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CONTROLS TROUBLESHOOTING GUIDE
The following are recommended service actions. Observe all instructions noted elsewhere in this manual.
All electrical service is to be performed only by a qualified electrician.
Symptom Recommended action
No display,
Compressor stopped
Check incoming power to the compressor unit. Ensure that the
disconnect is on and that fuses have not blown (or circuit beaker
tripped). If power is being properly supplied to the control box,
check the fuses located at the fan starter, the control transformer
fuses, and the wiring to connector CN-6.
Compressor will not start To operate, the controller must be placed into an operating mode
(e.g.AUTO); press the [STOP/RESET] key to put the control into
the READY state, then select a mode with the operating mode
keys. In AUTOMATIC and SEQUENCE modes, compressors will
not start until the pressure drops below the reset pressures.
Display indicates
"NOT BLOWN DOWN"
The controller prevents attempts to start the main motor if the
reservoir pressure is over 5 psig. Pressure continues to be relieved
from the reservoir while this message is on, and the compressor
will start automatically after the pressure has dropped. If this
message remains with NO pressure in the reservoir, follow the
transducer zeroing procedure found in the controls adjustment
section.
Display indicates
"REMOTE HALT"
The controller is provided with an input for user-furnished remote
controls. This display indicates that 120 volt is removed from
terminal 6 of the terminal strip. Check all connections of the factory
installed jumper, or the customer- provided controls, if applicable.
Display indicates
"SHUTDOWN"
If the display indicates "SHUTDOWN", refer to the shutdown
troubleshooting section for assistance. In addition to the messages
shown, there are several internal and system diagnostics
performed by the controller. Consult the factory for additional
assistance.
Compressor runs,
but does not load
In the CONSTANT RUN and LOW DEMAND modes, the
compressor will not load until the pressure drops below reset
pressure. Refer to the operating instructions for further information.
If pressure is below the reset pressure, check that the inlet valve
operates freely. Check that the TVO, TVC, IVO and IVC valves are
wired and operating properly.
Compressor runs, unloads
at low pressure
If the inlet valve closes at low pressure, check the wiring to the
blowdown valve and the piping and check valves in its discharge
line.
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