Carlyle 5F20 - Appendix A - Troubleshooting

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APPENDIX A — TROUBLESHOOTING
TROUBLE/SYMPTOM PROBABLE CAUSE REMEDY
Compressor will not start
Power off. Check main switch, fuse and wiring.
Thermostat set too high. Reset thermostat.
Thermal overload switch open. Reset switch.
Oil safety switch open. Reset switch.
Dirty contacts. Clean all control contacts.
Loose electrical connections or faulty wiring. Tighten connections; check wiring and rewire.
Compressor motor burned out. Check and replace if defective.
Liquid line solenoid valve closed.
Check for burned-out holding coil. Replace if
defective.
Evaporator fan off. Check fuses, overload. Restart.
Evaporative condenser or cooling tower fan or
pump not operating.
Check fuses, overloads and controls. Restart.
Compressor cycles intermittently
Low-pressure switch erratic in operation.
Check for clogged tubing to switch. Check switch
setting.
Low refrigerant charge. Add refrigerant.
Capacity control setting incorrect. Reset.
Thermostat differential too narrow. Reset.
Suction valve closed or throttled. Open up valve.
Compressor cycles on high pressurestat
Tubing to pressurestat restricted. Check and clean tubing.
Faulty pressurestat. Repair or replace.
Refrigerant overcharge. Remove excess refrigerant.
Insufficient condenser water flow or clogged
condenser.
Adjust water regulating valve to condenser.
Clean condenser.
Discharge service valve not fully open. Open valve.
Air in system. Purge air.
Condenser water pump off. Check pump and start.
High discharge pressure
Condenser inlet water temperature too high.
Increase water quantity by adjusting water
regulating valve. Use colder water.
Insufficient water flow through condenser.
Readjust water regulating valve. Increase size of
water supply main to condenser.
Plugged or scaled condenser tubes. Clean tubes.
Discharge service valve partially closed. Open valve.
Refrigerant overcharge. Remove excess refrigerant.
Air in system. Purge air.
Low discharge pressure
Excessive water flow through condenser. Adjust water regulating valve.
Suction service valve partially closed. Open valve.
Leaky compressor suction valves.
Examine valve discs and valve seats. Replace if
worn.
Worn piston rings. Replace.
Flooding Defective or improperly set expansion valve.
Reset to 5°F-10°F superheat. Valve operation
must be stable (no hunting).
Low suction pressure
Low refrigerant charge. Add refrigerant.
Excessive superheat. Reset expansion valves.