Fisher FSAIF-Pro-95AE2 Service Manual page 49

9.2.10 Inverter compressor drive error diagnosis and solution(P4)
Error Code
Malfunction decision
conditions
Supposed causes
Trouble shooting:
P4
An abnormal inverter compressor drive is detected by a special
detection circuit, including communication signal detection,
voltage detection, compressor rotation speed signal detection
and so on.
Wiring mistake
●
IPM malfunction
●
Outdoor fan ass'y faulty
●
Compressor malfunction
●
Outdoor PCB faulty
●
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