Earth (ground) fault

What does 14 mean?

There is an undesirable current path from one or more output phases to earth, either in the cable connecting the frequency converter to the motor or within the motor itself. This fault indicates a serious insulation breakdown, posing a safety risk and potential for severe equipment damage if power is not immediately removed.

• Insulation breakdown in one or more motor output phases (U, V, W) to the motor frame or ground.
• Damaged motor cable insulation creating a short circuit path from a phase conductor to the cable shield or conduit.
• Moisture ingress or contamination within the motor or motor terminal box leading to a conductive path to ground.
• Incorrect grounding of the motor, frequency converter, or cable shield causing a ground loop or improper current path.

Click steps to track your progress.

1. 1

   Disconnect the motor cables from the drive output terminals (U, V, W). Perform an insulation resistance test (Megger) from each motor phase to ground on the motor side.

2. 2

   Visually inspect the entire motor cable run from the drive to the motor for signs of physical damage, chafing, or moisture ingress.

3. 3

   Use a multimeter to check for continuity between each motor output phase (U, V, W) and the ground terminal on the motor side; resistance should be infinite.

4. 4

   Verify proper grounding connections of the motor frame, frequency converter chassis, and cable shield according to installation guidelines.