Panasonic CS-NE9NKE, Service Manual, Page: 88 / 117

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15.4.30 F99 (Output Over Current Detection)
Malfunction Decision Conditions
•
During operation of cooling and heating, when an output over-current (18.5A) is detected by checking the current
that flows in the inverter DC peak sensing circuitry.
Malfunction Caused
•
DC peak due to compressor failure.
•
DC peak due to defective power transistor(s).
•
DC peak due to defective outdoor unit PCB.
Troubleshooting
•
Checking the power transistor
•
Never touch any live parts for at least 10 minutes after turning off the circuit breaker.
•
If unavoidable necessary to touch a live part, make sure the power transistor’s supply voltage is below 50V using
the tester.
•
For the UVW, make measurement at the Faston terminal on the board of the relay connector.
Tester’s negative terminal Power transistor (+) UVW Power transistor (-) UVW
Tester’s positive terminal UVW Power transistor (+) UVW Power transistor (-)
Normal resistance Several k Ω to several M Ω
Abnormal resistance 0 or ∞