Output Phase Supervision

What does 11 mean?

This fault indicates that the drive's current measurement system has detected zero current in one of the motor phases. This typically points to a disconnection or malfunction in the motor or its cabling, or an issue with an associated du/dt or sinus filter. Continued operation with a missing phase can lead to motor damage or reduced performance.

• Open circuit in one of the motor output phases (U, V, or W) between the AC drive and the motor, typically due to a loose terminal connection or broken cable.
• Internal winding failure (e.g., open circuit) within the connected motor, preventing current flow through one phase.
• Faulty motor contactor or motor starter bypassing a phase, not allowing current to flow to the motor.
• Incorrectly sized or blown fuse in one of the motor output phases (if applicable, though less common directly from drive output).
• Malfunctioning current sensor or current measurement circuit within the AC drive itself, providing a false zero current reading for a phase.

Click steps to track your progress.

1. 1

   1. With power off and safety measures applied, measure resistance between drive output terminals (U-V, V-W, W-U) and compare to expected motor winding resistance.

2. 2

   2. Disconnect motor power cables at the drive output terminals (T1, T2, T3) and perform a continuity test on each cable phase from the drive to the motor.

3. 3

   3. Perform a winding resistance test on the motor itself by measuring resistance between U, V, and W terminals at the motor side, expecting balanced readings.

4. 4

   4. Verify all terminal connections at the drive output (U, V, W) and the motor input for tightness and proper seating.

5. 5

   5. If an output choke or filter is installed, inspect its connections and internal continuity across each phase.