Common causes of overcurrent in inverters

During the use of inverters, the proportion of inverter overcurrent faults accounts for about 40%-45% of the total inverter faults, which is a high-incidence fault of inverters. The overcurrent phenomena include: short circuit fault, acceleration/deceleration overcurrent, and constant speed overcurrent.

Common overcurrent phenomena and causes of inverters are as follows:

1. Overcurrent fault is reported when power is turned on.

Most of this situation cannot be reset. The main reasons for this situation are: IGBT/IPM module damage, abnormal drive signal, current detection circuit failure, etc. In this case, the inverter must be repaired in time to avoid the expansion of the fault.

2. The inverter displays normally when it is powered on and in standby, but reports an overcurrent fault as soon as it is running.

The main reason for this situation is that the load motor and mechanical transmission mechanism are blocked. In this case, it is strictly forbidden to use the inverter to test the machine back and forth without eliminating the problem.

3. The inverter is normal at the beginning of startup, but reports overcurrent during acceleration.

The main reasons are that the inverter acceleration time is set too short, the motor rated current value is set smaller than the actual value, and the torque compensation (U/F) parameter is set too high.

When using the inverter, the user can determine the cause of the overcurrent based on the inverter overcurrent phenomenon and take targeted maintenance measures.