Load Short-circuit

What does SC mean?

This fault occurs when a short circuit is detected in the motor windings or the cabling between the inverter and the motor. It represents an immediate and severe electrical overload. The inverter quickly shuts down its output to prevent catastrophic damage to its power semiconductors (IGBTs) and potentially the motor.

Complete Troubleshooting Guide

1. 1

   Immediately remove power and disconnect the motor cables from the inverter.

2. 2

   Measure the resistance between each phase of the motor cables and also between phases and ground to check for shorts.

3. 3

   Perform a motor insulation resistance test (megger) between motor phases and motor frame.

4. 4

   If the motor is disconnected and the fault clears, the short is in the motor or motor cable; inspect for insulation damage.

5. 5

   Verify that the motor is rated correctly for the inverter and application, ensuring it is not undersized or damaged.