Ipm Protection - Haier HSU24VHG(DB)-G&W Service Manual

7.3.4 IPM protection

Outdoor display LED1 flash 2 times. Indoor Display F1
Method of IPM protection is detected by checking the compressor running condition and so on.
Malfunction
Detection
Malfunction The system leads to IPM protection due to over current.
Decision The compressor faulty leads to IPM protection.
Conditions Circuit component of IPM is broken and led to IPM protection.
Supposed IPM protection dues to the compressor faulty.
Causes IPM protection dues to faulty PCB of IPM module.
Compressor wiring disconnected.
Troubleshooting * Caution Be sure to turn off power switch before connect or disconnect connector, or
Turn off the power. check if
the compressor
connected ok or not
Check the IPM module
Normal?
Test the resistance values among
Phases U, V and W of compressor
If the resistance is 1Ω
or so
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, measure resistance between P (+) and N (-) 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
tester)
Normal resistance
Unacceptable resistance
else parts damage may be occurred.
NO
wiring
Yes
NO
Yes
Yes
Check the IPM module method:
tester(P(+)for digital
tester(N(-)for digital
Disconnect the wiring
Change the IPM module
NO
Replace the compressor
P(+) UVW
UVW P(+)
Several kΩ to several MΩ ( )
Short (0 Ω) or open
54
Service Diagnosis
P(-) UVW
UVW P(-)
Domestic Air Conditioner