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Troubleshooting 18,000 & 24,000 Units
IPM Protection Malfunction (unit will not run)
Fault & Status
Possible Causes
1. Dirty indoor and outdoor coils
2. Faulty indoor or outdoor fans
3. High system pressure
4. Over charge of refrigerant
IPM Protection
Status:
During cooling mode, compressor will stop,
indoor fan will run. Heating mode all units
stop.
Are the compressor terminal
connected properly?
Yes
Correct wiring
problem
No
Replace Compressor
Is the resistance normal?
No
End Troubleshooting
Yes
Start Troubleshooting after unit
is powered off for 3 minutes
Test the isolation impedance between
the three phases of the compressor
and copper tubing
No
Check the compressor winding
resistance
Is the resistance above
500M
Ω
?
Replace the outdoor mainboard
Is Malfunction eliminated?
No
