ALARM 30

Motor phase U missing

Danfoss · VLT HVAC Drive High Power

What does ALARM 30 mean?

Motor phase U between the frequency converter and the motor is missing. This indicates a loss of one of the three phases supplying the motor, which can lead to motor damage or failure if operated in this state.

Complete Troubleshooting Guide

  1. 1

    Remove power from the frequency converter.

  2. 2

    Check motor phase U connections and wiring.

Source: Danfoss Manual