4–39
T-372
AL024
Compressor IP Open
Cause:
Compressor internal protector (IP) is open.
Component
Compressor
Troubleshooting
Shut down unit disconnect power and check resistance of compressor
windings at contactor T1-T2, T2-T3.
Corrective Action
Monitor unit, if alarm remains active or is repetitive replace the compressor
at the next available opportunity. See Compressor Service,
AL025
Condenser IP Open
Cause:
Condenser fan motor internal protector (IP) is open.
Component
Insufficient Air Flow
Troubleshooting
Shut down unit and check condenser fan for obstructions.
Corrective Action
Remove obstructions.
Component
Condenser Fan Motor
Troubleshooting
Shut down unit, disconnect power. Check resistance at harness between
CA23 and CA11. If open, check condenser fan motor IP at plug connection
pins 4 & 6.
Corrective Action
Replace defective condenser fan motor. See Condenser Fan Motor
Assembly Service,
AL026
All Supply / Return Probes Failure
Cause:
Sensors out of range.
Component
All sensors detected as out of range.
Troubleshooting
Perform pre-trip P5.
Corrective Action
If P5 passes, no further action is required.
If P5 fails, replace the defective sensor as determined by P5. See
AL027
Analog to Digital Accuracy Failure
Cause:
Controller AD converter faulty.
Component
Controller
Troubleshooting
Power cycle the unit. If the alarm persists, it indicates a defective
microprocessor.
Corrective Action
Replace defective microprocessor. See Controller Service
.
AL028
Low Suction Pressure
Cause:
Suction pressure too low for normal operation.
Component
N/A
Troubleshooting
Power cycle the unit.
Corrective Action
Resetting the unit may correct problem. Check charge. Monitor the unit.