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16.4.30. F99 (Output Over Current Detection)
Malfunction Decision Conditions
During operation of cooling and heating, when an output over-current (DC peak current value at IPM Prevention Control) is
detected by checking the current that flows in the inverter DC peak sensing circuitry.
Malfunction Caused
• Faulty outdoor unit PCB
• Faulty compressor
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 (-)
kΩ lareveSecnatsiser lamroN to several MΩ
ro 0ecnatsiser lamronbA