Ipm Protection - Haier HSU12 Service Manual

7.3.3 IPM protection

LED1 flash 2 times:
IPM protection is detected by checking the compressor running condition and so on.
Turn off the power.check if
the compressor
Check the IPM module
Normal
Test the resistance values among
Phases U, V and W of compressor
If the resistance
are equal and less
Check the installation condition
Disconnect the compressor harness connector from the outdoor unit PCB.
To disengage the connector, press the protrusion on the connector.
Then, to measure resistance between P (+) andN (-) and the U, V and W terminals of the
compressor connector with a multi-tester. Evaluate the measurement results for a pass/fail
judgment.
N(-)terminal of
tester)
P(+)terminal of
HSU12/18VHJ(DB)
The system leads to IPM protection due to over current
The compressor faulty leads to IPM protection
circuit component of IPM is broken and led to IPM protection
IPM protection dues to the compressor faulty
IPM protection dues to faulty PCB of IPM module
Compressor wiring disconnected
Be sure to turn off power switch before connect or disconnect connector,
else parts damage may be occurred.
NO
wiring
Yes
NO
Yes
Yes
.
tester(P(+)for digital
tester(N(-)for digital
Renewedly connect the wiring
Change the IPM module
NO
Replace the compressor
P(+) UVW
UVW P(+)
59
Functions and control
P(-) UVW
UVW P(-)
Domestic Air Conditioner
or