Output Ph Loss

What does F021 mean?

One or more of the output phases (U, V, W) to the motor has been lost or is significantly unbalanced, if this function is enabled (A557 [Out Phas Loss En]). This condition can lead to severe motor overheating, vibration, and damage if the motor continues to operate on reduced phases.

Complete Troubleshooting Guide

1. 1

   Verify all motor wiring connections at both the drive output terminals and the motor terminal box for tightness and continuity.

2. 2

   Measure the resistance of each motor winding to ensure they are balanced and not open-circuited.

3. 3

   Inspect the motor for any internal damage that could lead to an open winding or phase imbalance.

4. 4

   Check for any external devices (e.g., motor contactors, disconnects) between the drive and motor that may have failed or opened a phase.