Output phase loss protection

What does E.LF mean?

This fault indicates a loss of one or more phases (U, V, W) on the inverter's output side, typically between the inverter and the motor. This protective function, which can be enabled by Pr. 251, stops the inverter output to prevent motor damage from unbalanced current flow. Operating a three-phase motor with a phase loss can severely overheat and damage the motor windings.

Complete Troubleshooting Guide

1. 1

   Inspect all power connections between the inverter output terminals (U, V, W) and the motor for loose or broken wires.

2. 2

   Use a multimeter to check the motor windings for an open circuit between phases.

3. 3

   Verify that Pr. 251 (Output phase loss protection selection) is set to '1' to enable this protective function.