Error 4220 (Detail 108) – Abnormal bus voltage drop detected

What does 4220 (D108) mean?

A DC bus voltage of 200V or less is detected during inverter operation. This can be caused by power supply environment issues, a voltage drop within the system, or faults in the noise filter or INV board.

• Power supply environment (e.g., instantaneous stop, power failure)
• Voltage drop detected
• Noise filter board fault
• INV (Inverter) board failure

Click steps to track your progress.

1. 1

   Check the interphase power supply voltage to ensure it is 198V or above.

2. 2

   Observe the bus voltage on the LED monitor during inverter operation.

3. 3

   Check the wiring connections between the INV board, control board (CN631), ACL, noise filter board, and power supply terminal block (TB2).

4. 4

   Inspect coils (L1-L3) for breakage and verify their resistance (20 Ω ± 5%).

5. 5

   If the voltage across pins 1-3 of CN631 on the control board is 200V or above but the bus voltage is low, the control board may need replacement; otherwise, the INV board may be faulty.