Allen-Bradley · PowerFlex 520-series Adjustable Frequency
Excessive current has been detected between the drive's U and V output terminals, indicating a short circuit. This could be a phase-to-phase short in the motor windings or within the cables connecting the drive to the motor. This is a critical fault that can cause severe damage to the drive's output power stage (IGBTs) if not immediately addressed.
Click steps to track your progress.
Disconnect the motor leads (U, V, W) from the drive output terminals (T1, T2, T3).
Measure the resistance between the U-phase and V-phase motor leads using a multimeter. A reading significantly below the expected winding resistance indicates a short.
Visually inspect the motor cable for physical damage, especially near cable entries, bends, or glands.
Inspect the motor terminal box for any signs of arcing, burnt insulation, or foreign conductive material between U and V terminals.
If the motor cable is suspected, disconnect the cable from the motor and measure resistance between U and V conductors at the drive end.
If the motor windings are shorted, schedule motor removal for repair or replacement.