ALARM 4

Mains phase loss

Danfoss · VLT HVAC Drive High Power

What does ALARM 4 mean?

A phase is missing on the supply side, or the mains voltage imbalance is too high. This message also appears for a fault in the input rectifier. Options for handling this are programmed in parameter 14-12 Function at Mains Imbalance. Operating with a missing phase can severely damage the motor or the frequency converter.

Complete Troubleshooting Guide

  1. 1

    Check the supply voltage to the frequency converter.

  2. 2

    Check the supply currents drawn by the frequency converter.

Source: Danfoss Manual