OC1

What does 011 mean?

A short circuit has occurred in the motor cable, or there is excessive capacitive charging current if the motor cable is too long or has high capacitance. This can lead to drive tripping and potential damage.

• Motor cable short circuit: Insulation breakdown between motor phases (U, V, W) or between a phase and ground (PE) within the motor cable.
• Excessive cable capacitance: The motor cable length exceeds the drive's specified maximum (e.g., P2-11 for max cable length), leading to high capacitive charging currents at switching frequencies.
• Motor winding short: An internal short circuit between phases or to the motor frame within the motor windings themselves.
• Inverter output component failure: A short circuit within the drive's output stage (e.g., IGBT failure) leading to excessive current flow.
• Ground fault: A direct ground fault from a motor phase to the machine's protective earth (PE) due to insulation damage.

Click steps to track your progress.

1. 1

   Disconnect the motor cable from the drive's output terminals (U, V, W) and from the motor. Using a megohmmeter (insulation tester), measure the insulation resistance between each motor phase conductor and ground (PE), and between each phase conductor (e.g., U to V, V to W, W to U); readings should be >1 M Ohm.

2. 2

   With the motor cable disconnected from both ends, measure the capacitance of each phase conductor to ground using a multimeter with capacitance function; compare against manufacturer's specifications for max cable length (e.g., based on P2-11).

3. 3

   If the motor cable tests clear, reconnect it to the drive. Disconnect the motor from the cable. Test the motor's windings for short circuits or ground faults using a megohmmeter (e.g., between motor terminals U, V, W and motor frame).

4. 4

   Verify the motor current limit parameter (e.g., P2-01 or P2-02 for overcurrent trip level) is correctly set based on the motor's rated current and not excessively low.

5. 5

   If all external components test good, connect a smaller, known-good test motor (if available) to the drive to determine if the drive's output stage is faulty.