F40

Phase W to Gnd

Allen-Bradley · PowerFlex 4 Adjustable Frequency AC Drive

What does F40 mean?

A grounded phase condition has been detected specifically on motor phase W or in the wiring connecting drive output terminal W to the motor. This indicates a direct short path to ground.

Additional Steps

Steps 1–2 are listed in Priority Fix.

  1. 3

    Measure insulation resistance between motor phase W and the motor frame using a megger at 500VDC; expect a reading greater than 1 MΩ.

  2. 4

    Inspect the wiring connecting drive output terminal W and motor phase W for any physical damage or signs of insulation breakdown.

Source: Allen-Bradley PowerFlex 4 Adjustable Frequency AC Drive
Open Manual (Page 15)