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.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

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