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

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

What this means:
This error occurs when the DC bus voltage in the outdoor main control board rises above safe operating limits. The system stops to protect key components like the IPM module and power circuitTS23.

Try this first (quick reset):

1. Turn off power to the system.

2. Wait 2 minutes.

3. Turn the unit back on and observe the display.

• If the error clears — the issue may have been temporary.

• If it returns — continue with electrical diagnostics.

Next steps (for technicians):

1. Check power supply wiring:

   • Ensure the wiring of L and N terminals is correct.

   • Reconnect if loose or miswired.

2. Measure AC input voltage (L–N):

   • If abnormal → correct external power supply or wiring.

3. Measure input voltage to the bridge rectifier:

   • If abnormal → replace the bridge rectifier.

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

   • Use standard values from the troubleshooting guide.

5. Check PFC module and reactor wiring:

   • If loose → reconnect properly.

   • If faulty → replace the PFC module or reactor.

6. Check IPM module:

   • If the IPM is a standalone board and shows abnormal readings → replace it.

   • If built into the main PCB → replace the outdoor main PCB.

What you might need:

• Power supply wires

• Bridge rectifier

• PFC module or reactor

• IPM module board

• Outdoor main PCB

Helpful tip:
High bus voltage can often be traced back to power wiring issues or failed power correction modules. Always start with voltage testing before replacing hardware.

Click here to view the detailed guide.TS23