Allen-Bradley · PowerFlex 520-series Adjustable Frequency
This fault signifies an unintended current path from the motor or drive output system to ground. It typically occurs during motor acceleration or deceleration and can pose a significant safety risk, lead to equipment damage, or cause electrical interference if not promptly addressed. This indicates a breakdown in insulation.
Click steps to track your progress.
Disconnect the motor cables (U, V, W) from the drive output and measure insulation resistance (Megger) from each motor phase to motor ground, verifying it exceeds 1 Megohm.
With motor cables disconnected from the drive, measure insulation resistance (Megger) from each drive output terminal (U, V, W) to the drive chassis ground (PE terminal) to isolate the fault source.
Visually inspect the entire length of the motor cable for any visible damage, chafing, signs of water ingress, or improper termination.
Inspect the motor terminal box for moisture, corrosion, or loose connections that could create a ground path.
Check the grounding integrity of the motor frame and the drive chassis to the main earth ground (PE terminal), ensuring resistance is below 0.1 Ohm.