Panasonic WH-UD28AE Service Manual page 66

16.5.24. Output Over Current Detection (F99)
Malfunction Decision Conditions:
During operation of heating, outdoor current above 30.0 ± 5.0 A is detected by the IPM DC Peak sensing circuitry.
Malfunction Caused:
1. DC peak due to compressor failure.
2. DC peak due to defective power transistor(s).
3. DC peak due to defective outdoor unit PCB.
Abnormality Judgment:
Continue for 7 times.
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