704-73  
S16296-3  
T10812-41  
T10812-73  
S16296-5  
TRANSISTOR,NMF,TO220,15A,60V,(SS)  
TRANSISTOR,NMF,4-PIN DIP,1A,100V,IRFD110(SS)  
TRIMMER,MT,1/2W,500, 10%,LINEAR  
TRIMMER,ST,1/2W,10K, 10%,LINEAR  
TRIMMER,ST,1/2W,2K, 10%,LINEAR  
N.A.  
N.A.  
1
2
2
1
2
1
3
1
2
4
1
1
1
1
1
1
T13640-14  
S18395-27  
S15161-27  
S15018-15  
S15018-4  
S15128-10  
S15018-6  
S18395-8  
S18395-3  
S15128-4  
S15128-18  
S25431-2  
M15102-4  
M15102-3  
S15128-16  
S16665-2  
TP8  
MOV,150VRMS,13J,7MM  
TRIAC,T220,8A,800V WITH S18104-3HS  
TRIAC,T220,8A,800V  
TRI1, TRI2  
TRI3, TRI4  
ITEM  
PART NO.  
DESCRIPTOI N  
REQD  
X1  
X2, X11  
X3  
IC,CMOS,GATE,NAND,2-INPUT,QUAD,SCHM(SS)  
IC,CMOS,INVERTER,SCHMITT, HEX,4584(SS)  
VOLTAGE REF,ADJ, PRECISION,431I  
IC,CMOS,SWITCH,ANALOG,QUAD, 4066(SS)  
REGULATOR,HEAT-SINKASBLY,S15128-6,S18104-3  
REGULATOR,HEAT-SINKASBLY,S15128-5,S18104-3  
OP-AMP,QUAD, GEN-PURPOSE,224N  
OP-AMP,QUAD, HIGH-PERF,33074  
N.A.  
N.A.  
TRIMMER,MT,1/2W,10K, 10%,LINEAR  
1
2
3
1
SEEBLANK INFO.  
E2861  
S19300-7  
P.C.BOARDBLANK REF.  
SEALANT  
PCB SUPPORT  
R8, R16, R120, R122,  
R172, R317, R356  
R9, R91, R116, R117,  
R350  
R10, R98, R177, R278,  
R336  
7
5
5
S19400-1000  
S19400-3322  
S19400-4750  
RESISTOR,MF,1/4W,100,1%  
RESISTOR,MF,1/4W,33.2K,1%  
RESISTOR,MF,1/4W,475,1%  
5 OZ.  
2
X4, X10, X14  
N.A.  
X5  
X6, X9  
X7, X12, X13, X16  
X8  
R11, R17, R21, R22,  
R24, R29, R31, R32,  
R33, R34, R38, R46,  
R56, R61, R68, R70,  
R84, R96, R97, R99,  
R106, R109, R115,  
R119, R123, R126,  
R127, R130, R132,  
R133, R157, R159,  
R160, R163, R175,  
R203, R204, R209,  
R212, R240, R246,  
R247, R250, R253,  
R254, R255, R289,  
R290, R293, R294,  
R296, R297, R298,  
R299, R300, R302,  
R321, R332, R352,  
R353, R354, R358  
R12, R25, R26, R58,  
R67, R89, R95, R125,  
R134, R158, R211,  
R242, R251, R281  
R13, R88  
X15  
X17  
X18  
X19  
Y1  
ROM ASSEMBLY (SS)  
N.A.  
N.A.  
IC,ARRAY,DRIVER,PERIPHERAL,NPN,DARL  
IC,CMOS,UNDERVOLT-SENSING,RESET,MCU(SS)  
IC,OP-AMP,QUAD,HIGH-PERF,1014  
NOTES:  
N.A. CAUTION: THIS DEVICE IS SUBJECT TO DAMAGE BY STATIC ELECTRICITY. SEE E2454  
BEFORE HANDLING.  
CRYSTAL,QUARTZ,4.0000MHZ,HC-18/U  
N.B. KEEP THIS AREA FREE OF ENCAPSULATION MATERIAL (‡ .50 MIN.) BOTHSIDESOF  
BOARD.  
N.C. SQUEEZE COMPONENTS TOGETHER BEFORE APPLYING ITEM 2 AND / OR  
ENCAPSULATIONMATERIAL.  
N.D. APPLY ITEM 2 ON COMPONENT SIDE ONLY, AS SHOWN.  
N.E. APPLY ITEM 2 ON BOTH SIDES OF BOARD AS SHOWN, EXCEPT TOP SURFACE OF  
TRIMMER.  
62  
S19400-1002  
RESISTOR,MF,1/4W,10.0K,1%  
UNLESS OTHERWISE SPECIFIED:  
CAPACITANCE = MFD/VOLTS  
INDUCTANCE = HENRIES  
RESISTANCE = OHMS  
N.F. KEEP TOP SURFACE OF TRIMMER FREE OF ENCAPSULATION MATERIAL INCLUDING RTV.  
P.C. BOARD BLANK REFERENCE INFORMATION  
BUY BLANK COMPLETE AS G3909-H (4 LAYER BOARD PER E3281)  
(MAKES 2 BOARDS PER PANEL, SEE ELECTRONIC FILE FOR ADDITIONAL INFORMATION)  
ENCAPSULATE WITH E1844  
MAKE PER E1911-ROHS  
TEST PER E3937-C  
14  
2
S19400-2212  
T14648-4  
RESISTOR,MF,1/4W,22.1K,1%  
RESISTOR,WW,5W,40,5%,SQ  
R14, R18, R141, R142,  
R143, R144, R145,  
R146, R147, R148,  
R149, R150, R151,  
R152, R153, R154,  
R155, R156  
R15, R19, R47, R48,  
R49, R50, R51, R52,  
R53, R54, R308, R311  
SCHEMATIC REFERENCE G3908-2H1  
18  
12  
S19400-47R5  
S19400-10R0  
RESISTOR,MF,1/4W,47.5,1%  
RESISTOR,MF,1/4W,10.0,1%  
FOR PARTS ORDERS:  
INCLUDE(1)S2559P7RINT PARTS ORDERS  
INSTRUCTION SHEET.  
ALL COMPONENTS ANDMATERIALS USED IN THIS  
ASSEMBLYARE TO BE RoHS COMPLIANT PER E4253.  
MANUFACTURED AS:  
G 3  
PART NUMBER IDENTIFICATION CODE  
THIS DOCUMENT CONTAINS PROPRIETARY INFORMATION OWNED BY LINCOLN GLOBAL, INC. AND MAY NOT BE DUPLICATED, COMMUNICATED  
TO OTHER PARTIES OR USED FOR ANY PURPOSE WITHOUT THE EXPRESS WRITTEN PERMISSION OF LINCOLN GLOBAL, INC.  
PROPRIETARY & CONFIDENTIAL:  
UNLESS OTHERWISE SPECIFIED TOLERANCE  
MANUFACTURING TOLERANCE PER E2056  
9
0
9
-
2
H
1
DESIGN INFORMATION  
REFERENCE:  
EQUIPMENT TYPE:  
SUBJECT:  
PAGE _1__ OF ___  
1
PRECISION TIG  
CONTROL P.C. BOARD ASSEMBLY  
ON 2 PLACE DECIMALS IS ± .02  
FEI  
-
DRAWN BY:  
ENGINEER:  
APPROVED:  
G3909-1  
SCALE:  
ON  
3
PLACE DECIMALS IS  
±
.002  
DOCUMENT  
DOCUMENT  
NUMBER:  
ON ALL ANGLES IS ± .5 OF A DEGREE  
REVISION:  
MATERIAL TOLERANCE (" ") TO AGREE  
t
WITH PUBLISHED STANDARDS.  
MATERIAL  
DISPOSITION:  
APPROV AL  
DATE:  
PROJECT  
NUMBER:  
G3909-2  
CRM36844  
UF  
C
3/29/2007  
1:1  
DO NOT SCALE THIS DRAWING  
STRP  
NOTE: Lincoln Electric assumes no responsibility for liablilities resulting from board level troubleshooting. PC Board repairs will invalidate your factory warranty. Individual Printed Circuit Board Components are not available from Lincoln Electric. This information is pro-  
vided for reference only. Lincoln Electric discourages board level troubleshooting and repair since it may compromise the quality of the design and may result in danger to the Machine Operator or Technician. Improper PC board repairs could result in damage to the  
machine.  
®
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
G-13  
G-13  
ELECTRICAL DIAGRAMS  
SCHEMATIC - CONTROL PC BOARD - ABOVE CODE 11000 (G4762 PAGE 1)  
NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual.  
®
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
G-14  
G-14  
ELECTRICAL DIAGRAMS  
SCHEMATIC - CONTROL PC BOARD - ABOVE CODE 11000 (G4762 PAGE 2)  
NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual.  
®
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
G-15  
G-15  
ELECTRICAL DIAGRAMS  
SCHEMATIC - CONTROL PC BOARD - ABOVE CODE 11000 (G4762 PAGE 3)  
NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual.  
®
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
G-16  
G-16  
ELECTRICAL DIAGRAMS  
SCHEMATIC - CONTROL PC BOARD - ABOVE CODE 11000 (G4762 PAGE 4)  
NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual.  
®
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
G-17  
G-17  
ELECTRICAL DIAGRAMS  
SCHEMATIC - CONTROL PC BOARD - ABOVE CODE 11000 (G4762 PAGE 5)  
NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual.  
®
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
G-18  
G-18  
ELECTRICAL DIAGRAMS  
PC BOARD ASSEMBLY-CONTROL - ABOVE CODE 11000 (G4763-1)  
1 3 - 7 6 G 4  
ITEM  
QTY PART NUMBER DESCRIPTION  
R15, R19, R47, R48, R49,  
R50, R51, R52, R53, R54,  
R308, R311  
CHANGE DETAIL: RELEASED FROM X A.02  
ENGINEERING CONTROLLED  
MANUFACTURER: No  
1
1
4
4
G4763-A  
CF000003  
E106A-13  
PC BOARD BLANK  
12  
43  
S19400-10R0  
RESISTOR,MF,1/4W,10.0,1%  
2
3
4
5
6
7
8
9
(TRI1, TR!2, X5, X9)*  
6-32 X .375 ROUND HEAD MACHINE SCREW  
(TRI1, TRI2, X5, X9)*  
(TRI1, TRI2, X5, X9)*  
(TRI1, TRI2, X5, X9)*  
#
6
LOCK WASHER  
R17, R20, R21, R22, R29,  
R40, R41, R44, R55, R56,  
R58, R75, R76, R136,  
R176, R210, R213, R214,  
R241, R275, R282, R287,  
R288, R291, R319, R323,  
R325, R329, R330, R331,  
R359, R366, R375, R378,  
R379, R383, R404, R406,  
R407, R408, R409, R412,  
R418  
AS REQ E1868  
THERMO JOINT COMPOUND  
HEAT SINK,ALUMINUM,EXTRUDED,FOR  
SUPPORT,PCB,SNAP=IN,063,WHT  
SEALANT  
4
2
S18104-3  
S19300-7  
1
TO-220  
5.0 OZ E2861  
1
1
S26860-1  
S26861-1  
PSOC SOFTWARE  
PS OC SOFTWARE  
S19400-4751  
RESISTOR,MF,1/4W,4.75K,1%  
REFER TO ELECTRONIC COMPONENT DATABASE FOR SPECIFICATIONS ON ITEMS LISTED BELOW  
REFERENCES  
QTY PART NUMBER DESCRIPTION  
C1, C7, C178, C179  
C2, C5, C17, C21, C25,  
C28, C36, C41, C46, C50,  
C57, C61, C69, C70, C71,  
C76, C77, C78, C85, C86,  
C89, C90, C103, C105,  
C106, C122, C123, C124,  
C125, C129, C130, C139,  
C148, C149, C157, C158,  
C165, C167, C168, C169,  
C171, C172, C173, C176,  
C177  
C6, C16, C20, C35, C59,  
C100, C118, C143, C155  
C8, C9, C11, C26, C27,  
C32, C42, C44, C56, C65,  
C66, C67, C68, C83, C87,  
C92, C101  
4
S16668-8  
CAPACITOR,CEMO,330pF,100V,5%  
R24, R39, R46, R84, R97,  
R109, R119, R123, R126,  
R127, R130, R132, R133,  
R159, R160, R163, R175,  
R203, R204, R209, R212,  
R240, R246, R247, R250,  
R253, R289, R293, R294,  
R296, R297, R299, R300,  
R302, R321, R332, R352,  
R353, R358, R384, R386,  
R394, R403, R4  
R25, R67, R125, R134,  
R158, R211, R242, R251,  
R281, R392, R419  
R38, R254, R298, R313,  
R387, R411, R415  
R42, R128, R164, R169,  
R215, R216, R245, R260,  
R261, R339  
45  
S19400-1002  
RESISTOR,MF,1/4W,10.0K,1%  
45  
S16668-11  
CAPACITOR,CEMO,0.1, 50V,10%  
9
S13490-42  
S16668-6  
CAPACITOR,TAEL,1.0,35V,10%  
11  
7
S19400-2212  
S19400-9091  
S19400-4752  
RESISTOR,MF,1/4W,22.1K,1%  
RESISTOR,MF,1/4W,9.09K,1%  
RESISTOR,MF,1/4W,47.5K ,1%  
17  
CAPACITOR,CEMO,4700pF,50V,10%  
C10, C24, C58  
C14, C15, C141  
3
3
S16668-3  
S13490-181  
CAPACITOR,CEMO,100pF, 100V,5%  
CAPACITOR,ALEL,22,63V,20%  
10  
C18, C19, C37, C38, C62,  
C72, C73, C74, C75, C79,  
C80, C88, C91, C104,  
C107, C112, C128, C134,  
C142, C144, C145, C146,  
C147, C150, C151, C152,  
C153, C154, C156, C159,  
C170  
C22, C51  
C23, C52  
C53  
C60  
C81, C82, C98, C99,  
C117, C131, C133, C135,  
C136, C137, C140, C160,  
C161, C162, C163  
C84  
C95, C96, C97  
C102, C138  
C113, C114, C115, C116  
C119, C120  
C121  
R43  
1
5
2
5
4
S19400-2213  
S19400-2002  
S19400-2210  
S19400-3321  
S19400-26R7  
RESISTOR,MF,1/4W,221K,1%  
RESISTOR,MF,1/4W,20.0K,1%  
RESISTOR,MF,1/4W,221,1%  
RESISTOR,MF,1/4W,3.32K,1%  
RESISTOR,MF,1/4W,26.7,1%  
R45, R66, R85, R108,  
R171  
R57, R371  
R59, R252, R259, R377,  
R389  
R72, R101, R102, R276  
R73, R74, R131, R135,  
R170, R205, R270, R292,  
R295  
1
N.G.  
8
31  
S16668-5  
CAPACITOR,CEMO,.022,50V,20%  
N.B.  
6
N.J.  
1.20  
N.K.  
2
3
4
5
N.D.  
N.F.  
N.C.  
N.D.  
16.80  
2
2
1
1
T11577-54  
S13490-183  
S13490-92  
S16668-7  
CAPACITOR,CD,750PF,1000V,10%  
CAPACITOR,ALEL,120MF,50V,20%  
CAPACITOR,ALEL,3300, 50V,+30/-10%  
CAPACITOR,CEMO,820pF,50V,5%  
9
S19400-1003  
RESISTOR,MF,1/4W,100K,1%  
10.68  
R77, R385  
R78  
R79  
2
1
1
S19400-6811  
S19400-3921  
S19400-3011  
RESISTOR,MF,1/4W,6.81K,1%  
RESISTOR,MF,1/4W,3.92K,1%  
RESISTOR,MF,1/4W,3.01K,1%  
6.00  
5.80  
15  
T11577-52K  
CAPACITOR,CD,.0047/.005,1400V,20%  
R83, R87, R118, R168,  
R248, R249, R277, R280  
R92, R103, R104, R129,  
R140, R161, R179, R202,  
R206, R207, R239, R243,  
R263, R267, R273, R274,  
R279, R305, R312, R314,  
R315, R320, R364, R388,  
R396, R400, R405, R410  
R98, R177, R278, R336,  
R395  
X X X X  
C1  
DZ1  
D12  
C6  
8
S19400-1004  
RESISTOR,MF,1/4W,1.00M,1%  
R423  
DZ2 4  
R9  
C2  
D1  
C7  
R18  
R420  
R416  
D2  
R401  
R13  
R16  
R21  
J14  
R24  
J13  
1
3
2
4
2
1
1
1
S13490-40  
T11577-46K  
S16668-9  
S13490-81  
S16668-2  
S13490-19  
S13490-186  
S16668-1  
CAPACITOR,TAEL,2.7,50V,10%  
DZ3  
C10  
R20  
R17  
R8  
C9  
D10  
R2  
C23  
R40  
C17  
R41  
D13  
R43  
X
X
X
X
X
X
X
X
Q7  
R415  
R373  
R374  
CAPACITOR,CD,.05,600V,+80/-20%  
CAPACITOR,CEMO,150pF, 100V,5%  
CAPACITOR,PEF,0.1MF,400V,10%,RADIAL  
CAPACITOR,CEMO,47pF, 100V,5%  
CAPACITOR,TAEL,1.8,20V,10%  
R19  
R51  
R52  
R53  
R398  
R377  
C18  
C19  
D35  
C179  
R381  
R365  
X X X X X X  
R14  
C8  
C21  
C175  
R417  
C177  
R418  
R421  
R422  
X
X
X
X
X
X
C11  
R25  
C20  
R77  
R78  
R44  
R45  
R83  
R84  
R85  
R66  
XXX  
R400  
28  
S19400-1001  
RESISTOR,MF,1/4W,1.00K,1%  
R372  
C172  
R73  
R74  
D11  
D22  
D93  
R42  
R79  
Q2  
R15  
R47  
R48  
R49  
C176  
R406  
C171  
R376  
R405  
R387  
D91  
DZ2 6  
R59  
C27  
C38  
D26  
D17  
R54  
R407  
DZ4  
R72  
C16  
D21  
R404  
R395  
DZ2 5  
Q1  
Q6  
Q10  
Q11  
R39  
R403  
DZ2 7  
C35  
D20  
C132  
C175  
CAPACITOR,ALEL,1800,160V,20%  
CAPACITOR,CEMO,22pF, 100V,5%  
R58  
R75  
R76  
DZ2 8  
R386  
R384  
R38  
R411  
D95  
R50  
D16  
C5  
C25  
C28  
C44  
R91  
Q3  
R368  
R366  
R402  
C53  
R87  
5
6
S19400-4750  
S19400-5110  
RESISTOR,MF,1/4W,475,1%  
RESISTOR,MF,1/4W,511,1%  
R383  
R385  
D1, D16, D17, D18, D20,  
D21, D28, D36, D37, D38,  
D39, D90  
X
X
R22  
C41  
R410  
R391  
R392  
R101  
R108  
C178  
C36  
R408  
R369  
G4763-1  
Q17  
D31  
Q5  
Q4  
12  
T12705-34  
DIODE,AXLDS,1A,400V,FR,1N4936  
R102  
R103  
R129  
R57  
R100, R271, R334, R337,  
R340, R341  
R110, R111  
D28  
C50  
C42  
C167  
C51  
R109  
Q18  
R104  
C58  
Q21  
PRECISION TIG CONTROL  
R367  
R116  
R112  
C46  
DZ5  
R110  
R111  
N.D.  
R55  
C24  
D94  
C37  
2
1
4
S19400-2001  
S19400-9092  
S19400-7681  
RESISTOR,MF,1/4W,2.00K,1%  
RESISTOR,MF,1/4W,90.9K,1%  
RESISTOR,MF,1/4W,7.68K,1%  
T1  
T2  
R132  
R133  
R130  
R131  
C60  
D2, D10, D11, D12, D13,  
D14, D19, D22, D25, D26,  
D31, D35, D40, D41, D42,  
D51, D54, D55, D58, D59,  
D60, D61, D64, D65, D66,  
D67, D72, D73, D79, D80,  
D81, D82, D83, D84, D85,  
D86, D87, D89, D96  
R120  
R92  
XXX  
R126  
R122  
R123  
R112  
R56  
R121  
R117  
D40  
R359  
C56  
D42  
C89  
R127  
Q19  
R128  
D46  
D48  
D49  
OCI1  
R139  
R121, R124, R244, R318  
R137, R138, R181, R217,  
R262, R304  
R139, R180, R218, R264  
R162, R173, R333, R338,  
R372, R373, R374  
R165  
R166  
R167, R301  
R178  
R182, R183, R184, R185,  
R186, R187, R188, R189,  
R190, R191, R192, R193,  
R194, R195, R196, R197,  
R198, R199, R200, R201,  
R219, R220, R221, R222,  
R223, R224, R225, R226,  
R227, R228, R229, R230,  
R231, R232, R233, R234,  
R235, R236, R237, R238  
R265, R266, R306, R351  
R268, R309, R343, R346  
R269, R307  
R272  
R286, R328  
R303  
R310  
R316  
R322  
R335, R342, R344, R345,  
R347, R365, R381  
R348, R349, R362, R363  
R357  
R361, R367, R368  
R382  
R391  
R401  
R414  
T1, T2  
R3  
C62  
R135  
R136  
Q20  
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
D41  
R119  
DZ6  
R125  
X
X
X
X
X
X
X
R389  
R390  
R396  
X
X
X
X
X
X
X
C1  
4
R134  
R175  
C59  
C57  
XXX  
D36  
D37  
D38  
D39  
R167  
C92  
C61  
D47  
6
4
7
S19400-1211  
S19400-2670  
S19400-3320  
RESISTOR,MF,1/4W,1.21K,1%  
RESISTOR,MF,1/4W,267,1%  
RESISTOR,MF,1/4W,332,1%  
R124  
R163  
R164  
C72  
39  
T12199-1  
DIODE,AXLDS,1A,400V  
R140  
C80  
R118  
D51  
C76  
C77  
R180  
R419  
C74  
R205  
R170  
C75  
Q23  
C70  
D54  
R179  
C79  
C165  
R160  
D61  
R394  
X X  
X X  
R161  
R162  
R375  
X X  
C69  
C83  
C78  
R173  
C82  
C99  
N.C.  
R203  
R165  
R169  
C73  
X
X
X
X
X
R358  
D96  
X
X
X
X
X
C81  
X
X
X
X
X
X
R29  
D19  
R67  
R176  
D7  
R177  
C71  
D62  
R215  
R216  
R260  
R261  
C97  
R159  
D60  
1
1
2
1
S19400-3323  
S19400-5621  
S19400-1501  
T14648-24  
RESISTOR,MF,1/4W,332K,1%  
RESISTOR,MF,1/4W,5.62K,1%  
RESISTOR,MF,1/4W,1.50K,1%  
RESISTOR,WW,5W,0.5,5%,SQ  
R166  
D63  
D64  
R204  
R211  
D55  
R212  
D58  
X
X
X
X
R409  
D92  
D89  
C173  
C91  
Q22  
D7, D91, D92, D93, D94,  
D95  
D46, D47, D48, D49, D50  
D62, D63  
D68, D69, D70, D71  
DZ1, DZ3, DZ9, DZ29  
DZ4, DZ12, DZ13, DZ26,  
DZ27, DZ28  
DZ5, DZ20  
C84  
XXXX  
C96  
R202  
6
T12705-64  
DIODE,SCHOTTKY,AXLDS,0.2A,30V,BAT42  
R209  
R210  
R213  
C98  
R218  
R357  
R388  
C32  
N.C.  
R158  
R246  
R247  
R361  
C105  
DZ9  
R291  
R292  
5
2
4
4
T12705-14  
T12705-23  
T12199-2  
T12702-29  
DIODE,AXLDS,3A,200V,1N5402  
DIODE,SCHOTTKY,AXLDS,1A,30V,1N5818  
DIODE,AXLDS,1A,1000V  
D65  
D59  
R214  
R295  
R4  
R259  
Q27  
R315  
C86  
C106  
R252  
R263  
C112  
C103  
Q25  
X X  
R248  
R249  
C85  
C168  
ZENER DIODE,1W,15V,5%,1N4744A  
DZ1 0  
C123  
R251  
C107  
R244  
R276  
D67  
N.D.  
R245  
C102  
R293  
R100  
X
X
X
R264  
R266  
6
T12702-27  
ZENER DIODE,1W,10V,5%,1N4740A  
X
X
R270  
R271  
R272  
R273  
C119  
R311  
X
X
OCI6  
R269  
C125  
R304  
R277  
R278  
C120  
R413  
R412  
R305  
C134  
40  
S19400-68R1  
RESISTOR,MF,1/4W,68.1,1%  
2
2
3
T12702-53  
T12702-19  
T12702-23  
ZENER DIODE,1W,3.3V,5%,1N4728A  
ZENER DIODE,1W,12V,5%,1N4742A  
ZENER DIODE,5W,15V,5%,1N5352B  
X
R6  
X
X
R336  
C121  
R280  
X X X  
DZ6, DZ10  
XXXXXXXXX  
R265X  
XXX  
X
X
C151  
X
X
X
X
R274  
R312  
C144  
R313  
C156  
R414  
DZ7, DZ8, DZ14  
DZ15, DZ16, DZ17, DZ18,  
DZ19  
DZ23, DZ24, DZ25  
J2, J3  
J4, J10  
J5, J13, J5A  
J6  
J7, J8, J12  
J9  
J11  
J14  
L1, L2  
OCI1, OCI2, OCI5, OCI8  
OCI3, OCI4  
OCI6, OCI7  
Q1, Q4, Q18  
OCI7  
C135  
TP4  
N.C., N.D.  
DZ1 7  
R279  
R316  
R317  
R318  
5
T12702-52  
ZENER DIODE,1W,5.1V,5%,1N4733A  
XXX  
D81  
D82  
TP9  
TP11  
TP12  
X
X
X
X
TP7  
X
R306  
3
2
2
3
1
3
1
1
1
2
4
2
2
3
T12702-45  
S21134-10  
S24020-10  
S24020-8  
S24020-2G  
S24020-6  
S24020-12  
S24020-16  
S18248-4  
T12218-9  
ZENER DIODE,1W,18V,5%,1N4746A  
XXXX  
XXXX  
4
4
2
1
2
1
1
1
1
S18380-1  
THERMISTOR,PTC,56 OHMS,90MA  
RESISTOR,MF,1/4W,249,1%  
TP10  
X
R351  
C141  
XXXX  
CONNECTOR,MOLEX,MINI,BLIND,F,10-PIN  
CONNECTOR,MOLEX,MINI,PCB,10-PIN,TIN  
CONNECTOR,MOLEX,MINI,PCB,8-PIN,TIN  
CONNECTOR,MOLEX,MINI,PCB,2-PIN,GOLD  
CONNECTOR,MOLEX,MINI,PCB,6-PIN,TIN  
CONNECTOR,MOLEX,MINI,PCB,12-PIN,TIN  
CONNECTOR,MOLEX,MINI,PCB,16-PIN,TIN  
CONNECTOR,MOLEX,MINI,PCB,4-PIN  
CHOKE,RF,390UH,5%, 225MA,CONFORMAL  
OPTOCOUPLER,TRIAC,DRIVER,ZVC,3083  
OPTOCOUPLER,TRIAC,DRV,RANDOM,800V  
OPTOCOUPLER,PHOTO-Q,70V,CNY17-3  
TRANSISTOR,PNP,TO226,0.5A, 40V,2N4403  
TP5  
TP6  
C143  
R314  
R321  
C163  
R335  
S19400-2490  
S19400-2673  
S19400-3922  
S19400-2802  
S18380-3  
S19400-6810  
S19400-3012  
S19400-3570  
D87  
C157  
R275  
D83  
C150 X X X X  
X X X X X  
X
J12  
X
RESISTOR,MF,1/4W,267K,1%  
RESISTOR,MF,1/4W,39.2K,1%  
RESISTOR,MF,1/4W,28.0K,1%  
THERMISTOR,PTC,.08-0.19 OHMS,1.85A  
RESISTOR,MF,1/4W,681,1%  
N.C.,N.D.  
R7  
X
X
X
X X X X  
X X X X  
X X X X  
X X  
X X X X  
X
X
X
N.F.  
J11  
J4  
J5  
J5A  
J6  
J7  
J8  
J10  
J9  
X X X X X X  
X X X X X  
X X X X  
X
X X X X X X X  
X X  
X X X  
X
X X X X X X  
X X X X X X  
.20  
0
RESISTOR,MF,1/4W,30.1K,1%  
RESISTOR,MF,1/4W,357,1%  
S15000-16  
S15000-31  
S15000-10  
T12704-69  
7
S19400-2000  
RESISTOR,MF,1/4W,200,1%  
N.C., N.D.  
N.C., N.D.  
N.F.  
4
1
3
1
1
1
1
2
4
1
S19400-20R0  
S19400-1502  
S19400-2211  
S19400-1500  
S19400-5622  
T10812-79  
S18380-5  
T12737-2  
T13640-25  
T13640-16  
RESISTOR,MF,1/4W,20.0,1%  
RESISTOR,MF,1/4W,15K,1%  
RESISTOR,MF,1/4W,2.21K,1%  
RESISTOR,MF,1/4W,150,1%  
RESISTOR,MF,1/4W,56.2K,1%  
TRIMMER,ST,1/2W,100, 10%,LINEAR  
THERMISTOR,PTC,0.5-1.17 OHMS,0.5A  
TRANSFORMER,PULSE,3-WINDING,1:1:1  
MOV,130VRMS,90J,20MM  
N.C., N.D.  
9
N.H.  
N.D.  
N.C.,N.D.  
N.F.  
17.80  
18.00  
N.D.  
.20  
Q2, Q3, Q5, Q6, Q7, Q12,  
Q13, Q16, Q17, Q19,  
Q20, Q21, Q22, Q23,  
N.C.  
N.E.  
0
6.00  
12.00  
19  
T12704-68  
TRANSISTOR,NPN,TO226,0.5A,40V,2N4401  
Q24, Q26, Q27, Q28, Q29  
Q10, Q11  
Q25  
R2  
R3, R5  
R4, R7  
R6  
2
1
1
2
2
1
T12704-54  
T12704-73  
T10812-41  
S16296-3  
T10812-73  
S16296-5  
TRANSISTOR,NMF,TO220,15A,60V,(SS)  
TRANSISTOR,NMF,4-PIN DIP,1A,100V,IRFD110(SS)  
TRIMMER,ST,1/2W,10K, 10%,LINEAR  
TRIMMER,MT,1/2W,500, 10%,LINEAR  
TRIMMER,ST,1/2W,2K, 10%,LINEAR  
N.A.  
N.A.  
N.K.,N.L.  
TP1, TP3, TP5, TP6  
TP2  
TP4, TP7, TP9, TP10,  
TP11, TP12  
MOV,150VRMS,80J,20MM  
6
T13640-18  
MOV,320VRMS,150J,20MM  
TRIMMER,MT,1/2W,10K, 10%,LINEAR  
NOTES:  
TP8  
1
4
1
1
2
1
4
1
1
1
1
2
T13640-11K  
S15161-27  
S17900-24  
S17900-8  
S15018-6  
S15128-6  
S15128-18  
S15128-15  
S15018-4  
M15102-4  
S15128-16  
S25073-9  
MOV,150VRMS,45J,14MM  
TRIAC,TO220,8A,800V  
R8, R16, R120, R122,  
R172, R317, R356, R369,  
R376, R380, R402  
R9, R91, R116, R117,  
R350  
11  
S19400-1000  
RESISTOR,MF,1/4W,100,1%  
TRI1, TRI2, TRI3, TRI4  
X1  
X2  
X4, X14  
X5  
X8, X12, X13, X16  
X9  
X11  
X17  
X19  
N.A. CAUTION: THIS DEVICE IS SUBJECT TO DAMAGE BY STATIC ELECTRICITY. SEE E2454  
BEFORE HANDLING.  
IC,CMOS,GATE,NAND,2-INPUT,QUAD,SCHM(SS)  
IC,CMOS,INVERTER,SCHMITT,HEX,HC14A(SS)  
IC,CMOS,SWITCH,ANALOG,QUAD, 4066(SS)  
IC,VOLT REG,FIXED,3-T,(+),1A,15V,TO220  
OP-AMP,QUAD, HIGH-PERF,33074  
IC,VOLT REG,ADJ,3-T,(+),3A,350,TO220  
IC,CMOS,INVERTER,SCHMITT, HEX,4584(SS)  
IC,ARRAY,DRIVER,PERIPHERAL,NPN,DARL  
IC,OP-AMP,QUAD,HIGH-PERF,1014  
N.A.  
N.A.  
N.A.  
5
1
S19400-3322  
T14648-4  
RESISTOR,MF,1/4W,33.2K,1%  
RESISTOR,WW ,5W,40,5%,SQ  
N.B. KEEP THIS AREA FREE OF ENCAPSULATION MATERIAL (‡ .50 MIN.) BOTH SIDES OF  
BOARD.  
N.C. SQUEEZE COMPONENTS TOGETHER BEFORE APPLYING ITEM 7 AND / OR  
ENCAPSULATION MATERIAL.  
N.D. APPLY ITEM 7 ON COMPONENT SIDE ONLY, AS SHOWN.  
N.E. APPLY ITEM 7 ON BOTH SIDES OF BOARD AS SHOWN, EXCEPT TOP SURFACE OF  
TRIMMER. MAXIMUM ITEM 7 HEIGHT NEAR CONNECTOR J2 IS .50 INCHES.  
N.F. KEEP TOP SURFACE FREE OF ENCAPSULATION MATERIAL INCLUDING RTV.  
N.G. PROGRAM X20 WITH ITEM 8 AND LABEL X20 WITH PART NO. OF ITEM 8.  
N.H. PROGRAM X21 WITH ITEM 9 AND LABEL X21 WITH PART NO. OF ITEM 9.  
N.J. COVER WITH TAPE AFTER PROGRAMMING.  
R13  
R14, R18, R141, R142,  
R143, R144, R145, R146,  
R147, R148, R149, R150,  
R151, R152, R153, R154,  
R155, R156, R390, R398,  
R413, R420, R421, R422,  
R423  
N.A.  
N.A.  
25  
S19400-47R5  
RESISTOR,MF,1/4W,47.5,1%  
N.A.  
N.A.  
X20, X21  
IC,CMOS,PSOC,8-BIT,CY8C27443,DIP-28(SS)  
UNLESS OTHERWISE SPECIFIED:  
CAPACITANCE = MFD/VOLTS  
INDUCTANCE = HENRIES  
RESISTANCE = OHMS  
N.K. APPLY ITEM 7 ON COMPONENT SIDE ONLY, AS SHOWN. MAXIMUM ITEM 7 HEIGHT IS .50  
INCHES.  
N.L. APPLY ITEM 7 TO CONNECTOR’S PLASTIC MOUNTING PINS ON NON-COMPONENT SIDE.  
REVISION CONTROL  
G4763-1A1  
PART NO. IDENTIFICATION  
CODE  
ALL COMPONENTS AND MATERIALS USED IN THIS  
ASSEMBLY ARE TO BE RoHS COMPLIANT PER E4253  
TEST PER E4298-C  
COAT WITH E1844 AND E3668  
SCHEMATIC REFERENCE: G4762-1A1  
MAKE DETAIL  
MANUFACTURE PER E1911  
BUY BLANK COMPLETE  
( 2 BOARDS PER PANEL)  
FOR PARTS ORDERS:  
4 LAYER BOARD BLANK PANEL  
SEE ELECTRONIC FILE FOR ADDITIONAL INFORMATION.  
INCLUDE (1) S25597PRINT PARTS ORDERS  
INSTRUCTION SHEET.  
THIS DOCUMEN T CON TAINS PROPRIETARY  
INFORMATION O WNED BY LINCOLN G LOBAL, INC. AND MA  
Y NOT BE DUPLICATED, COM  
MUNICATED  
PROPRIETARY & CONFIDENTIAL:  
TO O THER PARTIES OR USED FOR AN  
Y PURPOSE WITHOU  
T THE EXPRESS WRIT  
TEN PERMISSION OF LINCOLN GL OBAL, INC.  
UNLESS OTHERWISE SPECIFIED TOLERANCE  
DESIG  
N
INF OR MATIO  
N
REFERENCE:  
G3909  
SCA LE:  
MANUF ACTURING TOLERANC PER E2056  
ON 2 PLA CE DE CIMA LS IS .02  
ON PLACE DEC IMALS IS .002  
.5 OF A DE GREE  
E
EQUIPMENT TYPE:  
SUBJECT:  
PAGE _1__ OF ___  
1
PRECISION TIG  
±
JB  
DRAWN BY:  
ENGI NEER:  
3
±
DOCUMENT  
DOCUMENT  
NUMBER:  
ON AL L A NGLES IS  
±
CONTROL P.C. BOARD ASSEMBLY  
REVISION:  
TNguyen  
-
MATER IAL T OLE RA NCE (" ") TO AG REE  
t
WITH PUB LIS HE D STAN DA RDS.  
MATERIAL  
APPROVAL  
DATE:  
PROJECT  
NUMBER:  
G4763-1  
CRM38261  
NA  
A
APPR OVED:  
7-27-2007  
1:1  
DISPOSITION:  
DO NOT SCAL E THI S DR AWING  
STRP  
NOTE: Lincoln Electric assumes no responsibility for liablilities resulting from board level troubleshooting. PC Board repairs will invalidate your factory warranty. Individual Printed Circuit Board Components are not available from Lincoln Electric. This information is pro-  
vided for reference only. Lincoln Electric discourages board level troubleshooting and repair since it may compromise the quality of the design and may result in danger to the Machine Operator or Technician. Improper PC board repairs could result in damage to the  
machine.  
®
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
G-19  
G-19  
ELECTRICAL DIAGRAMS  
SCHEMATIC-PROTECTION P.C. BOARD (M16115)  
1 6 1 M 1 5  
L4  
J23  
J22  
J22  
J22  
J22  
J22  
J22  
1
2
3
4
5
5
4
1
2
6
3
.39mH  
C4  
.0047  
3000V  
L5  
J23  
J23  
J23  
J23  
.39mH  
C5  
.0047  
3000V  
L1  
.39mH  
C1  
.0047  
3000V  
L2  
.39mH  
C2  
.0047  
3000V  
L6  
.39mH  
C6  
.0047  
3000V  
L3  
J23  
J23  
7
.39mH  
C3  
.0047  
3000V  
8
GENERAL INFORMATION  
LAST NO. USED  
R-  
C-  
D-  
_
_
_
ELECTRICAL SYMBOLS PER E1537  
CAPACITORS =  
MFD ( .022/50V  
UNLESS OTHERWISE SPECIFIED)  
LABELS  
RESISTORS = Ohms (  
1/4W UNLESS OTHERWISE SPECIFIED)  
(UNLESS OTHERWISE SPECIFIED)  
DIODES =  
1A, 400V  
SUPPLY  
VOLTAGE NET  
POWER SUPPLY SOURCE POINT  
COMMON CONNECTION  
NOTES :  
N.A. SINCE COMPONENTS OR CIRCUITRY ON A PRINTED CIRCUIT BOARD MAY CHANGE  
WITHOUT AFFECTING THE INTERCHANGEABILITY OF A COMPLETE BOARD, THIS DIAGRAM MAY  
NOT SHOW THE EXACT COMPONENTS OR CIRCUITRY OF CONTROLS HAVING A COMMON CODE  
NUMBER.  
FRAME CONNECTION  
EARTH GROUND CONNECTION  
UNLESS OTHERWISE SPECIFIED TOLERANCE  
ON HOLE SIZES PER E2056  
ON 2 PLACE DECIMALS IS .02  
THIS SHEET CONTAINS PROPRIETARY INFORMATION  
EQUIP.  
SQARE WAVE TIG 350  
THE LINCOLN ELECTRIC CO.  
CLEVELAND, OHIO U.S.A.  
TYPE  
OWNED BY  
AND IS  
5-29-90SPA  
THE LINCOLN ELECTRIC CO.  
NOT TO BE REPRODUCED, DISCLOSED OR USED  
WITHOUT THE EXPRESS PERMISSION OF  
ON 3 PLACE DECIMALS IS .002  
ON ALL ANGLES IS .5 OF A DEGREE  
PROTECTION P.C. BOARD SCHEMATIC  
SUBJECT  
NONE  
1-12-90  
SCALE  
SHT.  
t
MATERIAL TOLERANCE (" ") TO AGREE  
THE LINCOLN ELECTRIC CO.  
MK/DRS  
GM/BS  
REF.  
16115  
DR  
M
DATE  
CHK  
SUP'S'D'G  
NO.  
WITH PUBLISHED STANDARDS.  
NOTE: Lincoln Electric assumes no responsibility for liablilities resulting from board level troubleshooting. PC Board repairs will invalidate your factory warranty. Individual Printed Circuit Board Components are not available from Lincoln Electric. This information is pro-  
vided for reference only. Lincoln Electric discourages board level troubleshooting and repair since it may compromise the quality of the design and may result in danger to the Machine Operator or Technician. Improper PC board repairs could result in damage to the  
machine.  
®
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
G-20  
G-20  
ELECTRICAL DIAGRAMS  
PC BOARD ASSEMBLY-PROTECTION (M16062-1)  
-1  
REQ'D  
IDENTIFICATION  
PART NO.  
ITEM  
6
6
1
1
1
T11577-58  
.0047/3000 V  
.39 mH  
HEADER  
C1, C2, C3, C4, C5, C6  
L1, L2, L3, L4, L5, L6  
J22  
J23  
1
T12218-9F  
S18248-6  
S18248-8  
L8081-B  
HEADER  
P.C. BD BLANK  
M16062-1  
9-28-2001M  
CAPACITORS = MFD/VOLTS  
NOTE: Lincoln Electric assumes no responsibility for liablilities resulting from board level troubleshooting. PC Board repairs will invalidate your factory warranty. Individual Printed Circuit Board Components are not available from Lincoln Electric. This information is pro-  
vided for reference only. Lincoln Electric discourages board level troubleshooting and repair since it may compromise the quality of the design and may result in danger to the Machine Operator or Technician. Improper PC board repairs could result in damage to the  
machine.  
®
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
G-21  
G-21  
ELECTRICAL DIAGRAMS  
SCHEMATIC-BYPASS / STABILIZER P.C. BOARD (S22530-1) (CODE 10806 & 10807)  
ARC STABILIZER CAPACITOR  
ARC STABILIZER  
RESISTOR  
15  
C9  
10  
R1  
250V  
5W  
CONNECTION MADE THROUGH  
HOLE WITH SOLDER PAD  
CONNECTION MADE THROUGH  
HOLE WITH SOLDER PAD  
C1  
C2  
C3  
C4  
C5  
C6  
C7  
C8  
TP1  
320V  
160J  
TP2  
320V  
160J  
.05  
.05  
.05  
.05  
.05  
.05  
.05  
.05  
600V  
600V  
600V  
600V  
600V  
600V  
600V  
600V  
Graphic  
Graphic  
GND  
GND CONNECTION MADE THROUGH SOLDER PAD  
AND SCREW TO STEEL STANDOFF ON MACHINE  
S22530-1B0  
Rev A  
NOTES :  
LABELS  
GENERAL INFORMATION  
ELECTRICAL SYMBOLS PER E1537  
N.A.  
SINCE COMPONENTS OR CIRCUITRY ON A PRINTED  
FRAME CONNECTION  
CIRCUIT BOARD MAY CHANGE WITHOUT AFFECTING  
THE INTERCHANGEABILITY OF A COMPLETE BOARD.  
THIS DIAGRAM MAY NOT SHOW THE EXACT COMPONENTS  
OR CIRCUITRY OF CONTROLS HAVING A COMMON CODE NUMBER.  
SUPPLY  
VOLTAGE NET  
MFD  
CAPACITORS =  
(
.022/50V  
1/4W UNLESS OTHERWISE SPECIFIED)  
(UNLESS OTHERWISE SPECIFIED)  
UNLESS OTHERWISE SPECIFIED)  
POWER SUPPLY SOURCE POINT  
COMMON CONNECTION  
RESISTORS = Ohms (  
EARTH GROUND CONNECTION  
DIODES =  
1A, 400V  
NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual.  
®
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
G-22  
G-22  
ELECTRICAL DIAGRAMS  
PC BOARD ASSEMBLY-BYPASS / STABILIZER (L10121-1) (CODE 10806 & 10807)  
L10121-1 BYPASS STABILIZER  
L10121-1  
Rev B  
ITEM  
REQ'D  
IDENTIFICATION  
PART NO.  
NOTE: Lincoln Electric assumes no responsibility for liablilities resulting from board level troubleshooting. PC Board repairs will invalidate your factory warranty. Individual Printed Circuit Board Components are not available from Lincoln Electric. This information is pro-  
vided for reference only. Lincoln Electric discourages board level troubleshooting and repair since it may compromise the quality of the design and may result in danger to the Machine Operator or Technician. Improper PC board repairs could result in damage to the  
machine.  
®
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
G-23  
G-23  
ELECTRICAL DIAGRAMS  
SCHEMATIC-BYPASS AND CE P. C. BOARD (S24206) (CODE 10893)  
2 4 2 0 6  
S
LINE 1 (U)  
B1  
LINE 2 (V)  
B2  
C3  
C4  
2.2  
2.2  
275V  
275V  
C1  
.0047  
440V  
C2  
.0047  
440V  
FRAME GROUND  
FILE NAME: S24206_1AA  
THIS SHEET CONTAINS PROPRIETARY INFORMATION OWNED BY  
NOTES :  
THE LINCOLN ELECTRIC CO.  
GENERAL INFORMATION  
AND IS NOT TO BE REPRODUCED, DISCLOSED OR USED WITHOUT THE EXPRESS PERMISSION OF  
THE LINCOLN ELECTRIC CO.  
LABELS  
N.A.  
SINCE COMPONENTS OR CIRCUITRY ON  
CIRCUIT BOARD MAY CHANGE  
A PRINTED  
ELECTRICAL SYMBOLS PER E1537  
FRAME CONNECTION  
WITHOUT AFFECTING  
SUPPLY  
VOLTAGE NET  
MFD  
CAPACITORS =  
(
.022/50V  
1/4W UNLESS OTHERWISE SPECIFIED)  
(UNLESS OTHERWISE SPECIFIED)  
UNLESS OTHERWISE SPECIFIED)  
THE INTERCHANGEABILITY  
OF A COMPLETE  
SHOW THE EXACT COMPONENTS  
CONTROLS HAVING A COMMON CODE NUMBER.  
BOARD.  
POWER SUPPLY SOURCE POINT  
COMMON CONNECTION  
RESISTORS = Ohms (  
THIS DIAGRAM MAY NOT  
EARTH GROUND CONNECTION  
OR CIRCUITRY OF  
DIODES =  
1A, 400V  
EQUIP.  
TYPE  
Ch'ge.Sht.No.  
UNLESS OTHERWISE SPECIFIED TOLERANCE  
ON HOLES SIZES PER E-2056  
ON 2 PLACE DECIMALS IS + .O2  
ON 3 PLACE DECIMALS IS + .OO2  
ON ALL ANGLES IS + .5 OF A DEGREE  
MATERIAL TOLERANCE ("t") TO AGREE  
WITH PUBLISHED STANDARDS  
THE LINCOLN ELECTRIC CO.  
CLEVELAND, OHIO U.S.A.  
NONE  
9/29/97  
XA  
SCHEMATIC, BYPASS  
SUBJECT  
SUP'S'D'G.  
3-20-98  
SCALE  
DATE  
SHT.  
APM  
DR.  
CHK.  
NO.  
S
24206  
NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual.  
®
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
G-24  
G-24  
ELECTRICAL DIAGRAMS  
PC BOARD ASSEMBLY-BYPASS AND CE (L10882-1) (CODE 10893)  
x
x
x
x
x
x
x x x  
x
x
x
x
ITEM  
REQ'D  
IDENTIFICATION  
PART NO.  
x
x
x
x
x
x x x  
x x  
x
x
x
x
x
x
x
x
x
x
x x  
x
x
x x x x  
x x x x  
x
x
x
x
x
x
x
x xx x  
x
10882-1  
L
x x x x  
3-20-98  
BOTTOM VIEW  
NOTE: Lincoln Electric assumes no responsibility for liablilities resulting from board level troubleshooting. PC Board repairs will invalidate your factory warranty. Individual Printed Circuit Board Components are not available from Lincoln Electric. This information is pro-  
vided for reference only. Lincoln Electric discourages board level troubleshooting and repair since it may compromise the quality of the design and may result in danger to the Machine Operator or Technician. Improper PC board repairs could result in damage to the  
machine.  
®
PRECISION TIG 275  
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G-25  
G-25  
ELECTRICAL DIAGRAMS  
SCHEMATIC - TIG OPTION P.C. BOARD - BELOW CODE 11000 (G4039 PAGE 1)  
NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual.  
®
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
G-26  
G-26  
ELECTRICAL DIAGRAMS  
SCHEMATIC - TIG OPTION P.C. BOARD - BELOW CODE 11000 (G4039 PAGE 2)  
NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual.  
®
PRECISION TIG 275  
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G-27  
G-27  
ELECTRICAL DIAGRAMS  
PC BOARD ASSEMBLY - TIG OPTION P.C. BOARD - BELOW CODE 11000 (G4040-2)  
2
4 0 4 - 0 G  
CHANGE DETAIL: REVISED MANUFACTURER SPECIFICATOI N  
EMNAGNIUNFEAECRTINUGRECRO:NYTResOLLED  
ITEM  
QTY PART NUMBER  
DESCRIPTION  
1
2
1
1
G4040-F  
PC BOARD BLANK  
SOFTWARE CPLD (X3)  
S25409-1  
REFER TO ELECTRONIC COMPONENT DATABASE FOR SPECIFICATIONS ON ITEMS LISTED BELOW  
REFERENCES  
QTY PART NUMB ER  
DESCRIPTION  
C1, C2, C4, C5, C7, C9, C10, C14, C15, C16, C17, C18,  
C19, C21, C22, C23, C24, C26, C27, C28, C29, C30, C31,  
C32, C33, C34, C38, C39, C40, C41, C42, C43, C44, C45,  
44  
S25020-3SMT  
CAPACITOR,SMD,CERAMIC,0.1MF,50V,10%,X7R,S0805  
C47, C49, C50, C51, C52, C53, C54, C55, C56, C57  
C3, C8, C58  
C6, C20  
C11, C12, C13, C35, C36, C37, C46, C48  
C59  
3
2
8
1
1
4
5
1
2
1
2
2
2
5
S25020-2SMT  
S25020-5SMT  
S25020-24SMT  
S25020-12SMT  
S25040-2SMT  
S25049-4SMT  
S25040-5SMT  
S25046-1SMT  
S25046-4SMT  
S24020-12  
CAPACITOR,SMD,CERAMIC,0.022MF,50V,10%,X7R,S0805  
CAPACITOR,SMD,CERAMIC,2700pF,50V,5%,X7R,S0805  
CAPACITOR,SMD,CERAMIC,1.0MF,25V,10% ,X7R,S1206  
CAPACITOR,SMD,CERAMIC,100pF,100V,5%,COG,S0805  
DIODE,SMD,1A,400V,DO-214BA/AC  
DIODE,SMD,SCHOTTKY,DUAL,0.200A,30V,SOT-23  
DIODE,SMD,DUAL,0.200A,70V,UFR  
ZENER DIODE,SMD,0.5W,5.1V, 5%,SOD123  
ZENER DIODE,SMD,0.5W,12V,5%,SOD-123  
CONNECTOR,MOLEX,MINI,PCB,12-PIN,TIN  
D1  
D2, D3, D8, D10  
D4, D5, D6, D7, D9  
DZ1  
REVISION CONTROL  
DZ2, DZ3  
N.D. J1  
N.D. J2, J3  
LED1, LED2  
Q1, Q5  
Q2, Q3, Q4, Q6, Q7  
G4040-2F0  
S21135-10  
CONNECTOR,MOLEX,MINI,BLIND,F,10-PIN  
LED,SMD,GREEN,CLEAR,S1206  
TRANSISTOR,SMD,NMF,SOT-23,0.115A,60V,7002LT1(SS)  
TRANSISTOR,SMD,NPN,0.5A,40V,SOT-23,MMBT4401LT1  
PART NO. IDENTIFCI ATION  
CODE  
S25080-2SMT  
S25051-4SMT  
S25050-1SMT  
TEST PER E3937-AC  
COAT WITH E1844 AND E3668 (1 COAT EACH)  
SCHEMATIC REFERENCE: G4039-2F0  
R1, R13, R26, R66, R87, R93, R105, R126, R163, R164,  
R165, R166, R167  
R2, R3, R4, R5, R8, R12, R43, R47, R68, R88, R90, R108,  
R109, R112, R122, R145, R146, R147, R160  
13  
19  
S25000-4751SMT RESISTOR,SMD,METAL FILM,1/10W,4.75K,1%,S0805  
S25000-1001SMT RESISTOR,SMD,METAL FILM,1/10W,1.00K,1%,S0805  
BUY DETAIL  
MAK E DETAIL  
R6, R10, R14, R16, R17, R18, R21, R28, R29, R32, R33,  
MANUFACTURE PER E1911-ROHS  
BUY BLANK COMPLETE  
(6 BOARDS PER PANEL)  
BUY PER E3867  
R48, R52, R53, R56, R61, R63, R64, R65, R89, R92, R101,  
R102, R103, R104, R107, R116, R120, R123, R128, R130,  
R135, R137, R138, R139, R140, R141, R143, R151, R152,  
R153, R154, R155, R157  
44  
S25000-1002SMT RESISTOR,SMD,METAL FILM,1/10W,10.0K,1%,S0805  
R7  
1
10  
8
3
2
1
3
5
5
1
3
3
4
1
2
1
3
3
2
1
8
5
5
3
2
1
2
1
2
1
1
1
6
1
1
2
1
S25058-1SMT  
TRIMMER,SMD,ST,1/4W,10K,10%,LINEAR  
4LAYER BOARD BLANK PANEL  
SEE ELECTRONIC FILE FOR ADDITIONAL INFORMATION.  
R9, R34, R37, R38, R50, R67, R127, R131, R132, R133  
R11, R42, R49, R51, R111, R134, R161, R162  
R15, R79, R81  
R19, R57  
S25000-5110SMT RESISTOR,SMD,METAL FILM,1/10W,511OHMS,1%,S0805  
S25000-4750SMT RESISTOR,SMD,METAL FILM,1/10W,475OHMS,1%,S0805  
S25000-1372SMT RESISTOR,SMD,METAL FILM,1/10W,13.7K,1%,S0805  
S25000-10R0SMT RESISTOR,SMD,METAL FILM,1/10W,10.0OHMS,1%,S0805  
S25000-1501SMT RESISTOR,SMD,METAL FILM,1/10W,1.50K,1%,S0805  
S25000-2212SMT RESISTOR,SMD,METAL FILM,1/10W,22.1K,1%,S0805  
S25000-2002SMT RESISTOR,SMD,METAL FILM,1/10W,20.0K,1%,S0805  
S25000-1211SMT RESISTOR,SMD,METAL FILM,1/10W,1.21K,1%,S0805  
S25000-2211SMT RESISTOR,SMD,METAL FILM,1/10W,2.21K,1%,S0805  
S25000-3323SMT RESISTOR,SMD,METAL FILM,1/10W,332K,1%,S0805  
S25000-4752SMT RESISTOR,SMD,METAL FILM,1/10W,47.5K,1%,S0805  
S25000-3320SMT RESISTOR,SMD,METAL FILM,1/10W,332OHMS,1%,S0805  
S25000-4753SMT RESISTOR,SMD,METAL FILM,1/10W,475K,1%,S0805  
S25000-1000SMT RESISTOR,SMD,METAL FILM,1/10W,100OHMS,1%,S0805  
S25000-47R5SMT RESISTOR,SMD,METAL FILM,1/10W,47.5OHMS,1%,S0805  
S25000-3321SMT RESISTOR,SMD,METAL FILM,1/10W,3.32K,1%,S0805  
S25000-1821SMT RESISTOR,SMD,METAL FILM,1/10W,1.82K,1%,S0805  
S25000-6811SMT RESISTOR,SMD,METAL FILM,1/10W,6.81K,1%,S0805  
S25000-3922SMT RESISTOR,SMD,METAL FILM,1/10W,39.2K,1%,S0805  
S25000-1003SMT RESISTOR,SMD,METAL FILM,1/10W,100K,1%,S0805  
S25000-7501SMT RESISTOR,SMD,METAL FILM,1/10W,7.50K,1%,S0805  
S25000-2671SMT RESISTOR,SMD,METAL FILM,1/10W,2.67K,1%,S0805  
S25000-1822SMT RESISTOR,SMD,METAL FILM,1/10W,18.2K,1%,S0805  
S25001-1210SMT RESISTOR,SMD,121OHMS,1/4W,1206,1%,TR  
R20  
R22, R142, R144  
R23, R62, R86, R136, R158  
R24, R44, R91, R110, R121  
R25  
R27, R46, R75  
R30, R31, R168  
R35, R36, R106, R124  
R39  
R40, R45  
R41  
R54, R69, R77  
R55, R82, R125  
R58, R84  
R59  
1
N.E.  
N.B.  
2.75  
JI  
R60, R70, R73, R74, R78, R83, R113, R150  
R71, R76, R94, R97, R118  
R72, R80, R95, R96, R117  
3.50  
PRECISION TIG  
ADVANCED CONTROL  
R7  
R14  
R15  
3.30  
G4040-2  
R16  
R11  
R9  
R10  
R85, R119, R129  
R98, R99  
R100  
R114, R115  
R148  
R149, R159  
R156  
S1  
N.A. X1  
N.A. X2, X5, X6, X8, X11, X13  
N.A. X3  
N.A. X7  
N.A. X9, X12  
N.A. X10  
1
2
3
4
5
6
7
8
X1  
R12  
N.G.  
O
N
C2  
C4  
R26  
R13  
C9  
Q1  
R42  
J1  
S1  
C8  
R43  
R44  
S25000-3570SMT RESISTOR,SMD,METAL FILM,1/10W,357OHMS,1%,S0805  
S25000-2000SMT RESISTOR,SMD,METAL FILM,1/10W,200OHMS,1%,S0805  
S25000-6810SMT RESISTOR,SMD,METAL FILM,1/10W,681OHMS,1%,S0805  
Q2  
C10  
R45  
R37  
R38  
R52  
R39  
R40  
R56  
R41  
R57  
C18  
R51  
C19  
D5  
D6  
D2  
R53  
D4  
R68  
R54  
R55  
R66  
R67  
T10812-41  
TRIMMER,ST,1/2W,10K, 10%,LINEAR  
D3  
Q7  
TP2  
S25000-1652SMT RESISTOR,SMD,METAL FILM,1/10W,16.5K,1%,S0805  
S19869-8  
C30  
R69  
R70  
R71  
R72  
R86  
C26  
LED1  
R88  
SWITCH,DIP,SPST,8-CIRCUITS????SET_SWITCH_POSITIONS????  
IC,SMD,COMPARATOR,QUAD,2901D  
OP-AMP,SMD,QUAD, GEN-PURPOSE,224D  
IC,SMD,CMOS,CPLD,CY37192,160-TQFP(SS)  
IC,BIPOLAR,TIMER,SOIC-14  
C29  
R73  
R74  
D7  
R89  
R87  
S15128-11SMT  
S15128-4SMT  
S25070-12SMT  
S25067-1SMT  
S15018-6SMT  
S25057-2SMT  
TP3  
X3  
C24  
C34  
C35  
C36  
C37  
R100  
R101  
R102  
R103  
R104  
C32  
R91  
R94  
R95  
R96  
R97  
C47  
TP4  
R93  
LED2  
R105  
C50  
C40  
C42  
C44  
C49  
R114  
R115  
C46  
R113  
C48  
R108  
C38  
R120  
IC,SMD,CMOS,SW ITCH,ANALOG,QUAD, 4066BD(SS)  
POT,SMD,DIGITAL,10K,1-CHNL,SOIC-8  
R119  
C51  
C41  
R117  
R118  
R106  
R107  
C52  
R152  
R111  
R116  
R148  
R150  
R156  
Q4  
R135  
R136  
R137  
R138  
R144  
R145  
R146  
R147  
R126  
R127  
R128  
C56  
R153  
R154  
C57  
R157  
R158  
DZ3  
R125  
R130  
R142  
R149  
R159  
R129  
J2, J3MOUNTED  
ON BACK OF BOARD  
TP1  
C54  
C55  
R151  
R155  
.20  
0
HOT START  
ARC FORCE  
UNLESS OTHERWISE SPECIFIED:  
CAPACITANCE = MFD/VOLTS  
INDUCTANCE = HENRIES  
RESISTANCE = OHMS  
0
.20  
2.60  
5.50  
5.30  
N.F.  
NOTES:  
N.A. CAUTION: THIS DEVICE IS SUBJECT TO DAMAGE BY STATIC ELECTRICITY. SEE E2454  
BEFORE HANDLING.  
N.B. PROGRAM X3 WITH ITEM 2.  
N.D. DO NOT COAT WITH ENCAPSULATION MATERIAL.  
N.E. KEEP MOUNTING HOLES FREE OF ENCAPSULATION MATERIAL. (5 PLACES)  
N.F. KEEP TOP SURFACE OF TRIMMERS FREE OF ENCAPSULATION MATERIAL. (2 PLACES)  
N.G. KEEP TOP SURFACE OF DIP SWITCH FREE OF ENCAPSULATION MATERIAL.  
ALL COMPONENTS ANDMATERIALS USED IN THIS  
ASSEMB LYARE TO BE RoHS COMPLIANT PER E4253.  
THIS DOCUMEN T CON TAINS PROPRIETARY  
INFORMATION O WNED BY LINCOLN G LOBAL, INC. AND MA  
Y NOT BE DUPLICATED, COM  
MUNICATED  
PROPRIETARY & CONFIDENTIAL:  
TO O THER PARTIES OR USED FOR AN  
Y PURPOSE WITHOU  
T THE EXPRESS WRIT  
TEN PERMISSION OF LINCOLN GL OBAL, INC.  
UNLESS OTHERWISE SPECIFIED TOLERANCE  
DESIG  
N
INF OR MATIO  
N
REFERENCE:  
MANUF ACTURING TOLERANC PER E2056  
ON 2 PLA CE DE CIMA LS IS .02  
ON PLACE DEC IMALS IS .002  
.5 OF A DE GREE  
E
EQUIPMENT TYPE:  
PAGE _1__ OF ___  
1
INDUSTRIAL TIG  
±
FEI  
DRAWN BY:  
ENGI NEER:  
G4040-1 SUBJECT:  
3
±
DOCUMENT  
DOCUMENT  
NUMBER:  
ON AL L A NGLES IS  
±
ADVANCED CONTROL PC BOARD ASSEMBLY  
REVISION:  
MATER IAL T OLE RA NCE (" ") TO AG REE  
t
SCA LE:  
WITH PUB LIS HE D STAN DA RDS.  
MATERIAL  
APPROVAL  
3/16/0207  
DATE:  
PROJECT  
NUMBER:  
G4040-2  
CRM34409  
UF  
B
APPR OVED:  
-
1:1  
DISPOSITION:  
DO NOT SCAL E THI S DR AWING  
STRP  
NOTE: Lincoln Electric assumes no responsibility for liablilities resulting from board level troubleshooting. PC Board repairs will invalidate your factory warranty. Individual Printed Circuit Board Components are not available from Lincoln Electric. This information is pro-  
vided for reference only. Lincoln Electric discourages board level troubleshooting and repair since it may compromise the quality of the design and may result in danger to the Machine Operator or Technician. Improper PC board repairs could result in damage to the  
machine.  
®
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
G-28  
G-28  
ELECTRICAL DIAGRAMS  
SCHEMATIC - TIG OPTION P.C. BOARD - ABOVE CODE 11000 (G4760 PAGE 1)  
NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual.  
®
PRECISION TIG 275  
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G-29  
G-29  
ELECTRICAL DIAGRAMS  
SCHEMATIC - TIG OPTION P.C. BOARD - ABOVE CODE 11000 (G4760 PAGE 2)  
NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual.  
®
PRECISION TIG 275  
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G-30  
G-30  
ELECTRICAL DIAGRAMS  
SCHEMATIC - TIG OPTION P.C. BOARD - ABOVE CODE 11000 (G4760 PAGE 3)  
NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual.  
®
PRECISION TIG 275  
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G-31  
G-31  
ELECTRICAL DIAGRAMS  
PC BOARD ASSEMBLY - TIG OPTION P.C. BOARD - ABOVE CODE 11000 (G4761-1)  
1
6 7 1 4 - G  
ITEM  
QTY PART NUMB ER DESCRIPTION  
CHANGE DETAIL: RELEASED A.01 FROM "X"  
ENGINEERING CONTROLLED  
MANUFACTURER: No  
1
2
3
1
1
G4761-A  
S26859-1  
PC BOARD BLANK  
PSOC SOFTWARE (X14)  
SEALANT  
AS REQ E2861  
REFER TO ELECTRONIC COMPONENT DATABASE FOR SPECIFICATIONS ON ITEMS LISTED BELOW  
REFERENCES  
QTY PART NUMB ER DESCRIPTION  
C1, C2, C4, C5, C7, C10,  
C12, C14, C15, C17, C18,  
C19, C20, C26, C29, C30,  
C31, C32, C33, C34, C38,  
36  
S25020-3SMT  
CAPACITOR,SMD,CERAMIC,0.1MF,50V,10%,X7R,S0805  
C39, C43, C45, C49, C50,  
C51, C52, C53, C54, C55,  
C56, C57, C62, C63, C65  
C3, C8, C58, C64, C66  
C6  
C9, C27, C28, C46  
C11  
C35, C36, C37, C48  
C60  
D1  
5
1
4
1
4
1
1
S25020-2SMT  
S25020-5SMT  
S25020-27SMT  
S25020-9SMT  
S25020-24SMT  
S25020-14SMT  
S25040-2SMT  
CAPACITOR,SMD,CERAMIC,0.022MF,50V,10%,X7R,S0805  
CAPACITOR,SMD,CERAMIC,2700pF,50V,5%,X7R,S0805  
CAPACITOR,SMD,CER,0.1MF,50V,-20%+80%,Z5U,S0805  
CAPACITOR,SMD,CERAMIC,47pF,50V,5%,COG,S0805  
CAPACITOR,SMD,CERAMIC,1.0MF,25V,10% ,X7R,S1206  
CAPACITOR,SMD,CERAMIC,330pF,100V,5%,COG,S0805  
DIODE,SMD,1A,400V,DO-214BA/AC  
D2, D3, D4, D5, D6, D7,  
D8  
D9, D10, D11, D12, D13,  
D14  
7
6
S25049-4SMT  
S25040-5SMT  
DIODE,SMD,SCHOTTKY,DUAL,0.200A,30V,SOT-23  
DIODE,SMD,DUAL,0.200A,70V,UFR  
DZ1, DZ5  
DZ3  
DZ4  
J1  
J2, J3  
2
1
1
1
2
1
1
2
1
5
1
S25046-1SMT  
S25046-4SMT  
S25046-3SMT  
S24020-12  
S21135-10  
S24020-2  
ZENER DIODE,SMD,0.5W,5.1V, 5%,SOD123  
ZENER DIODE,SMD,0.5W,12V,5%,SOD-123  
ZENER DIODE,SMD,0.5W,18V, 5%,SOD123  
CONNECTOR,MOLEX,MINI,PCB,12-PIN,TIN  
CONNECTOR,MOLEX,MINI,BLIND,F,10-PIN  
CONNECTOR,MOLEX,MINI,PCB,2-PIN,TIN  
CONNECTOR,MOLEX,MINI,PCB,4-PIN,TIN  
LED,SMD,GREEN,CLEAR,S1206  
N.D.  
J20  
{
J21  
S24020-4  
LED1, LED2  
S25080-2SMT  
S15000-34SMT  
S25050-1SMT  
S25051-4SMT  
OCI1  
IC,SMD,OPTOCOUPLER,HMA124  
TRANSISTOR,SMD,NPN,0.5A,40V,SOT-23,MMBT4401LT1  
TRANSISTOR,SMD,NMF,SOT-23,0.115A,60V,7002LT1(SS)  
Q2, Q3, Q6, Q7, Q8  
Q5  
R1, R2, R3, R4, R5, R8,  
R25  
7
S25000-2211SMT RESISTOR,SMD,METAL FILM,1/10W,2.21K,1%,S0805  
S25000-1002SMT RESISTOR,SMD,METAL FILM,1/10W,10.0K,1%,S0805  
R6, R10, R13, R14, R16,  
R17, R18, R21, R26, R28,  
R29, R32, R33, R48, R52,  
R58, R59, R61, R65, R72,  
R82, R84, R85, R89, R92,  
R101, R102, R103, R104,  
R116, R120, R123, R128,  
R130, R135, R137, R138,  
R139, R140, R141, R143,  
R151, R152, R153, R154,  
R155, R157,  
48  
N.C.  
2.75  
1
R7  
1
3
S25058-1SMT  
TRIMMER,SMD,ST,1/4W,10K,10%,LINEAR  
N.E.  
R9, R148, R175  
R11, R35, R36, R106,  
R111, R124  
R12, R45, R169, R170,  
R171  
S25000-6810SMT RESISTOR,SMD,METAL FILM,1/10W,681OHMS,1%,S0805  
6
5
S25000-3320SMT RESISTOR,SMD,METAL FILM,1/10W,332OHMS,1%,S0805  
J1,J20,J21  
3.50  
PRECISION TIG  
ADVANCED CONTROL  
R7  
S25000-1000SMT RESISTOR,SMD,METAL FILM,1/10W,100OHMS,1%,S0805  
3.30  
R14  
R15  
R16  
G4761-1  
X
R15  
R20  
1
1
3
3
4
2
3
S25000-1372SMT RESISTOR,SMD,METAL FILM,1/10W,13.7K,1%,S0805  
S25000-1501SMT RESISTOR,SMD,METAL FILM,1/10W,1.50K,1%,S0805  
S25000-2212SMT RESISTOR,SMD,METAL FILM,1/10W,22.1K,1%,S0805  
S25000-2002SMT RESISTOR,SMD,METAL FILM,1/10W,20.0K,1%,S0805  
S25000-1211SMT RESISTOR,SMD,METAL FILM,1/10W,1.21K,1%,S0805  
S25000-3323SMT RESISTOR,SMD,METAL FILM,1/10W,332K,1%,S0805  
S25000-4752SMT RESISTOR,SMD,METAL FILM,1/10W,47.5K,1%,S0805  
Q8  
1
2
3
4
5
6
7
8
X
XX  
XX  
N.G.  
X
O
N
XX  
J1  
J21  
J20  
S1  
R22, R142, R144  
R23, R136, R158  
R24, R44, R110, R178  
R27, R46  
R30, R31, R70  
R34, R37, R38, R50, R67,  
R75, R76, R127, R131,  
R132, R133, R181  
R39, R60, R66, R87,  
R105, R126, R166, R167,  
R177  
N.H.  
C10  
D11  
R85  
C46  
R177  
R176  
XX  
C9  
C28  
XX  
X
R123  
R107  
DZ4  
D10  
D5  
N.J.  
R24  
C63  
R60  
Q2  
D3  
D7  
C1  
Q7  
R66  
R67  
D4  
X
X
X
X
X
X
R87  
TP2  
R39  
X
X
X
C30  
C29  
LED1  
R88  
D2  
R64  
R12  
NOTES:  
TP5  
12  
S25000-5110SMT RESISTOR,SMD,METAL FILM,1/10W,511OHMS,1%,S0805  
C38  
C53  
R121  
N.A. CAUTION: THIS DEVICE IS SUBJECT TO DAMAGE BY STATIC ELECTRICITY. SEE E2454  
BEFORE HANDLING.  
C35  
C34  
C50  
C36  
C37  
LED2  
C19  
N.J.  
D12  
N.B. PROGRAM X14 WITH ITEM 2 AND LABEL X14 WITH PART NUMBER OF ITEM 2.  
N.C. APPLY ITEM 3 TO COMPONENT SIDE OF BOARD AS SHOWN.  
N.D. DO NOT COAT WITH ENCAPSULATION MATERIAL.  
N.E. KEEP MOUNTING HOLES FREE OF ENCAPSULATION MATERIAL. (5 PLACES)  
N.F. KEEP TOP SURFACE OF TRIMMERS FREE OF ENCAPSULATION MATERIAL. (2 PLACES)  
N.G. KEEP TOP SURFACE OF DIP SWITCH FREE OF ENCAPSULATION MATERIAL.  
N.H. APPLY ITEM 3 AROUND BASE OF J2 & J3 ON BACK SIDE OF BOARD. LIMIT HEIGHT TO  
.125 +0/-.0625 INCHES.  
D13  
Q6  
TP4  
9
5
S25000-4751SMT RESISTOR,SMD,METAL FILM,1/10W,4.75K,1%,S0805  
S25000-47R5SMT RESISTOR,SMD,METAL FILM,1/10W,47.5OHMS,1%,S0805  
R105  
C49  
R102  
R104  
R103  
C51  
X
R99  
C52  
R152  
C7  
D14  
C56  
R120  
C55  
R6  
R117  
R118  
R116  
R144  
R41, R172, R176, R182,  
R183  
Q3  
D8  
R158  
R156  
R89  
R148  
R150  
D9  
R157  
Q5  
R145  
R146  
R119  
R155  
R42, R43, R47, R64, R68,  
R71, R83, R88, R90, R91,  
R107, R109, R112, R121,  
R145, R146, R147, R174,  
R179  
R49, R51, R77, R134,  
R180  
R54, R69  
R55, R125  
R57, R97  
R73, R74, R150  
R86  
R94, R118  
R95, R117  
R96  
R98, R99  
R108, R122  
R114, R115  
R119, R129  
R149, R159  
R156  
C32  
R149  
R159  
C57  
R153  
C54  
J2, J3MOUNTED  
ON BACK OF BOARD  
TP1  
D6  
R151  
R154  
.20  
0
HOT START  
ARC FORCE  
19  
5
S25000-1001SMT RESISTOR,SMD,METAL FILM,1/10W,1.00K,1%,S0805  
S25000-4750SMT RESISTOR,SMD,METAL FILM,1/10W,475OHMS,1%,S0805  
N.J. APPLY ITEM 3 TO CONNECTOR’S PLASTIC MOUNTING PINS.  
0
.20  
2.60  
5.30  
5.50  
N.F.  
2
N.B.  
2
2
2
3
1
2
2
1
2
2
2
2
2
1
1
1
3
1
2
2
1
1
2
S25000-3321SMT RESISTOR,SMD,METAL FILM,1/10W,3.32K,1%,S0805  
S25000-1821SMT RESISTOR,SMD,METAL FILM,1/10W,1.82K,1%,S0805  
S25000-10R0SMT RESISTOR,SMD,METAL FILM,1/10W,10.0OHMS,1%,S0805  
S25000-1003SMT RESISTOR,SMD,METAL FILM,1/10W,100K,1%,S0805  
S25000-3162SMT RESISTOR,SMD,METAL FILM,1/10W,31.6K,1%,S0805  
S25000-7501SMT RESISTOR,SMD,METAL FILM,1/10W,7.50K,1%,S0805  
S25000-2671SMT RESISTOR,SMD,METAL FILM,1/10W,2.67K,1%,S0805  
S25084-2SMT  
THERMISTOR,SMD,PTC,0.35./1.4OHMS,2.0A  
S25001-1210SMT RESISTOR,SMD,121OHMS,1/4W,1206,1%,TR  
S25000-9091SMT RESISTOR,SMD,METAL FILM,1/10W,9.09K,1%,S0805  
S25000-2000SMT RESISTOR,SMD,METAL FILM,1/10W,200OHMS,1%,S0805  
S25000-1822SMT RESISTOR,SMD,METAL FILM,1/10W,18.2K,1%,S0805  
REVISION CONTROL  
T10812-41  
TRIMMER,ST,1/2W ,10K, 10%,LINEAR  
G4761-1A0  
S25000-1652SMT RESISTOR,SMD,METAL FILM,1/10W,16.5K,1%,S0805  
S19869-8  
S1  
X1  
SWITCH,DIP,SPST,8-CIRCUITS????SET_SWITCH_POSITIONS????  
IC,SMD,COMPARATOR,QUAD,2901D  
PART NO. IDENTIFICATION  
CODE  
S15128-11SMT  
S15128-28SMT  
S25067-1SMT  
S15128-4SMT  
S15018-6SMT  
S25057-2SMT  
S25073-12SMT  
S25065-3SMT  
X2, X6, X11  
X7  
X8, X13  
X9, X12  
IC,OP-AMP,SMT,QUAD,HIGH-PERF,33074ADT  
IC,BIPOLAR,TIMER,SOIC-14  
OP-AMP,SMD,QUAD, GEN-PURPOSE,224D  
IC,SMD,CMOS,SWITCH,ANALOG,QUAD, 4066BD(SS)  
POT,SMD,DIGITAL,10K,1-CHNL,SOIC-8  
TEST PER E4298-AC  
COAT WITH E1844 AND E3668  
SCHEMATIC REFERENCE: G4760-1A0  
N.A.  
X10  
MAK E DETAIL  
MANUFACTURE PER E1911  
BUY BLANK COMPLETE  
(6 BOARDS PER PANEL)  
X14  
IC,SMD,CMOS,PSOC,8-BIT,CY8C27643,TFN49(SS)  
IC,SMD,CMOS,INVERTER,SCHMITT,HEX,VHC14(SS)  
{
X15, X16  
UNLESS OTHERWISE SPECIFIED:  
CAPACITANCE = MFD/VOLTS  
INDUCTANCE = HENRIES  
RESISTANCE = OHMS  
4 LAYER BOARD BLANK PANEL  
SEE ELECTRONIC FILE FOR ADDITIONAL INFORMATION.  
ALL COMPONENTS AND MATERIALS USED IN THIS  
ASSEMBLY ARE TO BE RoHS COMPLIANT PER E4253  
THIS DOCUMEN T CON TAINS PROPRIETARY  
INFORMATION O WNED BY LINCOLN G LOBAL, INC. AND MA  
Y NOT BE DUPLICATED, COM  
TEN PERMISSION OF LINCOLN GL OBAL, INC.  
MUNICATED  
PROPRIETARY & CONFIDENTIAL:  
TO O THER PARTIES OR USED FOR AN  
Y PURPOSE WITHOU  
T THE EXPRESS WRIT  
UNLESS OTHERWISE SPECIFIED TOLERANCE  
DESIG  
N
INF OR MATIO  
N
REFERENCE:  
G4040  
SCA LE:  
MANUF ACTURING TOLERANC PER E2056  
ON 2 PLA CE DE CIMA LS IS .02  
ON PLACE DEC IMALS IS .002  
.5 OF A DE GREE  
E
EQUIPMENT TYPE:  
SUBJECT:  
PAGE _1__ OF ___  
1
INDUSTRIAL TIG  
±
Jbarto  
T Nguyen  
-
DRAWN BY:  
ENGI NEER:  
3
±
DOCUMENT  
DOCUMENT  
NUMBER:  
ON AL L A NGLES IS  
±
ADVANCED CONTROL PC BOARD ASSEMBLY  
REVISION:  
MATER IAL T OLE RA NCE (" ") TO AG REE  
t
WITH PUB LIS HE D STAN DA RDS.  
MATERIAL  
APPROVAL  
DATE:  
PROJECT  
NUMBER:  
G4761-1  
CRM38259  
NA  
A
APPR OVED:  
3/5/2007  
1:1  
DISPOSITION:  
DO NOT SCAL E THI S DR AWING  
STRP  
NOTE: Lincoln Electric assumes no responsibility for liablilities resulting from board level troubleshooting. PC Board repairs will invalidate your factory warranty. Individual Printed Circuit Board Components are not available from Lincoln Electric. This information is pro-  
vided for reference only. Lincoln Electric discourages board level troubleshooting and repair since it may compromise the quality of the design and may result in danger to the Machine Operator or Technician. Improper PC board repairs could result in damage to the  
machine.  
®
PRECISION TIG 275  
Download from Www.Somanuals.com. All Manuals Search And Download.  
SVM ERROR REPORTING FORM  
We need to know if there are errors in our manuals. We also value any suggestions as to  
additional tests or procedures that would make this SVM a better tool for you.  
If you discover new or different “Problems or Symptoms” that are not covered in the three col-  
umn troubleshooting chart, please share this information with us. Please include the  
machine’s code number and how the problem was resolved.  
Thank You,  
Technical Services Group  
Lincoln Electric Co.  
22801 ST. Clair Ave.  
Cleveland, Ohio 44117-1199  
FAX 216-481-2309  
SVM Number ___________________________  
Page Number if necessary__________________  
Your Company__________________________  
Your Name_____________________________  
Please give detailed description below:  
___________________________________________________________________________  
___________________________________________________________________________  
___________________________________________________________________________  
___________________________________________________________________________  
___________________________________________________________________________  
___________________________________________________________________________  
___________________________________________________________________________  
___________________________________________________________________________  
___________________________________________________________________________  
___________________________________________________________________________  
___________________________________________________________________________  
___________________________________________________________________________  
___________________________________________________________________________  
SD287 01/99  
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