Trouble Shooting
Operation & Maintenance Manual 69
Symptom
Unit does not run
Compressor operates too
long continuously
Possible Cause
Possible Remedy
Check over current protection device
Check no-fused disconnect
(if equipped)
Restore power to unit
Check for leak and add refrigerant
Check unit configuration
Check Alarm status. See separate alarm trouble shooting
procedure and follow trouble shooting instructions
Check the PLC input channels also to verify alarm status
Input
Check fulfillment of oil heating time
Check fulfillment of comp start delay time
Check chilled water temp out
Check water flow
Check for leak and add refrigerant
Replace the contactors
Purge water loop
Remove refrigerant and recharge
Check Alarm status. See separate alarm trouble shooting
procedure and follow trouble shooting instructions
Check for temperature inputs. See operation and control.
Check capacity control overrides
Check the PLC input channels also to verify alarm status
Input
Check for power to unit
Low refrigerant charge
Wrong or incorrect unit
configuration
Active alarm
Active operating mode
Low refrigerant charge
Compressor or control con-
tacts welded
Air in chilled water loop
Non-condensables in refriger-
ant circuit
Active alarm
Active operating mode
Table 25
Circuit does not run