F13

Ground Fault

Allen-Bradley · PowerFlex 4M Adjustable Frequency

What does F13 mean?

This fault indicates that the drive has detected a leakage current path from one or more of its output terminals to earth ground. This typically points to a compromised insulation in the motor windings or the motor wiring, creating an unintended electrical path to ground. A ground fault is a serious safety concern, posing a risk of electric shock and potential damage to the motor or drive if not promptly addressed.

Common Causes

  • Motor winding insulation breakdown to the motor frame (earth ground).
  • Damage to the motor cable insulation (U, V, W) causing a short circuit to cable shielding or conduit.
  • Accumulation of moisture, oil, or conductive dust inside the motor terminal box or motor windings.
  • Short circuit between a motor phase and the drive's output ground (PE) terminal.
  • Improper or compromised grounding of the motor frame or cable shielding.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Disconnect all motor leads (U, V, W) from the drive output terminals.

  2. 2

    Power cycle the drive. If the fault clears with the motor disconnected, the fault is external to the drive (motor or cable).

  3. 3

    Using a megohmmeter (insulation tester), measure insulation resistance from each motor phase (U, V, W) to the motor frame ground. Expect >1MΩ.

  4. 4

    Visually inspect the motor cable for any signs of physical damage to the outer jacket or conductor insulation.

  5. 5

    Check the motor terminal box for moisture, condensation, or loose strands of wire causing a short to ground.

  6. 6

    Verify proper grounding of the motor frame to the common protective earth (PE) bus, and ensure cable shielding is correctly terminated.

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Verified technical data. Last updated: March 2026

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Source: Allen-Bradley PowerFlex 4M Adjustable Frequency