F041

Phase UV Short

Allen-Bradley · PowerFlex 520-series Adjustable Frequency

What does F041 mean?

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.

Common Causes

  • Short circuit between U-phase and V-phase conductors within the motor power cable due to insulation damage (e.g., pinching, abrasion).
  • Internal short circuit between U and V windings inside the motor, often caused by insulation breakdown from overheating or mechanical stress.
  • Contamination (e.g., metal shavings, carbon dust) bridging the U-phase and V-phase terminals in the motor junction box or drive output.
  • Incorrect wiring or loose terminals allowing U and V phases to come into direct contact within the motor terminal box.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Disconnect the motor leads (U, V, W) from the drive output terminals (T1, T2, T3).

  2. 2

    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.

  3. 3

    Visually inspect the motor cable for physical damage, especially near cable entries, bends, or glands.

  4. 4

    Inspect the motor terminal box for any signs of arcing, burnt insulation, or foreign conductive material between U and V terminals.

  5. 5

    If the motor cable is suspected, disconnect the cable from the motor and measure resistance between U and V conductors at the drive end.

  6. 6

    If the motor windings are shorted, schedule motor removal for repair or replacement.

Browse all codes in this manual (48)
Verified technical data. Last updated: March 2026

Related Faults

Source: Allen-Bradley PowerFlex 520-series Adjustable Frequency