Output Phase Loss

What does LF mean?

This fault occurs when one of the inverter's output phases to the motor is lost, typically detected if the RMS current value for a phase drops below a detection level for 10 seconds. This indicates a potential disconnection, break in motor wiring, or a fuse blown on one phase. Operating with phase loss can lead to motor overheating, vibration, and uneven wear, severely damaging the motor.

Complete Troubleshooting Guide

1. 1

   Immediately power down and inspect all connections between the inverter output terminals and the motor terminals.

2. 2

   Check motor cables for continuity and signs of physical damage or insulation failure.

3. 3

   Measure the resistance of each motor winding to ensure they are balanced and continuous.

4. 4

   Verify that the output phase loss protection (L8-07) is enabled and set appropriately for the application.

5. 5

   If contactors are present between the inverter and motor, check their contacts for pitting or failure.