Panasonic CS-HE9JKE Service Manual page 73

15.4.25. F99 (Output Over Current Detection)
Malfunction Decision Conditions
During operation of cooling and heating, when an output over-current (20.2A) 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
20.2A?
• 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
Tester's positive terminal
N r o m l a e r s s i a t n c e
A b n r o m l a e r s s i a t n c e
Power transistor (+)
UVW Power transistor (+)
UVW Power transistor (-)
UVW
S e v e a r k l to several M
0 r o
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UVW
Power transistor (-)