OC1 Overcurrent in motor cable

What does 0011 mean?

An overcurrent (Ia > 2.25 x IN) has occurred in the motor cable, detected by hardware monitoring. This can be caused by a short circuit in the motor cable, excessive capacitive charging current of the motor cable, or acceleration/deceleration times that are too short for the load. It can also indicate a missing mains phase or an encoder wiring issue.

• Short circuit between two motor phase conductors (U, V, or W) due to insulation damage or mechanical stress on the motor cable.
• Short circuit from a motor phase conductor (U, V, or W) to the motor frame or earth due to compromised cable insulation.
• Incorrect motor cable length or type for the drive, leading to excessive capacitive charging current (especially with unshielded cables).
• Motor cable conductors (e.g., U1, V1, W1) shorted at the motor terminal block or drive output terminals (e.g., X2/U, X2/V, X2/W).

Click steps to track your progress.

1. 1

   Power down the drive and disconnect the motor cable from the drive's output terminals (e.g., X2/U, X2/V, X2/W).

2. 2

   Measure insulation resistance between each motor phase conductor (U, V, W) and between each phase and ground using a megohmmeter (e.g., 1000VDC test voltage).

3. 3

   Measure the resistance between each pair of motor phase conductors (U-V, V-W, W-U) using a multimeter to check for short circuits.

4. 4

   Visually inspect the entire length of the motor cable for cuts, abrasions, or crushed sections, especially at bend points and cable glands.

5. 5

   Verify the motor cable length and type against drive specifications for maximum allowable capacitive current (refer to drive manual).

6. 6

   Inspect motor terminal block connections for proper torque and absence of stray wire strands that could cause a short circuit.