DC Bus Undervoltage

What does UV1 mean?

The DC bus voltage fell below its trip point (≤190Vdc for 208-240Vac Drives; ≤380Vdc for 480Vac Drives). This is often due to low input voltage at the R/L1, S/L2, and T/L3 terminals, an acceleration time set too short, or excessive input voltage fluctuations, risking drive instability or shutdown.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Monitor the input voltage for large fluctuations and address any power supply instability issues.