innovair NIN1225C2V31, Service Manual

Page: 52 / 82

9.3.8 Inverter compressor drive error diagnosis and solution(P4)
Error Code
P4
Malfunction decision
conditions 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.
Supposed causes
●
Wiring mistake
●
IPM malfunction
●
Outdoor fan ass’y faulty
●
Compressor malfunction
●
Outdoor PCB faulty
Trouble shooting:
Check if the wiring between main
PCB and compressor connected by
error and if the wires and connectors
are broken?
Correct the connection or replace
the wires and connectors.
Yes
No
IPM continuity check. Check if the
IPM terminal resistance values are
uniform. Refer to page 64.
Replace the IPM board or replace the
main PCB if the IPM board and main
PCB are integrated together.
No
Check if the outdoor fan runs
properly or the outdoor unit
ventilation is good.
Yes
No
For 3D inverter models, r
efer to the solution of fan speed
has been out of control malfunction . Find out the
cause and have it solved. For other models, please
refer to the below remark, check whether the
resistance of the fan motor is normal. If not, replace
the fan motor.
Yes
Check if the compressor resistance
values are uniform .Refer to page 63.
No Replace the compressor.
Yes
Replace the outdoor main PCB if the
main PCB and IPM are separate.
Remark
：
1) MS9A-09HRDN1-MP0W, MS9A-12CRFN1-MS0W(B), MS9A-12HRDN1-MP0W models: Measure the black pin and red pin of the motor connector, the
resistance should be around 293Ω at 20
℃
(68
℉
)
2) MS9A-18HRDN1-MP0W model: Measure the black pin and red pin of the motor connector, the resistance should be around 56Ω at 20
℃
(68
℉
)
3) MS9A-24HRDN1-MP0W model: Measure the black pin and red pin of the motor connector, the resistance should be around 88.5Ω at 20
℃
(68
℉
)
4) MS9A-24HRDN1-MS0W: Measure the black pin and red pin of the motor connector, the resistance should be around 56.5Ω at 20
℃
(68
℉
)
50
Innovair Corporation Nexxos Inverter