Applicable Systems
Copeland Scroll Compressor (CoreSense/Comfort Alert)
Symptoms
The compressor reports a start failure. The compressor failed to start within the allotted time after receiving the start command.
Possible Causes
- Locked rotor due to mechanical seizure or liquid refrigerant in cylinders
- Start capacitor or start relay failure
- Voltage drop during starting preventing motor acceleration
Troubleshooting Steps
- Step 1: Check for liquid refrigerant in the compressor by inspecting crankcase heater operation
Crankcase heater is energized and warm - Step 2: Test start capacitor capacitance and start relay contacts
Capacitor and relay meet specifications - Step 3: Measure voltage at compressor terminals during start attempt
Voltage drop is less than 15 percent of rated value
How to Reset
To reset: Eliminate the start failure cause, then cycle the compressor control power.
Source: Copeland Scroll Compressor Service Manual, Emerson Climate Technologies
Category: Refrigeration