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Service Manual
Installation and Maintenance
3. IPM protection, desynchronizing malfunction, phase current of compressor is overcurrent (AP1 below is
control board of outdoor unit)
Main detection point:
If control board AP1 and compressor COMP is well connected? If they are loosened? If the connection sequence is
correct?
Is voltage input in the normal range (Test the voltage between L, N of wiring board XT by DC voltage meter)?
If coil resistance of compressor is normal? Is compressor coil insulating to copper pipe well?
If the work load of unit is heavy? If radiating of unit is well?
If the refrigerant charging is appropriate?
Malfunction diagnosis process: