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SG-40MAHB-01: Service Manual
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32
DIAGNOSIS AND SOLUTION (CONT)
Inverter compressor drive error diagnosis and solution (P4)
Malfunction Decision Conditions
An abnormal inverter compressor drive is detected by a special detection circuit, including communication signal detection, voltage detection
and compressor rotation speed signal detection.
Possible Causes:
• Wiring mistake
• IPM malfunction
• Outdoor fan assembly faulty
• Compressor malfunction
• Outdoor PCB faulty
Troubleshooting
Check the wiring between the main PCB
and the compressor.
Correct the connection or replace
the wires and connectors.
Yes
No
Check the IPM.
No
Yes
Replace the IPM board or replace
the main PCB.
Check the outdoor fan and the
outdoor unit ventilation.
No
Refer to the
Fan Speed Out of Control
Malfunction solution.
Yes
Check the compressor resistance values.
No
Replace the compressor.
Yes
Replace the outdoor main PCB.