Earth (ground) fault

What does 14 mean?

A discharge of current from one or more output phases to ground has been detected, indicating an insulation breakdown. This fault can occur either in the motor cables connecting the drive to the motor or within the motor windings themselves. This is a critical safety fault posing an electrical shock hazard and potentially leading to severe damage to the frequency converter and motor if not promptly addressed.

• Degradation or damage to motor cable insulation (e.g., cuts, abrasions, moisture ingress) causing current leakage to ground.
• Moisture, condensation, or conductive contamination within the motor terminal box.
• Motor winding insulation breakdown, resulting in a direct phase-to-ground fault within the motor.
• Improperly terminated cable shields or unshielded motor cables in high noise environments.
• Loose or corroded ground connection for the motor frame or cable shields.

Click steps to track your progress.

1. 1

   Power off the drive. Disconnect motor cables from drive output terminals (U, V, W). Perform an insulation resistance test (megger) from each motor cable conductor to ground (PE).

2. 2

   Perform an insulation resistance test (megger) from each motor winding terminal (U, V, W) to the motor frame (PE) at the motor terminal box.

3. 3

   Visually inspect the motor terminal box for moisture, corrosion, carbon tracking, or loose wire connections.

4. 4

   Verify proper grounding and shielding of the motor cables according to manufacturer guidelines and electrical codes.

5. 5

   Check continuity of the protective earth (PE) connection from the motor frame to the drive's PE terminal.