277
25.2.30 Output Over Current Detection (F99 / P16 / F23)
Malfunction Decision Conditions:
During operation of cooling and heating, when outdoor DC current is above set valve is detected by the IPM DC
Peak sensing circuitry in the outdoor unit PCB (main).
Malfunction Caused:
1. Faulty outdoor unit PCB (main).
2. Faulty compressor.
Abnormality Judgment:
Continue for 7 times.
Troubleshooting:
For safety reason and to prevent component breakdown,
always switch off the power before remove and connect the component.
Check the compressor winding resistance:
- Turn OFF the power and disconnect the
harnesses U, V, and W.
- Measure the winding resistance between
U-V, V-W, and W-U.
Are the compressor’s
winding resistance (U-V, V-
W, or U-W) shorted?
- Compressor defective due to
winding shorted.
- Replace the compressor.
- Outdoor eletronic circuit
defect due to power transistor
shorted.
- Replace the outdoor unit
PCB (main).
Checking the power transistor
Never touch any live parts for at least 10 minutes after turning off the circuit breaker.
If unavoidably necessary touch a live part, make sure the power transistor’s supply
voltage is below 50 V using the tester.
For the UVW, make measurements at the Faston terminal on the board or the relay
connector.
Tester’s negative terminal
Several kohms to several Mohms
Power transistor
(+)
Power transistor
(+)
Power transistor
(-)
Power transistor
(-)
UVW
UVW
UVW
UVW
Tester’s positive terminal
Normal resistance
Abnormal resistance
0 or ∞
Yes
No
Caution
