1. CT circuit failure (including cut wiring, etc.)
2. Disconnected CT circuit connector
3. Missing phase where CT circuit is connected
4. This CT circuit is connected to the connector of the other CT circuit.
5. PCB failure
6. Electrical noise

1. CT circuit failure, PCB failure

Trouble: Current value during compressor operation is below the threshold value.

Check:
• Check that the connector is not disconnected
• Check the continuity of the CT circuit.
• Install a normal CT in place of this CT and check. If current is detected, then the PCB can be judged OK.
→ CT circuit failure
• Check that current is flowing in the phase where the CT circuit is connected. Check voltage and current.

2. Crossed wiring or installation error

Trouble: When the compressor is stopped, the current value at the other compressor is high.
☆ When this type of condition occurs, seizing-detection control takes priority.

3. If the cause is still unknown after checking the above, then it is possible that noise is the cause of the trouble. It is necessary to connect a PC or other instrument.

1. Replace the CT circuit.
2. Replace the outdoor unit PCB.
3. Correct the problem.

1. The connector was not inserted after the PCB was replaced.