DC Bus Overvoltage

What does OU mean?

The DC bus voltage has exceeded its safe operating limit, primarily caused by an excessively high incoming mains voltage. This fault can also be triggered by regenerative energy from the motor if deceleration times are too short or the brake resistor is undersized/missing. Overvoltage poses a significant risk of damage to the drive's internal components, especially the DC bus capacitors and power semiconductors.

Complete Troubleshooting Guide

1. 1

   Verify the incoming mains voltage meets the controller's specifications and is not consistently high.

2. 2

   Check the DC bus voltage during operation to identify if regenerative energy is causing the overvoltage.

3. 3

   If applicable, increase deceleration times or verify the external brake resistor for proper dimensioning and connection.