Undervoltage Alarm

What does UV mean?

An Undervoltage (UV) alarm is displayed on the digital operator during a momentary power loss event, specifically after power loss but before a fault trip occurs. This indicates that the drive is actively attempting to ride through the power loss, maintaining operation as long as control power is sustained. It's a warning, not a fault that stops the drive immediately.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Confirm that the external run command is continuously held during the power loss event if ride-thru operation is expected.

2. 4

   Assess if the control power supply duration is sufficient for the application's required ride-thru time; larger drives generally sustain control power longer.