Output Ground Fault

What does GF mean?

A GF fault occurs when the current to ground on the output side of the drive exceeds 50% of the drive’s rated output current. This is determined by comparing the measured current on each of the output phases, indicating a leakage path from the motor or its associated output cabling to ground. This is a serious fault that poses a significant safety hazard and can lead to severe damage to the drive, motor, or other connected equipment if not immediately addressed.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Check for contamination, debris, or moisture in the motor terminal box, drive output terminals, and junction boxes along the cable path.

2. 4

   Ensure proper grounding practices for the motor, output cables, and the drive enclosure, verifying all earth connections are secure.

3. 5

   If the fault persists after checking external components, the drive itself might have an internal ground fault, requiring professional service or replacement.