38AKS013-024
Air-Cooled Condensing Units
50/60 Hz
Installation, Start-Up and
Service Instructions
Only trained, qualified installers and service mechanics
CONTENTS
should install, start-up, and service this equipment (Fig. 1).
Page
Untrained personnel can perform basic maintenance func-
tions such as cleaning coils. All other operations should be
performed by trained service personnel.
When working on the equipment, observe precautions in
the literature and on tags, stickers, and labels attached to the
equipment.
Follow all safety codes. Wear safety glasses and work gloves.
Keep quenching cloth and fire extinguisher nearby when braz-
ing. Use care in handling, rigging, and setting bulky equip-
ment.
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . 1
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12
Step 1 — Complete Pre-Installation
Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Step 2 — Rig and Mount the Unit . . . . . . . . . . . . . 8
Step 3 — Complete Refrigerant Piping
Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Step 4 — Install Accessories . . . . . . . . . . . . . . . . 10
Step 5 — Complete Electrical
Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
PRE-START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
System Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Leak Test and Dehydration . . . . . . . . . . . . . . . . . . 12
Turn On Crankcase Heater . . . . . . . . . . . . . . . . . . . 12
Preliminary Charge . . . . . . . . . . . . . . . . . . . . . . . . . . 12
ELECTRIC SHOCK HAZARD
Separate power sources (main and control
power circuits) are used for these units. Be
sure both main and control power circuits are
disconnected before servicing.
START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-16
Preliminary Checks . . . . . . . . . . . . . . . . . . . . . . . . . 13
Preliminary Oil Charge . . . . . . . . . . . . . . . . . . . . . . 13
Start Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Adjust Refrigerant Charge . . . . . . . . . . . . . . . . . . . 13
Check Compressor Oil Level . . . . . . . . . . . . . . . . 13
Final Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
INSTALLATION
Step 1 — Complete Pre-Installation Checks
OPERATING SEQUENCE . . . . . . . . . . . . . . . . . . . . 17
Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Fan Cycling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Winter Start Control . . . . . . . . . . . . . . . . . . . . . . . . . 17
UNCRATE UNIT — Remove unit packaging except for the
top skid assembly, which should be left in place until after
the unit is rigged into its final location.
INSPECT SHIPMENT — File claim with shipping com-
pany if shipment is damaged or incomplete.
SERVICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-19
Capacity Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Head Pressure Control . . . . . . . . . . . . . . . . . . . . . . 17
Time Guardா II Circuit . . . . . . . . . . . . . . . . . . . . . . . 17
Winter Start Control . . . . . . . . . . . . . . . . . . . . . . . . . 18
Crankcase Heater . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Compressor Protection . . . . . . . . . . . . . . . . . . . . . . 18
High-Pressure Switches . . . . . . . . . . . . . . . . . . . . . 18
Low-Pressure Switches . . . . . . . . . . . . . . . . . . . . . 18
Outdoor Fans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Cleaning Coils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
CONSIDER SYSTEM REQUIREMENTS
• Consult local building codes and National Electrical Code
(NEC, U.S.A.) for special installation requirements.
• Allow sufficient space for airflow clearance, wiring,
refrigerant piping, and servicing unit. See Fig. 1. See
Fig. 2 for unit component locations.
• Locate unit so that outdoor coil (condenser) airflow is un-
restricted on all sides and above.
• Unit may be mounted on a level pad directly on the base
channels or mounted on raised pads at support points. See
Tables 1A-1D for unit operating weights. See
Table 2 for weight distribution based on recommended sup-
port points.
NOTE: If vibration isolators are required for a particular
installation, use the data in Table 2 to make the proper
selection.
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . 20,21
START-UP CHECKLIST . . . . . . . . . . . . . . . . CL-1,CL-2
SAFETY CONSIDERATIONS
Installing, starting up, and servicing air-conditioning equip-
ment can be hazardous due to system pressures, electrical
components, and equipment location (roofs, elevated struc-
tures, etc.).
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 PC 111 Catalog No. 563-701 Printed in U.S.A. Form 38AKS-3SI Pg 1 9-98 Replaces: 38AKS-2SI
Tab 3a 2a
4
NOTE: Service areas — Allow 3 ft (914 mm) on both sides and 2 ft (610 mm)
on both ends of unit for servicing.
Fig. 1 — Dimensions
Table 1A — Physical Data (English, 60 Hz)
UNIT 38AKS
013
014
016
024
OPERATING WEIGHT (lb)
With Aluminum-Fin Coil
With Copper-Fin Coil
732
825
779
919
789
929
900
1040
REFRIGERANT*
Shipping Charge (lb)
Operating Charge, Typical (lb)†
R-22
2.1
22
3.1
23
3.1
23
3.1
28
COMPRESSOR
Model
Reciprocating, Semi-Hermetic
06DD824
6
06DD328
6
06DD537
06EA250
4
No. Cylinders
Speed (rpm)
Capacity Steps (%)
Accessory
6
1750
33**,66,100
66,100
33**,66,100
66,100
33**,66,100
66,100
—
50,100
Standard
Crankcase Heater Watts
Unloader Setting (psig)
Load
125
70 ± 1
60 ± 2
Unload
OIL CHARGE (pt)
10
10
10
15.5
CONDENSER FANS
Quantity...Diameter (in.)
Nominal Hp
Axial Flow, Direct Drive
2...26
1
⁄
2
Nominal Airflow (cfm, total)
Speed (rpm)
11,000
1,075
1,460
Watts (total)
CONDENSER COIL
Rows...Fins/in.
Total Face Area (sq ft)
Storage Capacity (lb)††
Copper Tubes, Aluminum Fins
2...15
29.2
27.2
3...15
29.2
40.3
3...15
29.2
39.8
3...15
29.2
39.8
CONTROLS
Pressurestat (psig)
High Pressure
Cutout
395 ± 10
295 ± 20
Cut-in
Low Pressure
Cutout
Cut-in
27 ± 4
67 + 7
FAN CYCLING CONTROLS
No 2 Fan:
Close (psig)
255 ± 10
160 ± 10
Open (psig)
PRESSURE RELIEF
Location
Temperature (F)
Fusible Plug
Compressor
200
Compressor
200
Compressor
200
Liquid Line
210
PIPING CONNECTIONS (in. ODM)
Suction
11⁄8
13⁄8
13⁄8
15⁄8
5
3
Liquid
Hot Gas Stub
⁄
⁄
8
8
*Unit is factory supplied with holding charge only.
†With 25 ft of interconnecting piping. Operating charge is approximate for maximum system capacity.
**Indicates capacity step (%) with electric unloader accessory.
††Storage capacity is measured at liquid saturated temperatures of 125 F for 38AKS013, 123 F for
38AKS014, and 130 F for 38AKS016 and 024.
4
Table 1B — Physical Data (SI, 60 Hz)
UNIT 38AKS
013
014
016
024
OPERATING WEIGHT (kg)
With Aluminum-Fin Coil
With Copper-Fin Coil
332
374
353
417
358
421
408
472
REFRIGERANT*
Shipping Charge (kg)
Operating Charge, Typical (kg)†
R-22
0.95
10.0
1.40
10.4
1.40
10.4
1.40
12.7
COMPRESSOR
Model
Reciprocating, Semi-Hermetic
06DD824
6
06DD328
6
06DD537
06EA250
4
No. Cylinders
Speed (r/s)
6
29.2
Capacity Steps
Accessory
Standard
33**,66,100
66,100
33**,66,100
66,100
33**,66,100
66,100
—
50,100
Crankcase Heater Watts
Unloader Setting (kPa)
Load
125
483 ± 6.9
414 ± 13.8
Unload
OIL CHARGE (L)
4.73
4.73
4.73
7.33
CONDENSER FANS
Quantity...Diameter (mm)
Nominal kW
Axial Flow, Direct Drive
2...660
0.37
Nominal Airflow (L/s, total)
Speed (r/s)
5566
17.9
1460
Watts (total)
CONDENSER COIL
Rows...Fins/m
Total Face Area (sq m)
Storage Capacity (kg)††
Copper Tubes, Aluminum Fins
2...590
2.71
12.3
3...590
2.71
3...590
2.71
3...590
2.71
18.1
18.3
18.1
CONTROLS
Pressurestat (kPa)
High Pressure
Cutout
2724 ± 69
2034 ± 138
Cut-in
Low Pressure
Cutout
Cut-in
186 ± 28
462 + 48
FAN CYCLING CONTROLS
No 2 Fan:
Close (kPa)
1758 ± 69
1103 ± 69
Open (kPa)
PRESSURE RELIEF
Location
Temperature (C)
Fusible Plug
Compressor
93.3
Compressor
93.3
Compressor
93.3
Liquid Line
98.9
PIPING CONNECTIONS (in. ODM)
Suction
11⁄8
13⁄8
13⁄8
15⁄8
5
3
Liquid
Hot Gas Stub
⁄
⁄
8
8
*Unit is factory supplied with holding charge only.
†With 7.6 m of interconnecting piping. Operating charge is approximate for maximum system capacity.
**Indicates capacity step (%) with electric unloader accessory.
††Storage capacity is measured at liquid saturated temperatures of 51.7 C for 38AKS013, 50.6 C for
38AKS014, and 54.4 C for 38AKS016 and 024.
5
Table 1C — Physical Data (English, 50 Hz)
UNIT 38AKS
013
014
016
024
OPERATING WEIGHT (lb)
With Aluminum-Fin Coil
With Copper-Fin Coil
732
825
779
919
789
929
900
1040
REFRIGERANT*
Shipping Charge (lb)
Operating Charge, Typical (lb)†
R-22
2.1
22
3.1
23
3.1
23
3.1
28
COMPRESSOR
Model
Reciprocating, Semi-Hermetic
06DD824
6
06DD328
6
06DD537
06EA250
4
No. Cylinders
Speed (rpm)
Capacity Steps
Accessory
6
1450
33**,66,100
66,100
33**,66,100
66,100
33**,66,100
66,100
—
50,100
Standard
Crankcase Heater Watts
Unloader Setting (psig)
Load
125
70 ± 1
60 ± 2
Unload
OIL CHARGE (pt)
10
10
10
15.5
CONDENSER FANS
Quantity...Diameter (in.)
Nominal Hp
Axial Flow, Direct Drive
2...26
1
⁄
2
Nominal Airflow (cfm, total)
Speed (rpm)
9210
900
Watts (total)
1050
CONDENSER COIL
Rows...Fins/in.
Total Face Area (sq ft)
Storage Capacity (lb)††
Copper Tubes, Aluminum Fins
2...15
29.2
27.2
3...15
29.2
40.3
3...15
29.2
39.8
3...15
29.2
39.8
CONTROLS
Pressurestat (psig)
High Pressure
Cutout
395 ± 10
295 ± 20
Cut-in
Low Pressure
Cutout
Cut-in
27 ± 4
67 + 7
FAN CYCLING CONTROLS
No 2 Fan:
Close (psig)
255 ± 10
160 ± 10
Open (psig)
PRESSURE RELIEF
Location
Temperature (F)
Fusible Plug
Compressor
200
Compressor
200
Compressor
200
Liquid Line
210
PIPING CONNECTIONS (in. ODM)
Suction
11⁄8
13⁄8
13⁄8
15⁄8
5
3
Liquid
Hot Gas Stub
⁄
⁄
8
8
*Unit is factory supplied with holding charge only.
†With 25 ft of interconnecting piping. Operating charge is approximate for maximum system capacity.
**Indicates capacity step (%) with electric unloader accessory.
††Storage capacity is measured at liquid saturated temperatures of 125 F for 38AKS013, 123 F for
38AKS014, and 130 F for 38AKS016 and 024.
6
Table 1D — Physical Data (SI, 50 Hz)
UNIT 38AKS
013
014
016
024
OPERATING WEIGHT (kg)
With Aluminum-Fin Coil
With Copper-Fin Coil
332
374
353
417
358
421
408
472
REFRIGERANT*
Shipping Charge (kg)
Operating Charge, Typical (kg)†
R-22
0.95
10.0
1.40
10.4
1.40
10.4
1.40
12.7
COMPRESSOR
Model
Reciprocating, Semi-Hermetic
06DD824
6
06DD328
6
06DD537
06EA250
4
No. Cylinders
Speed (r/s)
6
24.2
Capacity Steps
Accessory
Standard
33**,66,100
66,100
33**,66,100
66,100
33**,66,100
66,100
—
50,100
Crankcase Heater Watts
Unloader Setting (kPa)
Load
125
483 ± 6.9
414 ± 13.8
Unload
OIL CHARGE (L)
4.73
4.73
4.73
7.33
CONDENSER FANS
Quantity...Diameter (mm)
Nominal kW
Axial Flow, Direct Drive
2...660
0.37
Nominal Airflow (L/s, total)
Speed (r/s)
4660
15.0
1050
Watts (total)
CONDENSER COIL
Rows...Fins/m
Total Face Area (sq m)
Storage Capacity (kg)††
Copper Tubes, Aluminum Fins
2...590
2.71
12.3
3...590
2.71
3...590
2.71
3...590
2.71
18.1
18.3
18.1
CONTROLS
Pressurestat (kPa)
High Pressure
Cutout
2724 ± 69
2034 ± 138
Cut-in
Low Pressure
Cutout
Cut-in
186 ± 28
462 + 48
FAN CYCLING CONTROLS
No 2 Fan:
Close (kPa)
1758 ± 69
1103 ± 69
Open (kPa)
PRESSURE RELIEF
Location
Temperature (C)
Fusible Plug
Compressor
93.3
Compressor
93.3
Compressor
93.3
Liquid Line
98.9
PIPING CONNECTIONS (in. ODM)
Suction
11⁄8
13⁄8
13⁄8
15⁄8
5
3
Liquid
Hot Gas Stub
⁄
⁄
8
8
*Unit is factory supplied with holding charge only.
†With 7.6 m of interconnecting piping. Operating charge is approximate for maximum system capacity.
**Indicates capacity step (%) with electric unloader accessory.
††Storage capacity is measured at liquid saturated temperatures of 51.7 C for 38AKS013, 50.6 C for
38AKS014, and 54.4 C for 38AKS016 and 024.
7
Table 2 — Weight Distribution
WEIGHT
Support Point
UNIT
38AKS
Total
Operating
A
B
C
D
E
F
lb
732 332
825 374 119 54 116 53 115 52 157 71 159 72 159 72
779 353 95 43 94 43 94 43 164 74 166 75 166 75
919 417 131 59 129 59 128 58 176 80 177 80 178 81
789 358 95 43 95 43 96 44 167 76 168 76 168 76
kg
lb
kg
lb
kg
lb
kg
lb
kg
lb
kg
lb
kg
013
94 43
93 42
93 42 149 68 151 68 152 69
013C
014
014C
016
016C
024
929 421 131 59 130 59 130 59 178 81 180 82 180 82
900 408 119 54 114 52 113 51 179 81 185 84 190 86
1040 472 155 70 150 68 146 66 191 87 196 89 202 92
024C
Step 2 — Rig and Mount the Unit
Step
Connections
3
—
Complete Refrigerant Piping
IMPORTANT: A refrigerant receiver is not provided with
the unit. Do not install a receiver.
Be sure unit panels are securely in place prior to
rigging.
SIZE REFRIGERANT LINES — Consider the length of pip-
ing required between outdoor unit and indoor unit (evapo-
rator), the amount of liquid lift, and compressor oil return.
See Tables 3-5B and also refer to Part 3 of Carrier System
Design Manual and E20-II software for design details and
line sizing. Refer to indoor unit installation instructions for
additional information.
RIGGING — These units are designed for overhead rigging
only. For this purpose, the transverse base channels extend
beyond the sides of the unit, with holes provided in the end
plates to attach cables or hooks. Rig with top skid packaging
assembly in place to prevent unit damage by the rigging cable.
As further protection for the coil faces, plywood sheets can
be placed against the sides of the unit, behind the cables.
Run the cables to a central suspension point so that the angle
from the horizontal is not less than 45 degrees. Raise and set
the unit down carefully.
NOTE: Use the piping data in Tables 3-5B as a general guide
only. For more precise calculations, refer to Carrier System
Design manual or E20-II software.
Condensing units with multiple-step unloading may
require double suction risers to assure proper oil return at
minimum load operating condition. See Tables 4A-5B and
Fig. 4. Reduction of evaporator coil surface should be ana-
lyzed to provide sufficient refrigerant velocity to return oil
to the compressor. Liquid line solenoid valves may be used
in certain situations to accomplish this. Hot gas bypass, if
used, should be introduced before the evaporator.
If it is necessary to roll the unit into position, mount
the unit on longitudinal rails, using a minimum of 3 rollers.
Apply force to the rails, not the unit. If the unit is to be skid-
ded into position, place it on a large pad and drag it by the
pad. Do not apply any force to the unit.
Raise from above to lift unit from the rails or pad when
unit is in final position.
COMPRESSOR MOUNTING — As shipped, the compres-
sor is held tightly in place by self-locking bolts. Before start-
ing unit, loosen self-locking bolts until the snubber washer
can be moved sideways with finger pressure. Do not
remove shipping bolts. See Fig. 3.
Note that refrigerant suction piping should be insulated.
Table 3 — Liquid Line Data
MAXIMUM
ALLOWABLE
LIQUID LINE
LIQUID LIFT
ft (m)
UNIT
Maximum Maximum Filter Drier
38AKS
Allowable Allowable
and
60 Hz
50 Hz Pressure
Temp.
Loss
F (C)
Sight Glass
Flare Conn.*
in. (mm)
Drop
psig (kPa)
013
014
016
52 (15.8)
67 (20.4)
82 (25.0
5
7 (48.3)
2 (1.1)
⁄8
(15.88)
024 87 (26.5) 86 (26)
*Inlet and outlet.
NOTE: Data shown is for units operating at 45 F (7.2 C) saturated
suction and 95 F (35 C) entering air.
Fig. 3 — Compressor Mounting
8
Table 4A — Refrigerant Piping Sizes — 60 Hz Units
Table 5A — Refrigerant Piping Sizes — 50 Hz Units
LENGTH OF INTERCONNECTING PIPING, FT (M)
LENGTH OF INTERCONNECTING PIPING, FT (M)
0-15
(0-4.5)
15-25
25-50
50-75
75-100
(23-30)
0-15
(0-4.5)
15-25
25-50
50-75
75-100
(23-30)
COND
UNIT
38AKS
UNIT
38AKS
(4.5-7.5)
(7.5-15)
(15-23)
(4.5-7.5)
(7.5-15)
(15-23)
Line Size (in. OD)
Line Size (in. OD)
L
S
S
S
S
S
S
S
S
S
S
1
1
1
5
013
014
016
024
⁄
⁄
⁄
⁄
2
2
2
8
11⁄8
11⁄8
13⁄8
15⁄8
11⁄8
13⁄8
13⁄8
15⁄8
13⁄8
13⁄8
15⁄8
15⁄8
13⁄8
15⁄8
15⁄8
21⁄8
*
*
*
013
014
016
024
11⁄8
11⁄8
13⁄8
13⁄8
11⁄8
13⁄8
13⁄8
13⁄8
13⁄8
13⁄8
15⁄8
15⁄8
13⁄8
15⁄8
15⁄8
15⁄8
13⁄8
15⁄8
15⁄8
15⁄8
*
*
*
15⁄8
15⁄8
21⁄8
*
*
*
*
21⁄8
*Requires a double suction riser if 2 unloaders are used and the evapo-
rator is below the condensing unit. See Table 5B and Fig. 4 for more
information.
LEGEND
L
S
—
—
Liquid
Suction
NOTES:
Close-coupled.
1. Pipe sizes are based on 2 F (1.1 C) max loss for liquid lines and
1.5 F (0.8 C) max loss for suction lines, selected at maximum length
for each interval and for matched systems at nominal rating con-
ditions, nominal airflow.
*Requires a double suction riser if 2 unloaders are used and the
evaporator is below the condensing unit. See Table 4B and Fig. 4
for more information.
2. Pipe sizes are based on an equivalent length equal to the maxi-
mum length of interconnecting piping plus 50% for fittings. A more
accurate estimate may result in smaller sizes.
3. See Table 4A for line size conversion to mm.
NOTES:
1. Pipe sizes are based on a 2 F (1.1 C) loss for liquid lines and a
1.5 F (0.8 C) loss for suction lines.
2. Pipe sizes are based on an equivalent length equal to the maxi-
mum length of interconnecting piping plus 50% for fittings. A more
accurate estimate may result in smaller sizes.
3. Line size conversion to mm:
Table 5B — Refrigerant Piping Sizes,
Double Suction Risers — 50 Hz Units
in.
mm
1
5
7
⁄
⁄
⁄
2
8
8
12.7
15.9
22.2
28.6
34.9
41.3
54.0
LENGTH OF INTERCONNECTING PIPING FT (M)
11⁄8
13⁄8
15⁄8
21⁄8
25-50
(7.5-15)
50-75
(15-23)
75-100
(23-30)
COND
UNIT
38AKS
Line Size (in. OD)
A
B
C
A
B
C
A
B
C
013
014
016
—
—
—
—
—
—
—
—
—
11⁄8
11⁄8
11⁄8
13⁄8
13⁄8
13⁄8
15⁄8
15⁄8
15⁄8
11⁄8
11⁄8
13⁄8
13⁄8
15⁄8
15⁄8
Table 4B — Refrigerant Piping Sizes,
Double Suction Risers — 60 Hz Units
11⁄8
13⁄8
15⁄8
NOTES:
1. See Fig. 4 for ‘‘A,’’ ‘‘B,’’ and ‘‘C’’ dimensions.
2. Double suction risers are not required for unit size 024.
3. See Table 4A for line size conversion to mm.
LENGTH OF INTERCONNECTING PIPING, FT (M)
50-75
75-100
(23-30)
UNIT
(15-23)
38AKS
Line Size (in. OD)
A
B
C
A
B
C
013
014
016
—
11⁄8
—
—
13⁄8
—
—
15⁄8
—
11⁄8
11⁄8
13⁄8
13⁄8
13⁄8
15⁄8
15⁄8
15⁄8
21⁄8
NOTES:
1. See Fig. 4 for ‘‘A,’’ ‘‘B,’’ and ‘‘C’’ dimensions.
2. No double suction risers are needed for unit size 024.
3. See Table 4A for line size conversion to mm.
LEGEND
Suction Riser Without Trap
Suction Riser With Trap
Suction Line to Condensing Unit
Short Vertical Riser Into
Condensing Unit:
38AKS013
38AKS014,016 — 13⁄8 in. OD
38AKS024
— 15⁄8 in. OD
— 11⁄8 in. OD
Fig. 4 — Suction Line Piping
9
INSTALL FILTER DRIER(S) AND MOISTURE INDICA-
TOR(S) — Every unit should have a filter drier and liquid-
moisture indicator (sight glass). In some applications, depending
on space and convenience requirements, it may be desirable
to install 2 filter driers and sight glasses. One filter drier and
sight glass may be installed at A locations in Fig. 5. Or, 2
filter driers and sight glasses may be installed at B locations.
2. Remove 1⁄4-in. flare cap from liquid valve Schrader port.
3. Attach refrigerant recovery device and recover holding
charge.
4. Remove runaround loop.
5. Install a field-supplied liquid moisture indicator in the pip-
ing immediately leaving outdoor unit.
6. If necessary, install field-supplied thermostatic expan-
sion valve(s) (TXVs) in air handler.
If 2 TXVs are installed and two-step cooling is desired,
install field-supplied liquid line solenoid valve ahead of the
upper TXV (see Fig. 5).
Select the filter drier for maximum unit capacity and mini-
mum pressure drop. Complete the refrigerant piping from
indoor unit to outdoor unit before opening the liquid and suc-
tion lines at the outdoor unit.
PROVIDE SAFETY RELIEF — A fusible plug is located
on the compressor crankcase or in the liquid line (Fig. 6).
Do not cap this plug. If local code requires additional safety
devices, install them as directed.
TXV — Thermostatic Expansion Valve
Fig. 5 — Location of Sight Glass(es)
and Filter Drier(s)
NOTE: 38AKS024 has a fusible plug in the liquid line.
Fig. 6 — Location of Fusible Plug (38AKS)
INSTALL LIQUID LINE SOLENOID VALVE — SOLE-
NOID DROP — It is recommended that a solenoid valve be
placed in the main liquid line (see Fig. 5) between condens-
ing unit (38AKS) and fan coil (40RM, 39 Series). (A liquid
line solenoid valve is required when the liquid line length
exceeds 100 ft [30.5 m] or when the condensing unit is con-
nected to a chiller barrel in a built-up chiller system.) This
valve prevents refrigerant migration (which causes oil dilu-
tion) to the compressor during the off cycle at low outdoor
ambient temperatures. The solenoid should be wired in par-
allel with the compressor contactor coil. This means of elec-
trical control is referred to as solenoid drop control.
Step 4 — Install Accessories — Field install
accessories such as winter start control or low-ambient con-
trol before proceeding with wiring. Refer to the instructions
shipped with the accessory.
Step 5 — Complete Electrical Connections
POWER WIRING — Unit is factory wired for voltage shown
on nameplate. Provide adequate fused disconnect switch within
sight from unit and readily accessible from unit, but out of
the reach of children. Lock switch open (off) to prevent power
from being turned on while unit is being serviced. Dis-
connect switch, fuses, and field wiring must comply with
national and local code requirements. See Tables 6A and 6B.
Route power wires through opening in unit end panel to
connection in unit control box as shown on unit label dia-
gram and in Fig. 7. Unit must be grounded.
INSTALL LIQUID LINE SOLENOID VALVE (Optional)
— CAPACITY CONTROL — If 2-step cooling is desired,
place a solenoid valve in the location shown in Fig. 5.
MAKE PIPING CONNECTIONS — Do not remove run-
around loop from suction and liquid line stubs in the com-
pressor compartment until piping connections are ready to
be made. Pass nitrogen or other inert gas through piping while
brazing to prevent formation of copper oxide.
Affix crankcase heater warning sticker to unit disconnect
switch.
CONTROL CIRCUIT WIRING — Control voltage is 24 v.
See Fig. 8 and unit label diagram for field-supplied wiring
details. Route control wires through opening in unit end panel
to connection in unit control box.
Recover holding charge prior to removal of runaround
piping loop.
1. Open service valves:
a. Discharge service valve on compressor.
b. Suction service valve on compressor.
c. Liquid line valve.
10
LEGEND
EQUIP GND — Equipment Ground
NEC
— National Electrical Code
Factory Wiring
Field Wiring
LEGEND
Compressor Contactor
C
—
—
—
—
HD
Heating Device
Fig. 7 — Main Power Supply Wiring
IFC
LLSV1
Indoor-Fan Contactor
Liquid Line Solenoid Valve 1 — Refrigerant Migration
Control
LLSV2
R
—
—
Liquid Line Solenoid Valve 2 — Capacity Control
Relay
Factory Wiring
Field Wiring
NOTES:
1. Combination LLSV plus IFC va should not exceed 30 va.
2. Do not exceed 5 va (24 vac) per coil.
3. If va values shown in Notes 1 and 2 must be exceeded, use
accessory relay transformer package 38AE900001 (60 Hz) or
38AD900003 (50 Hz and 380-3-60).
Fig. 8 — Remote Thermostat Wiring
Table 6A — Electrical Data (3 Ph/60 Hz)
UNIT
COMPR
FAN MOTORS (Single Phase)
FLA (ea)
Volts
UNIT
MOCP
(Fuse
Only)
Total
38AKS
Fan No.
Model
Supplied*
MCA
ICF
RLA
LRA
kW
Fans
Nameplate
Min
187
342
414
518
Max
1
2
501
201
601
101
208-230
380
253
418
528
660
62.5
35.0
29.1
22.8
178
101
81
100
50
40
35
43.6
24.0
20.0
15.7
170
93
4.3
4.3
2.3
1.8
3.7
3.7
1.9
1.8
013
2
1.41
1.41
1.41
1.41
460
77
575
67
62
501
201
601
101
208-230
380
187
342
414
518
253
418
528
660
69.3
38.0
31.7
25.6
199
112
84
100
60
50
40
49.3
26.5
22.1
17.9
191
104
80
4.3
4.3
2.3
1.8
3.7
3.7
1.9
1.8
014
2
2
2
460
575
73
69
501
201
601
101
208-230
380
187
342
414
518
253
418
528
660
87.5
49.3
40.7
33.0
274
153
124
100
125
80
60
50
63.6
36.0
29.3
23.8
266
145
120
96
4.3
4.3
2.3
1.8
3.7
3.7
1.9
1.8
016
460
575
501
201
601
101
208-230
380
187
342
414
518
254
418
508
632
93.4
49.7
48.1
40.1
353
199
177
124
150
80
80
60
67.9
34.6
34.7
28.8
345
191
173
120
4.3
4.3
2.3
1.8
3.7
3.7
1.9
1.8
024
460
575
LEGEND
Full Load Amps (Fan Motors)
*Units are suitable for use on electrical systems where voltage sup-
plied to the unit terminals is not below or above the listed limits.
FLA
—
—
ICF
Maximum Instantaneous Current Flow during start-up
(LRA of compressor plus total FLA of fan motors)
Total Fan Motor Input (kilowatts)
NOTES:
1. The MCA and MOCP values are calculated in accordance
with the National Electrical Code (NEC) article 440 (U.S.A.
standard).
kW
LRA
MCA
—
—
—
Locked Rotor Amps
Minimum Circuit Amps per NEC (U.S.A.),
Section 430-24
2. Motor RLA and LRA values are established in accordance
with Underwriters’ Laboratories (UL) Standard 1995 (U.S.A.
standard).
MOCP
RLA
—
—
Maximum Overcurrent Protection (amps)
Rated Load Amps (Compressor)
11
Table 6B — Electrical Data (3 Ph/50 Hz)
UNIT
COMPR
FAN MOTORS 230 v (Single Phase)
Volts
Supplied*
UNIT
38AKS
FLA (ea)
Total
MOCP
(Fuse
Only)
Fan No.
Model
MCA
ICF
RLA
LRA
kW
Fans
Nameplate
Min
Max
1
2
803
903
230
400
198
342
264
457
47.5
31.4
134
80
75
50
32.9
20.0
128
74
013
014
016
2
2
2
2.9
3.5
1.20
1.20
1.20
803
903
230
400
198
342
264
457
51.0
34.0
149
89
75
50
35.7
22.1
143
83
2.9
2.9
3.5
3.5
803
903
230
400
198
342
264
457
66.9
43.0
206
121
100
60
47.9
29.3
200
115
803
303
903
230
346
400
198
311
342
254
380
440
91.8
51.5
50.2
213
121
179
150
80
80
67.9
33.3
34.6
207
115
173
024
2
2.9
3.5
1.20
LEGEND
Full Load Amps (Fan Motors)
*Units are suitable for use on electrical systems where voltage sup-
plied to the unit terminals is not below or above the listed limits.
FLA
—
—
ICF
Maximum Instantaneous Current Flow during start-up
(LRA of compressor plus total FLA of fan motors)
Total Fan Motor Input (kilowatts)
NOTES:
1. The MCA and MOCP values are calculated in accordance
with the National Electrical Code (NEC) article 440 (U.S.A.
standard).
kW
LRA
MCA
—
—
—
Locked Rotor Amps
Minimum Circuit Amps per NEC (U.S.A.),
Section 430-24
2. Motor RLA and LRA values are established in accordance
with Underwriters’ Laboratories (UL) Standard 1995 (U.S.A.
standard).
MOCP
RLA
—
—
Maximum Overcurrent Protection (amps)
Rated Load Amps (Compressor)
7. Electrical power source must agree with nameplate
rating.
PRE-START-UP
IMPORTANT: Before beginning Pre-Start-Up or
Start-Up, review Start-Up Checklist at the back of this
book. The Checklist assures proper start-up of a unit
and provides a record of unit condition, application re-
quirements, system information, and operation at ini-
tial start-up.
8. Crankcase heater must be firmly locked into compressor
crankcase. Be sure crankcase is warm (heater must be on
for 24 hours before starting compressor).
9. Be sure compressor floats freely on the mounting springs
and that snubber washers can be moved with finger pres-
sure. See Compressor Mounting, page 8, and Fig. 3 for
loosening compressor bolts.
Leak Test and Dehydration — Leak test the entire
refrigerant system using soap bubbles and/or an electronic
leak detector. Evacuate and dehydrate entire refrigerant sys-
tem by use of methods described in GTAC II, Module 4,
System Dehydration.
Do not attempt to start the condensing unit, even
momentarily, until the following steps have been com-
pleted. Compressor damage may result.
System Check
Turn On Crankcase Heater — Turn on crankcase heater
for 24 hours before starting the unit to be sure all the
refrigerant is out of the oil. To energize the crankcase heater,
proceed as follows:
1. Set the space thermostat set point above the space tem-
perature so there is no demand for cooling.
1. Check all air handler(s) and other equipment auxiliary com-
ponents. Consult the manufacturer’s instructions regard-
ing any other equipment connected to the condensing unit.
If unit has field-installed accessories, be sure all are prop-
erly installed and correctly wired. If used, airflow switch
must be properly installed.
2. Backseat (open) compressor suction and discharge valves.
Now close valves one turn to allow refrigerant pressure
to reach test gages.
2. Close the field disconnect.
3. Turn the fan circuit breaker on. Leave the com-
pressor circuit breakers off. The crankcase heater is now
energized.
3. Open liquid line service valve.
Preliminary Charge — Refer to GTAC II, Module 5,
Charging, Recovery, Recycling, and Reclamation for charg-
ing methods and procedures. Charge each system with R-22
by the liquid charging method (through liquid service valve)
on the high side. Charge according to the values in the
Charging Chart, Fig. 10, 11, or 12.
4. Check tightness of all electrical connections.
5. Compressor oil level should be visible in sight glass. See
Fig. 9. Adjust the oil level as required. Refer to Pre-
liminary Oil Charge section. No oil should be removed
unless the crankcase heater has been energized for at least
24 hours.
6. Be sure unit is properly leak checked, dehydrated, and
charged. See Preliminary Charge, this page.
12
START-UP
Compressor crankcase heater must be on for 24 hours
before start-up. After the heater has been on for 24 hours,
the unit can be started. If no time has elapsed since the pre-
liminary charge step has been completed, it is unnecessary
to wait the 24-hour period.
Never charge liquid into the low-pressure side of sys-
tem. Do not overcharge. During charging or removal of
refrigerant, be sure indoor-fan system is operating.
Adjust Refrigerant Charge
Preliminary Checks
NOTE: Actual start-up and all refrigerant charge modifica-
tions should be done only under supervision of a qualified
refrigeration mechanic.
With all fans operating, adjust the refrigerant charge in
accordance with the unit charging charts located on the
inside of the control box doors and in Fig. 10-12.
Measure pressure at the liquid line service valve, being
sure Schrader depressor is used if required. Also, measure
liquid line temperature as close to the liquid service valve as
possible. Add charge until the pressure and temperature con-
ditions of the charging chart curve are met. If liquid pressure
and temperature point fall above curve, add charge. If liquid
pressure and temperature point fall below curve, reduce the
charge until the conditions match the curve.
If the sight glass is cloudy, check refrigerant charge again.
Ensure all fans are operating. Also ensure maximum
allowable liquid lift has not been exceeded. If charged per
chart and if the sight glass is still cloudy, check for a plugged
filter drier or a partially closed solenoid valve. Replace or
repair, as needed.
1. Ensure that compressor service valves are backseated.
2. Verify that each compressor floats freely on its mounting
springs.
3. Check that electric power supply agrees with unit name-
plate data.
4. Verify that compressor crankcase heater is securely in place.
5. Check that compressor crankcase heater has been on at
least 24 hours.
6. Note that compressor oil level is visible in the sight glass.
7. Recheck for leaks using same procedure as pre-
viously outlined in Pre-Start-Up section, Leak Test and
Dehydration.
8. If any leaks are detected, evacuate and dehydrate as pre-
viously outlined in Pre-Start-Up section, Leak Test and
Dehydration.
9. All internal wiring connections must be tight, and all bar-
riers and covers must be in place.
Preliminary Oil Charge — Compressor is factory
charged with oil (see Tables 1A-1D). When oil is checked at
start-up, it may be necessary to add or remove oil to bring
it to the proper level. One recommended oil level adjust-
ment method follows:
Check Compressor Oil Level — After adjusting the
refrigerant charge, allow the compressor to run fully loaded
for 20 minutes. Running oil level should be within view of
the crankcase sight glass. Stop the compressor at the field
power supply disconnect and check the crankcase oil level.
Add oil only if necessary to bring the oil into view in the
sight glass. If oil is added, run the compressor for an addi-
tional 10 minutes, then stop and check oil level. If the level
remains low, check the piping system for proper design for
oil return; also, check the system for leaks.
If the initial check shows too much oil (too high in the
sight glass) remove oil to proper level. See Preliminary Oil
Charge, this page, for proper procedure for adding and
removing oil. See Fig. 9.
When the above checks are complete, repeat the proce-
dure with the unit operating at minimum load conditions.
Unload the compressor by turning the control set point
adjustment nut counterclockwise until the adjustment nut stops.
The unloader is now at 0 psig (0 kPag) set point. If electric
actuated unloaders are installed, energize the solenoid to un-
load the compressor.
ADD OIL — Close suction service valve and pump down
crankcase to 2 psig (14 kPag). (Low-pressure switch must
be jumpered.) Wait a few minutes and repeat until pressure
remains steady at 2 psig (14 kPag). Remove oil fill plug above
the oil level sight glass, add oil through plug hole, and
replace plug. Run compressor for 20 minutes and check oil
level. See Fig. 9.
NOTE: Use only Carrier approved compressor oil. Ap-
proved sources are:
Petroleum Specialties Inc. . . . . . . . . . . . . . . . . Cryol 150A
Texaco, Inc. . . . . . . . . . . . . . . . . . . . . . . . . . Capella WF-32
Witco Chemical Co. . . . . . . . . . . . . . . . . . . . . . Suniso 3GS
Do not use oil that has been drained out, or oil that has
been exposed to atmosphere.
REMOVE OIL — Pump down compressor to 2 psig
(14 kPag). Loosen the 1⁄4-in. (6.4 mm) pipe plug at the com-
pressor base and allow the oil to seep out past the threads
of the plug.
Return unloader to original setting after checks are
complete.
NOTE: The crankcase will be slightly pressurized. Do not
remove the plug, or the entire oil charge will be lost.
Small amounts of oil can be removed through the oil pump
discharge connection while the compressor is running.
Start Unit — The field disconnect is closed, the fan cir-
cuit breaker is closed, and the space thermostat is set above
ambient so that there is no demand for cooling. Only the
crankcase heater will be energized.
Next, close the compressor circuit breaker and then reset
space thermostat below ambient so that a call for cooling is
ensured. If compressor does not start, set thermostat lower.
38AKS024
38AKS013,014,016
(06E COMPRESSOR)
(06D COMPRESSOR)
Fig. 9 — Operating Oil Levels
NOTE: Do not use circuit breaker to start and stop the com-
pressor except in an emergency.
After starting, there is a delay of at least 3 seconds before
compressor starts.
Final Checks — Ensure all safety controls are operat-
ing, control panel covers are on, and the service panels are
in place.
13
Fig. 10 — 38AKS013 and 38AKS024 Charging Chart
Fig. 11 — 38AKS014 Charging Chart
Fig. 12 — 38AKS016 Charging Chart
PRESSURE DIFFERENTIAL (difference between cylinder
load and unload points) is adjustable from 6 to 22 psig
(41.4 to 152 kPag). To adjust, turn pressure differential ad-
justment screw (Fig. 13) counterclockwise to its back stop
position. In this position, differential is 6 psig (41.4 kPag).
Next, turn adjustment clockwise to desired pressure differ-
ential setting. Every full turn clockwise increases differen-
tial by 1.5 psig (10.3 kPag).
OPERATING SEQUENCE
Cooling — When the first stage (TC1) of the cooling ther-
mostat closes, the timer starts. After approximately
3 seconds, the timer expires, energizing the compressor and
fan motor no. 1. When the liquid pressure builds to approxi-
mately 257 psig (1772 kPa), fan motor no. 2 is energized.
On demand for additional cooling capacity, the second stage
(TC2) of the cooling thermostat closes, energizing a field-
supplied liquid line solenoid (LLS) valve, which opens. This
increases the suction pressure, causing the compressor to
operate at higher capacity.
Head Pressure Control — Fan cycling is a standard
feature. The no. 2 fan cycles in response to changes in liquid
pressure. The switch cycles the fan off at 160 ± 10 psig
(1103 ± 69 kPa) as pressure decreases, and cycles it back on
at 255 ± 10 psig (1758 ± 69 kPa).
When fan switch is set at AUTO, the indoor unit fan cycles
with the compressor. When the switch is set at ON, the
indoor unit fan runs continuously.
At shutdown, the Time Guard II timer prevents the com-
pressor from restarting for approximately 5 minutes.
When installed, a field-supplied solenoid valve (wired in
parallel with the compressor contactor coil), shuts off the liq-
uid line to prevent refrigerant migration back to the com-
pressor during the off cycle.
Heating — The heating thermostat (TH) energizes a field-
supplied relay which operates heating controls and ener-
gizes the indoor unit relay. When the fan switch is set at AUTO,
the indoor unit fan cycles with the heating control. The
indoor unit fan runs continuously when the fan switch is set
at ON.
Causes of complete unit shutdown are: interruption of sup-
plied power, open compressor internal protector (IP), open
control circuit breaker, or an open high- or low-pressure safety
switch.
Fan Cycling — Head pressure control is accomplished
by cycling the fans. The no. 2 fan responds to liquid line
pressure, cycling on at approximately 255 psig (1758 kPa)
and off at approximately 160 psig (1103 kPa).
Winter Start Control (If Installed) — When the com-
pressor starts, the control’s bypass timer contacts close for
150 seconds, thereby bypassing the low-pressure switch dur-
ing start-up. After 150 seconds, the bypass timer contacts
open and the low-pressure switch is restored to the safety
circuit.
Fig. 13 — Compressor Capacity Control Unloader
Time Guard II Circuit — Circuit prevents short-
cycling by providing a delay of approximately 5 minutes
before restarting compressor after shutdown from safety
device action.
On start-up, the Time Guard II timer causes a delay of
approximately 3 seconds after thermostat closes.
On compressor shutdown, the timer recycles for approxi-
mately 5 minutes. During this time, the compressor cannot
restart.
SERVICE
Capacity Control — A suction pressure-actuated
unloader controls 2 cylinders and provides capacity control.
Unloaders are factory set (see Tables 1A-1D), but can be
field adjusted as described in the 2 following sections.
Refer to Fig. 14 and to label diagram on unit.
CONTROL SET POINT (cylinder load point) is adjustable
from 0 to 85 psig (586 kPa). To adjust, turn control set point
adjustment nut (Fig. 13) clockwise to its bottom stop. In this
position, set point is 85 psig (586 kPa). Next, turn adjust-
ment counterclockwise to desired control set point. Every
full turn counterclockwise decreases set point by 7.5 psig
(51.7 kPa).
Fig. 14 — Timer Sequence Chart
17
Winter Start Control (If Required) — Install Ac-
Outdoor Fans — Each fan is supported by a formed-
wire mount bolted to the fan deck and covered with a wire
guard. The exposed end of the motor shaft is covered with
a rubber boot. In case a fan motor must be repaired or re-
placed, be sure the rubber boot is put back on when the fan
is reinstalled and be sure the fan guard is in place before
starting the unit. Figure 15 shows the proper position of the
mounted fan. Fan motors have permanently lubricated
bearings.
cessory Package 38AE900021.
Crankcase Heater — The heater prevents refrigerant
migration and compressor oil dilution during shutdown when-
ever compressor is not operating. It is wired to cycle with
the compressor; the heater is off when compressor is run-
ning, and on when compressor is off.
Both compressor service valves must be closed whenever
the crankcase heater is deenergized for more than 6 hours.
The crankcase heater is operable as long as the control cir-
cuit is energized.
Lubrication
FAN MOTORS have sealed bearings. No provisions are made
for lubrication.
Compressor Protection
COMPRESSOR has its own oil supply. Loss of oil due to a
leak in the system should be the only reason for adding oil
after the system has been in operation. See Preliminary Oil
Charge section.
CIRCUIT BREAKER — Calibrated trip manual reset, am-
bient compensated, magnetic breaker protects against motor
overload and locked rotor conditions.
COMPRESSOR OVERTEMPERATURE PROTECTION (IP)
— A thermostat installed on compressor motor winding
reacts to excessively high winding temperatures and shuts
off the compressor.
Cleaning Coils — The coils can be cleaned with a vacuum
cleaner, washed out with low velocity water, blown out with
low-pressure compressed air, or brushed (do not use wire
brush). Fan motors are drip-proof but not waterproof. Do
NOT use acid cleaners.
Clean outdoor coil annually or as required by location or
outdoor air conditions. Inspect coil monthly, and clean as
required. Fins are not continuous through coil sections; dirt
and debris may pass through first section, become trapped
between the 2 rows of fins (38AKS013) or 3 rows of fins
(38AKS014-024) and restrict outdoor airflow. Use a flash-
light to determine if dirt or debris has collected between coil
sections. Clean coil as follows:
TIME GUARD II CONTROL — Control prevents com-
pressor from short cycling. See Operating Sequence.
CRANKCASE HEATER — Heater minimizes absorption of
liquid refrigerant by oil in crankcase during brief or ex-
tended shutdown periods. The control circuit is maintained
if compressor fan motor circuit breakers are turned off. The
main disconnect must be on to energize crankcase heater.
IMPORTANT: Never open any switch or disconnect
that energizes the crankcase heater unless unit is being
serviced or is to be shut down for a prolonged period.
After a prolonged shutdown on a service job, energize
the crankcase heater for 24 hours before starting the
compressor.
1. Turn off unit power.
2. Remove screws holding rear corner posts and top
cover in place. Pivot top cover up 12 to 18 in. (305 to
457 mm) and support with a rigid support. See Fig. 16.
3. Remove clips securing tube sheets together at the return
bend end of the coil. Carefully spread the ends of the coil
rows apart by moving the outer sections. See Fig. 17.
4. Using a water hose, or other suitable equipment, flush down
between the sections of coil to remove dirt and debris.
High-Pressure Switches — Switches have fixed,
nonadjustable settings. Switches are mounted on the
compressors.
Low-Pressure Switches — Switches have fixed,
nonadjustable settings. Switches are mounted on the
compressors.
5. Clean the remaining surfaces in the normal manner.
6. Reposition outer coil sections.
7. Reinstall clips which secure tube sheets.
8. Replace top cover and rear corner posts.
TO CHECK — Slowly close liquid shutoff valve and allow
compressor to pump down. Do not allow compressor
pump-down below 2 psig (13.8 kPa). Compressor should shut
down when suction pressure drops to cutout pressure in
Tables 1A-1D, and should restart when pressure builds up to
cut-in pressure shown.
18
Fig. 15 — Outdoor Fan
Fig. 17 — Coil Cleaning (Typical)
Fig. 16 — Pivot and Support Top Cover
19
TROUBLESHOOTING
PROBLEM
COMPRESSOR DOES NOT RUN
Contactor Open
SOLUTION
1. Power off.
1. Restore power.
2. Fuses blown in field power circuit.
3. No control power.
2. After finding cause and correcting, replace with correct size fuse.
3. Check control circuit breaker; reset if tripped or replace if defective.
4. Check thermostat setting.
4. Thermostat circuit open.
5. Time Guardா II device not operating.
6. Compressor circuit breaker tripped.
5. Check Time Guard II devices.
6. Check for excessive compressor current draw. Reset breaker;
replace if defective.
7. Safety device lock-out circuit active.
8. Low-pressure switch open.
7. Reset lock-out circuit at thermostat or circuit breaker.
8. Check for refrigerant undercharge, obstruction of indoor airflow, or
whether compressor suction shutoff valve is fully open. Make sure liquid
line solenoid valve(s) is open.
9. High-pressure switch open.
9. Check for refrigerant overcharge, obstruction of outdoor airflow, air in
system, or whether compressor discharge valve is fully open. Be sure
outdoor fans are operating correctly.
10. Compressor overtemperature switch open.
11. Loose electrical connections.
12. Compressor stuck.
10. Check for open condition. Allow for reset. Replace if defective.
11. Tighten all connections.
12. See compressor service literature.
Contactor Closed
1. Compressor leads loose.
2. Motor windings open.
1. Check connections.
2. See compressor service literature.
3. Single phasing.
3. Check for blown fuse. Check for loose connection at compressor terminal.
COMPRESSOR STOPS ON HIGH-PRESSURE SWITCH
Outdoor Fan On
1. Replace switch.
1. High-pressure switch faulty.
2. Reversed fan rotation.
3. Airflow restricted.
2. Confirm rotation, correct if necessary.
3. Remove obstruction.
4. Air recirculating.
4. Clear airflow area.
5. Noncondensables in system.
6. Refrigerant overcharge.
7. Line voltage incorrect.
8. Refrigerant system restrictions.
5. Recover refrigerant and recharge as required.
6. Recover refrigerant as required.
7. Consult power company.
8. Check or replace filter drier, expansion valve, etc. Check that compressor
discharge service valve is fully open.
Outdoor Fan Off
1. Fan slips on shaft.
1. Tighten fan hub setscrews.
2. Check power and capacitor.
3. Replace bearings.
2. Motor not running.
3. Motor bearings stuck.
4. Motor overload open.
4. Check overload rating. Check for fan blade obstruction.
5. Replace motor.
5. Motor burned out.
COMPRESSOR CYCLES ON LOW-PRESSURE SWITCH
Indoor-Air Fan Running
1. Compressor suction service valve partially closed.
1. Open valve fully.
2. Liquid line solenoid valve(s) fails to open.
2. Check liquid line solenoid valve(s) for proper operation. Replace if
necessary.
3. Filter drier plugged.
3. Replace filter drier.
4. Expansion valve power head defective.
5. Low refrigerant charge.
4. Replace power head.
5. Add charge. Check low-pressure switch setting.
20
TROUBLESHOOTING (cont)
PROBLEM
SOLUTION
COMPRESSOR CYCLES ON LOW-PRESSURE SWITCH (cont)
Airflow Restricted
1. Coil iced up.
2. Coil dirty.
1. Check refrigerant charge.
2. Clean coil fins.
3. Air filters dirty.
4. Dampers closed.
3. Clean or replace filters.
4. Check damper operation and position.
Indoor-Air Fan Stopped
1. Electrical connections loose.
1. Tighten all connections.
2. Replace relay.
2. Fan relay defective.
3. Motor overload open.
3. Power supply.
4. Motor defective.
4. Replace motor.
5. Fan belt broken or slipping.
COMPRESSOR RUNNING BUT COOLING INSUFFICIENT
Suction Pressure Low
5. Replace or tighten belt.
1. Add refrigerant.
1. Refrigerant charge low.
2. Head pressure low.
2. Check refrigerant charge.
Check outdoor-air fan thermostat settings.
3. Air filters dirty.
3. Clean or replace filters.
4. Replace power head.
5. Check low-pressure setting.
6. Remove obstruction.
4. Expansion valve power head defective.
5. Indoor coil partially iced.
6. Indoor airflow restricted.
Suction Pressure High
1. Unloaders not functioning.
1. Check unloader adjustments.
Check unloader setting.
2. Compressor valve defective.
3. Heat load excessive.
2. See compressor service literature.
3. Check for open doors or windows in vicinity of fan coil.
UNIT OPERATES TOO LONG OR CONTINUOUSLY
1. Low refrigerant charge.
2. Control contacts fused.
1. Add refrigerant.
2. Replace control.
3. Air in system.
3. Purge and evacuate system.
4. Clean or replace.
4. Partially plugged expansion valve or filter drier.
SYSTEM IS NOISY
1. Piping vibration.
1. Support piping as required.
2. Compressor noisy.
2. Check valve plates for valve noise. Replace compressor if
bearings are worn.
COMPRESSOR LOSES OIL
1. Leak in system.
1. Repair leak.
2. Crankcase heaters not energized during shutdown.
2. Check wiring and relays. Check heater and replace if
defective.
3. Improper interconnecting piping design.
FROSTED SUCTION LINE
3. Check piping for oil return. Replace if necessary.
Expansion valve admitting excess refrigerant.
HOT LIQUID LINE
Adjust expansion valve.
1. Shortage of refrigerant due to leak.
2. Expansion valve opens too wide.
FROSTED LIQUID LINE
1. Repair leak and recharge.
2. Adjust expansion valve.
1. Restricted filter drier.
1. Remove restriction or replace.
2. Replace valve.
2. Liquid line solenoid valve partially closed.
COMPRESSOR WILL NOT UNLOAD
1. Defective unloader.
1. Replace unloader.
2. Replace valve.
3. Rewire correctly.
4. Replace spring.
2. Defective capacity control solenoid valve (if used).
3. Miswired capacity control liquid line solenoid (if used).
4. Weak, broken, or wrong valve body spring.
COMPRESSOR WILL NOT LOAD
1. Miswired capacity control liquid line solenoid (if used).
2. Defective capacity control solenoid valve (if used).
3. Plugged strainer (high side).
1. Rewire correctly.
2. Replace valve.
3. Clean or replace strainer.
4. Clean or replace the necessary parts.
4. Stuck or damaged unloader piston or piston ring(s).
21
Copyright 1998 Carrier Corporation
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1
4
PC 111
Catalog No. 563-701
Printed in U.S.A.
Form 38AKS-3SI
Pg 22
9-98
Replaces: 38AKS-2SI
Tab 3a 2a
START-UP CHECKLIST
A. Preliminary Information
OUTDOOR: MODEL NO.
INDOOR: AIR HANDLER MANUFACTURER
MODEL NO.
SERIAL NO.
SERIAL NO.
ADDITIONAL ACCESSORIES
B. Pre-Start-Up
OUTDOOR UNIT
IS THERE ANY SHIPPING DAMAGE?
IF SO, WHERE:
(Y/N)
(Y/N)
WILL THIS DAMAGE PREVENT UNIT START-UP?
(Y/N)
CHECK POWER SUPPLY. DOES IT AGREE WITH UNIT?
HAS THE GROUND WIRE BEEN CONNECTED? (Y/N)
HAS THE CIRCUIT PROTECTION BEEN SIZED AND INSTALLED PROPERLY?
ARE THE POWER WIRES TO THE UNIT SIZED AND INSTALLED PROPERLY?
(Y/N)
(Y/N)
HAVE COMPRESSOR HOLDDOWN BOLTS BEEN LOOSENED (Snubber washers are snug, but not tight)?
(Y/N)
CONTROLS
ARE THERMOSTAT AND INDOOR FAN CONTROL WIRING
CONNECTIONS MADE AND CHECKED?
(Y/N)
ARE ALL WIRING TERMINALS (including main power supply) TIGHT?
HAS CRANKCASE HEATER BEEN ENERGIZED FOR 24 HOURS?
(Y/N)
(Y/N)
INDOOR UNIT
HAS WATER BEEN PLACED IN DRAIN PAN TO CONFIRM PROPER DRAINAGE?
ARE PROPER AIR FILTERS IN PLACE? (Y/N)
HAVE FAN AND MOTOR PULLEYS BEEN CHECKED FOR PROPER ALIGNMENT?
(Y/N)
(Y/N)
DO THE FAN BELTS HAVE PROPER TENSION?
(Y/N)
HAS CORRECT FAN ROTATION BEEN CONFIRMED?
(Y/N)
PIPING
ARE LIQUID LINE SOLENOID VALVES LOCATED AT THE INDOOR COILS AS REQUIRED?
HAVE LEAK CHECKS BEEN MADE AT COMPRESSOR, OUTDOOR AND INDOOR COILS,
(Y/N)
TXVs (Thermostatic Expansion Valves), SOLENOID VALVES, FILTER DRIERS, AND FUSIBLE PLUGS
WITH A LEAK DETECTOR? (Y/N)
LOCATE, REPAIR, AND REPORT ANY LEAKS.
HAVE ALL COMPRESSOR SERVICE VALVES BEEN FULLY OPENED (BACKSEATED)?
(Y/N)
HAVE LIQUID LINE SERVICE VALVES BEEN OPENED?
(Y/N)
IS THE OIL LEVEL IN EACH COMPRESSOR CRANKCASE VISIBLE IN THE COMPRESSOR SIGHT GLASSES?
(Y/N)
CHECK VOLTAGE IMBALANCE
LINE-TO-LINE VOLTS:
(AB + AC + BC)/3 = AVERAGE VOLTAGE =
MAXIMUM DEVIATION FROM AVERAGE VOLTAGE =
AB
V
AC
V
BC
V
V
V
VOLTAGE IMBALANCE = 100 X (MAX DEVIATION)/(AVERAGE VOLTAGE) =
%
IF OVER 2% VOLTAGE IMBALANCE, DO NOT ATTEMPT TO START SYSTEM!
CALL LOCAL POWER COMPANY FOR ASSISTANCE.
CL-1
C. Start-Up
CHECK INDOOR UNIT FAN SPEED AND RECORD.
CHECK OUTDOOR UNIT FAN SPEED AND RECORD.
AFTER AT LEAST 10 MINUTES RUNNING TIME, RECORD THE FOLLOWING MEASUREMENTS:
OIL PRESSURE
SUCTION PRESSURE
SUCTION LINE TEMP
DISCHARGE PRESSURE
DISCHARGE LINE TEMP
ENTERING OUTDOOR UNIT AIR TEMP
LEAVING OUTDOOR UNIT AIR TEMP
INDOOR UNIT ENTERING-AIR DB (dry bulb) TEMP
INDOOR UNIT ENTERING-AIR WB (wet bulb) TEMP
INDOOR UNIT LEAVING-AIR DB TEMP
INDOOR UNIT LEAVING-AIR WB TEMP
COMPRESSOR AMPS (L1/L2/L3)
/
/
CHECK THE COMPRESSOR OIL LEVEL SIGHT GLASSES; ARE THE SIGHT GLASSES SHOWING
OIL LEVEL IN VIEW? (Y/N)
NOTES:
Copyright 1998 Carrier Corporation
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 PC 111 Catalog No. 563-701 Printed in U.S.A. Form 38AKS-3SI CL-2 9-98 Replaces: 38AKS-2SI
Tab 3a 2a
4
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