Error Code: PC 11 – Outdoor Main Board DC Bus High Voltage Protection

Error Code: PC 11 – Outdoor Main Board DC Bus High Voltage Protection

What this means:
The outdoor unit has detected that the DC bus voltage on the main control board is too high. This protection prevents damage to the inverter and other components by shutting the system down when overvoltage occurs.

Try this first (quick reset):

1. Turn off the unit completely.

2. Wait 2 full minutes.

3. Turn the unit back on and check if the error clears.

• If the error disappears — the overvoltage may have been temporary.

• If it returns — continue with the troubleshooting steps below.

Next steps (for technicians):

1. Check the power supply:

   • Verify that incoming AC voltage is within the normal operating range (typically 220–400V).

   • If the voltage is too high, wait until it stabilizes or consult an electrician.

2. Inspect wiring and connections:

   • Ensure all wiring is securely connected and undamaged.

   • Replace any loose or corroded power supply wires.

3. Measure voltage between P and N terminals:

   • In standby mode, DC voltage should read around 310V, 340V, or 380V (model-dependent).

   • If voltage is higher than expected, this confirms the overvoltage issue.

4. Component testing and replacement:

   • If overvoltage persists:

     • Replace the IPM module board.

     • If the issue remains, inspect and possibly replace the reactor.

     • If the reactor is normal and error persists, replace the outdoor PCB.

What you might need:

• IPM module board

• Outdoor PCB

• Reactor

• Power supply wires

Helpful tip:
DC bus overvoltage is often caused by power supply fluctuations, faulty reactors, or internal PCB failures. Always measure DC voltage under standby and load conditions before replacing components.

Click here to view the detailed guide.TS10-S