Panasonic WH-MHF09G3E5 Service Manual page 121

16.5.37 Outdoor Current Transformer Open Circuit (F46)
Malfunction Decision Conditions:
A current transformer (CT) open circuit is detected by checking the compressor running frequency (≥ rated
frequency) and CT detected input current (< 0.65A) for continuously 20 seconds.
Malfunction Caused:
1 CT defective.
2 Faulty outdoor unit PCB.
3 Compressor defective (low compression).
Abnormality Judgment:
Continue 3 times in 20 seconds.
Troubleshooting:
Operate heating operation.
When F46 occurs again, turn
OFF the power.
Check the 2/3 way valve.
Is the 2/3 way valve closed?
No
Check for gas leakage.
Is the oil oozing out from
the 2/3 way valve?
No
Turn ON the power, and
operate heating operation.
Yes
Open the 2/3 way valve.
- Replace the pipe flare or
Yes
union nuts.
- Reclaim and recharge
refrigerant.
For safety reason and to prevent component breakdown,
always switch off the power before remove and connect the component.
Measure the current from
the outdoor LIVE terminal.
Is the current < 0.65 A?
Yes
While the system is still in
heating operation, check the
discharge pressure.
Is the pressure unchanged (same
as when compressor stop)?
Yes
While the system is still in heating operation,
further check (by touching) if;
- Compressor discharge pipe is cold.
- Compressor body is warm to confirm the
compressor low compression.
Yes
121
- Defect in CT.
No
- Replace the outdoor
unit PCB (main).
No
Replace the outdoor unit
PCB (main).
Replace the compressor.