26
6 --- IPM malfunction or IGBT over---strong current protection --- diagnosis and solution (P0)
Error Code
P0
Malfunction conditions
When the voltage signal that IPM sends to compressor drive chip is abnormal, the display LED will
shows “P0” and the system will turn off.
Possible Causes
• Wiring mistake
• IPM malfunction
• Defective outdoor fan assembly
• Compressor malfunction; Outdoor PCB faulty
Trouble shooting:
Is the wiring between main PCB
and compressor connected incorrectly?
Are wires and connectors broken?
Correct the connection or replace
the wires and connectors.
Yes
No
IPM continuity check. Check if the
IPM terminal resistance values are
uniform.
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
Refer to the Notes below, 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 .
No
Replace the compressor.
Yes
Replace the outdoor main PCB if the
main PCB and IPM are separate.
A14486
Note:
Measure the black pin and red pin of the motor terminals, the resistance should be around the value specified below:
Model size
Voltage
Resistance Value at
68
_
F(20
_
FC)
9K and 12K
115
50
Ω
12K
208-230
293
Ω
18K AC / 17K HP
84.5
Ω
22K
88.5
Ω
