Error Code: PC 10 – Outdoor Unit Low AC Voltage Protection

Error Code: PC 10 – Outdoor Unit Low AC Voltage Protection

What this means:
This protection is triggered when the AC voltage supplied to the outdoor unit drops below the acceptable range. The system shuts down to prevent damage to the inverter circuitry and power moduleTS23.

Try this first (quick reset):

1. Power off the system.

2. Wait at least 2 minutes.

3. Power back on and check if the voltage has normalized and the error clears.

• If the error clears — the voltage likely returned to normal.

• If not — continue with voltage and board checks.

Next steps (for technicians):

1. Check the AC input voltage (L–N):

   • If abnormal → correct the external power supply issue.

   • If normal → continue.

2. Check the wiring of power cables, L and N terminals:

   • If loose or misconnected → reconnect correctly.

3. Measure voltage at the bridge rectifier input:

   • If voltage is low or unstable → replace the bridge rectifier.

4. Measure the voltage between P and N terminals (DC bus):

   • Refer to standard ranges from the manual.

   • If abnormal → check the reactor or inductance module.

5. Check the wiring and resistance of the reactor:

   • If loose → reconnect properly.

   • If faulty → replace the reactor or inductance coil.

6. Check the IPM module board:

   • If built-in with the PCB → replace the entire outdoor main PCB.

What you might need:

• Outdoor PCB

• Power supply wires

• Bridge rectifier

• Reactor or inductance coil

• IPM module board

• Multimeter for voltage testing

Helpful tip:
Voltage issues are often caused by poor connections or unstable mains power. Check all terminals and wiring before replacing expensive components.

Click here to view the detailed guide.TS23