Phase U to Gnd

What does F38 mean?

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

• Phase U winding shorted to ground in the motor.
• Cable insulation failure between phase U and ground.
• Internal drive fault with phase U output stage.
• Grounding fault on phase U line conductor.

Click steps to track your progress.

1. 1

   Disconnect the motor from the drive output terminals (U, V, W).

2. 2

   Measure insulation resistance between drive output terminal U and earth ground using a megger at 500VDC; expect a reading greater than 1 MΩ.

3. 3

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

4. 4

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