Operating instructions

89
Table 58 — Troubleshooting
LEGEND
SYMPTOM POSSIBLE CAUSE POSSIBLE REMEDY
Unit Does Not Run Check for power to unit • Check overcurrent protection device.
• Check non-fused disconnect (if equipped).
• Restore power to unit.
Wrong or incorrect unit
configuration
Check unit configuration.
Active alarm Check Alarm status. See the Alarms and Alerts section
and follow
troubleshooting instructions.
Active operating mode Check for Operating Modes. See the Operating Modes
section and follow troubleshooting instructions
Unit Operates too
Long or
Continuously
Low refrigerant charge Check for leak and add refrigerant.
Compressor or control
contacts welded
Replace contactor or relay.
Air in chilled water loop Purge water loop.
Non-condensables in
refrigerant circuit.
Remove refrigerant and recharge.
Inoperative EXV • Check EXV, clean or replace.
• Check EXV cable, replace if necessary.
• Check EXV board for output signal.
Load too high Unit may be undersized for application
Circuit Does Not Run Active alarm Check Alarm status. See the Alarms and Alerts section
and follow troubleshooting instructions.
Active operating mode Check for Operating Modes. See the Operating Modes
section and follow troubleshooting instructions.
Circuit Does Not
Load
Active alarm Check Alarm status. See the Alarms and Alerts section
and follow troubleshooting instructions.
Active operating mode Check for Operating Modes. See the Operating Modes
section and follow troubleshooting instructions.
Low saturated suction
temperature
See Operating Modes 21, 22 and 23.
High circuit suction superheat The circuit capacity is not allowed increase if circuit super-
heat is greater than 36°F (20 C). See Alarms 59-61 for
potential causes.
Low suction superheat The circuit capacity is not allowed to increase if the circuit
superheat is less than 18° F (10° C). See Alarms 62-64 for
potential causes.
Compressor Does
Not Run
Active alarm Check Alarm status. See the Alarms and Alerts section
and follow troubleshooting instructions.
Active operating mode Check for Operating Modes. See the Operating Modes
section and follow troubleshooting instructions.
Inoperative compressor
contactor
• Check control wiring.
• Check scroll protection module.
• Check contactor operation, replace if necessary.
Chilled Water Pump
is ON, but the
Machine is OFF
Cooler freeze protection Chilled water loop temperature too low. Check cooler
heater.
EXV — Electronic Expansion Valve