DC-Bus Undervoltage

What does LU mean?

The DC-bus voltage in the drive has fallen below the acceptable operating threshold. This is typically caused by insufficient or unstable mains voltage supplied to the drive, or a fault within the supply module. Low DC-bus voltage prevents the drive from delivering adequate power to the motor and can lead to erratic operation or shutdown.

Complete Troubleshooting Guide

1. 1

   Measure and verify the incoming mains voltage to ensure it is within the specified range for the drive.

2. 2

   Inspect the supply module for any signs of malfunction, damage, or incorrect wiring.

3. 3

   Check all power connections from the mains to the drive for looseness or corrosion.