Power unit: Phase failure motor cable

What does F30015 mean?

This fault indicates a phase failure in the motor feeder cable. It can also occur if the motor stalls in U/f control, leading to zero current in one phase due to current asymmetry, or if closed-speed control is unstable, generating oscillating torque. Note that chassis power units do not monitor this condition. If left unresolved, this can lead to motor damage, drive instability, and unexpected shutdowns.

• Open circuit in one of the three motor output phases (U, V, or W) due to a loose terminal connection or broken cable strand.
• Motor winding fault (e.g., open phase, inter-turn short) causing a significant current imbalance or zero current in one phase.
• Failure of an external motor contactor or disconnect switch that interrupts only one phase of the motor supply.
• Operating in U/f control mode with a stalled motor, which can lead to zero current in one phase due to current asymmetry.

Click steps to track your progress.

1. 1

   Measure the resistance of each motor phase winding (U-V, V-W, W-U) at the drive's output terminals using a multimeter (power off).

2. 2

   Inspect all connections for the motor cable at the drive output terminals (U, V, W) and at the motor terminal box for tightness and corrosion.

3. 3

   Measure the current in each motor phase (r0027[0], r0027[1], r0027[2]) during operation to detect significant current imbalance.

4. 4

   Verify the operation of any external motor contactors, thermal overloads, or disconnect switches that are in the motor feeder circuit.

5. 5

   Ensure the motor control mode (P1300) is appropriate for the application and adjust P0604 (Current setpoint) if necessary.