Overcurrent in phase B

What does 4635 mean?

An overcurrent condition has been detected or reported in phase B of the drive or terminal. This indicates that the current flowing through phase B has exceeded the drive's or motor's rated capacity. Potential causes include mechanical overload, a short circuit in the motor or cable, or incorrect motor parameters in the drive, risking damage to the drive and motor.

• Short circuit or ground fault in the motor power cable for phase B between the drive output (V) and the motor terminal.
• Motor winding short to ground or turn-to-turn short in phase B of the motor.
• Mechanical overload on the motor causing excessive current draw (e.g., brake not fully releasing), exceeding the drive's current limit (P1-54, Motor rated torque, exceeded).
• Incorrect motor parameters configured in the drive (e.g., P1-03, Motor rated current, set too low), leading to premature trip.
• Faulty IGBT or power stage component in phase B of the drive output stage.

Click steps to track your progress.

1. 1

   Power down the drive and motor, then disconnect the motor cable from the drive output terminals (U, V, W).

2. 2

   Measure the insulation resistance from each motor output terminal (U, V, W) to ground using a megohmmeter (e.g., 500VDC test voltage); readings below 1MOhm indicate a ground fault.

3. 3

   With the motor cable disconnected, slowly ramp up the drive (without motor) to verify if the overcurrent fault persists, indicating a drive internal fault.

4. 4

   Verify the motor rated current (P1-03) and motor nominal voltage (P1-02) parameters in the drive are correctly configured to match the motor's nameplate data.

5. 5

   Inspect the mechanical system driven by the motor for any binding, excessive friction, or blockages that could lead to torque overload (Measure starting torque with a torque wrench if possible).

6. 6

   Measure the resistance between phases (U-V, V-W, W-U) at the motor terminals; significant imbalance (e.g., >5%) or a very low reading on one phase indicates an internal motor winding fault.