CNG-92200H
Revised 08-00
00-02-0149
F W M u r p h y
Control Systems for
Alternative Fuel
Fueling Stations
Standard Control Systems for
CNG Fueling Stations
Designed for the small fueling facility...monitoring
and controlling electric motor driven compressor.
LEVEL I
LEVEL I is an entry level controller system
designed for the small fueling facility requiring
only basic start and stop of the compressor
and monitoring basic shutdown functions. It
monitors and controls the electric motor
driven compressor and the system loading and
unloading devices.
The LEVEL I controller is an extremely
powerful system, yet user friendly. Its design
incorporates the high technology Murphy
SELECTRONIC® Micro-Controller™ series.
Features:
Automatic start and stop control
Operating parameters field adjustable
without reprogramming
Includes hourmeter
Extremely user friendly
Operates load/unload devices
Compatible with stand alone
priority/sequential controls (see below)
NEMA 4, 7, and 9 enclosure
Additional Controls
Stand Alone Priority and
Sequential Controller
The Murphy SELECTRONIC®
Priority/Sequential Controller
will monitor the Cascade or
other high pressure storage
banks and control the electric
sequencing valves. The Priority
Valves will sequence at operator
selectable levels to fill the
storage on fast fill packages. It
will also monitor the vehicle
dispenser flow rate and
pressure, and will control the
Sequential Valves and Shut-off
Valves to maximize filling the
vehicle in the minimum amount
of time.
2
Suitable for larger stations with
simplex or duplex compressor(s).
LEVEL II
LEVEL II is a mid-range system
designed for the larger stations
with more shutdown inputs
being monitored than the LEVEL I
control system. The LEVEL II
system performs all the functions
of the LEVEL I, plus is available
for both single or dual electric
motor or engine drive
applications. A SELECTRONIC®
Micro-Controller™ monitors
control functions and displays
status and faults in a two line
alphanumeric LCD display. By
selecting the appropriate Murphy
SELECTRONIC® Micro-Controller™
for the specified hazardous area
classification (Div. 1 or Div. 2),
non-explosion-proof end devices
can be used. The LEVEL II
Features:
Automatic start/stop control
for electric motor or engine
driver(s)
Operating parameters
field adjustable without
reprogramming
Available for NEC Class I,
Division 1 or Division 2,
Group D
Expandable to interface with
multiple compressors or
multiple station controls
Reliable microprocessor-based
control circuitry
RS485 communications port
Wide variety of optional
features
Operates load/unload devices
SWICHGAGE® instruments
included in control panel
Extremely user friendly
12, 24 VDC or 120 VAC power
required
Includes hourmeter
Accepts discrete analog inputs
Compatible with stand alone
priority/sequential controls
(see page 5)
Tachometer on
engine drive units
NEMA 3 enclosure
controller is housed in a NEMA 3
weatherproof enclosure.
3
LEVEL II Div. 2 Control System
Monitor and control the entire fueling system
including the Priority/Sequential valve operations.
Communications modem on-board.
LEVEL III
LEVEL III is a comprehensive system
designed to monitor and control the
entire fueling system. It is available
for both simplex or duplex electric
motor or engine driven systems.
The Murphy SELECTRONIC® Micro-
Controller™ sequentially controls the
compressor operations. It also controls
the priority valves to maintain
adequate storage pressure and the
sequential valves which ensure
maximum fill in minimum time.
A built-in temperature compensator
assures optimum fills.
Features:
PLC capabilities:
Monitor 20 analog inputs
120 VAC control circuit for customer
supplied motor contactor
Reliable microprocessor based
control circuitry
Available for areas rated NEC Class
I, Division 1 or Division 2, Group
D, and non-hazardous locations
Built-in, two-line alphanumeric
display
Operates load/unload devices
Includes hourmeter
Automatic start/stop control for
electric motors or engine drivers
Control of Priority and
Sequential Valves
Monitor 40 optically isolated
discrete inputs
Tachometer on engine
drive units
Provides 32 open collector outputs
• Operating parameters
adjustable via three button
operator key pad–no
Expandable to interface with
multiple compressors, pumps,
vaporizers, or multiple station
controls
Remote communication is
possible through the
optional modem.
programming needed
• Built-in security to prevent
unauthorized system
RS485 and RS232
communication ports
The LEVEL III is
extremely flexible,
user friendly and
parameter manipulation
Optional modem
• Operating parameters stored in
EEPROM–memory maintained
during power outage
can be expanded to cover a wide
range of CNG fueling facilities.
Temperature compensation
24 VDC or 120 VAC
power required
The LEVEL III control system is rated
for hazardous and non-hazardous
locations.
NEMA 3 enclosure
LEVEL III Simplex
LEVEL III Duplex
4
Custom Valve Panels
Priority/Sequential Valve Panels
Murphy offers Priority/Sequential
Valve Panels complete with
Murphy Pressure Transmitters for
use with the LEVEL III control
system or the Murphy Stand-
Alone Priority/Sequential
Controller. These panels were
designed to fail close valves for
optimum operation. These
panels can be provided on a plate
or in a free standing NEMA 3
weatherproof enclosure.
Valve Panel for 2 fast fill drops, 1 slow fill
header, and 3 bank cascade storage.
Valve Panel for 4 fast fill drops, 1 slow
fill header, and 3 bank cascade storage.
Retrofit and Service Support
Murphy strives to offer the most
effective and timely support in the
industry. Whether your needs are
panel service, re-programming or
complete system upgrades using
dependable and proven Murphy
equipment, our qualified staff is
eager to assist.
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Layout of Typical CNG Fueling Station
LEVEL I
or
Compressor
Driver
LEVEL II
Control
System
Slow Fill
Header
PT
Optional Bypass
Valves (for fast fill)
LEVEL III
Control
Priority
Valves
System
H
DOT
PT
Priority/
Sequential
Valve
Control
Panel
Priority/Sequential
Valve Panel*
Cascade
M
PT
L
Storage Tanks
PT
Sequential
Valves
(2-drop
panel)
PT
PT
†
Dispenser
* These items are not included in a
LEVEL III control system.
Order seperately.
†
For this standard configuration, the
dispenser must provide a dry contact
closure to initiate a fill and a 4-20 mA
flow rate signal for each drop.
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