Allen-Bradley · PowerFlex 4M Adjustable Frequency
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.
Click steps to track your progress.
Disconnect all motor leads (U, V, W) from the drive output terminals.
Power cycle the drive. If the fault clears with the motor disconnected, the fault is external to the drive (motor or cable).
Using a megohmmeter (insulation tester), measure insulation resistance from each motor phase (U, V, W) to the motor frame ground. Expect >1MΩ.
Visually inspect the motor cable for any signs of physical damage to the outer jacket or conductor insulation.
Check the motor terminal box for moisture, condensation, or loose strands of wire causing a short to ground.
Verify proper grounding of the motor frame to the common protective earth (PE) bus, and ensure cable shielding is correctly terminated.