Ground Fault

What does GF mean?

The ground fault detection circuit monitors output current and activates when one of the inverter output phases is connected to ground, or the grounding current exceeds 50% of the inverter rated current. This condition poses a serious electrical hazard, risks personnel safety, and can damage the inverter and connected motor if not resolved promptly.

Complete Troubleshooting Guide

1. 1

   Immediately disconnect power and visually inspect motor cables and windings for damage or signs of insulation breakdown.

2. 2

   Using a megger, measure insulation resistance between each motor phase and ground (motor frame) – expect >1 MΩ.

3. 3

   Disconnect the motor and run the inverter with no load; if the fault clears, the issue is likely with the motor or motor cabling.

4. 4

   Check for proper grounding of the inverter and motor according to installation guidelines.

5. 5

   Verify the integrity of the inverter's internal ground fault detection circuit (if diagnostic functions are available).