Motor phase W missing

What does #32 mean?

This fault indicates that the W phase supply to the motor is not being detected by the drive. This condition prevents the motor from starting or running properly, and continued operation could lead to motor damage due to unbalanced phases or a complete system shutdown.

• Open circuit in the motor cable (e.g., conductor break, loose terminal connection) for phase W between the drive and the motor.
• Motor winding open circuit (e.g., coil failure) specific to the W phase within the motor itself.
• Faulty motor contactor (e.g., main contactor KM1) pole for phase W failing to close or making intermittent contact.
• Internal power component failure (e.g., IGBT, phase current sensor) on the W phase output stage of the variable frequency drive (VFD).
• High resistance connection at the motor terminal block or drive output terminal for phase W, causing a voltage drop detectable by the drive.

Click steps to track your progress.

1. 1

   Isolate power, then measure resistance between drive output terminal W (e.g., T3) and motor terminal W to verify cable continuity.

2. 2

   Disconnect motor cables from the motor, then measure motor winding resistance between phase W and phase U, and phase W and phase V; compare values (e.g., within 5% tolerance).

3. 3

   Verify proper contact engagement of main contactor (e.g., KM1) poles for phase W using a multimeter in continuity mode (power isolated).

4. 4

   Check for loose connections at the drive's output terminals (e.g., U, V, W) and the motor's terminal box for phase W.

5. 5

   With power isolated and DC bus discharged, inspect drive output terminals and busbar connections for phase W for signs of arcing or overheating.