Haier N Series Service Manual page 42

10.4.5 IPM protection
Outdoor display: LED1 flash 2 times
Method of IPM protection is detected by checking the compressor running condition and so on
Malfunction
Detection
Malfunction
Decision The compressor faulty leads to IPM protection
Conditions circuit component of IPM is broken and led to IPM protection
Supposed
Causes IPM protection dues to faulty PCB of IPM module
Troubleshooting * Caution Be sure to turn off power switch before connect or disconnect connector,
Electrify the machine again and turn it on with
the remote controller,If malfunctions are reported
before or upon the compressor being started up.
The compressor is started normally,
but malfunctions are reported after it
has run for some time.
1 The system may have been over(like,capillary clogging or electronic expansion valve faulty ) or under
charged with gas, which can be judged through the pressure of the measuring system.
2 The shaft of compressor is seized and the compressor needs replacing.
The system leads to IPM protection due to over current
IPM protection dues to the compressor faulty
Compressor wiring disconnected
else parts damage may be occurred.
Test IPM module resistance between P and U,V,W .
Then test IPM module resistance between N and U,V,W.
The resistances range are between 1M
IPM Module is damaged
and needs replacing.
40
Service diagnosis
with 10M .and they
are similar.
Domestic air conditioner
or