Output Short-Circuit or IGBT Fault

What does SC mean?

A short-circuit or ground fault is detected on the drive output side, which could be due to motor insulation damage, a shorted motor cable, or a hardware fault within the drive's output transistors (IGBTs). If unresolved, this fault can lead to significant damage to the drive's internal circuitry.

Complete Troubleshooting Guide

1. 1

   Check the motor insulation resistance using a megger; replace the motor if continuity is detected (expect >1 MΩ).

2. 2

   Inspect the motor power cable for damage, wear, or pinched sections, and repair any short-circuits or grounding issues.

3. 3

   Verify that the drive output is not shorted (e.g., B1 ←→ U, V, W or – (negative) ←→ U, V, W), as this will damage output transistors.

4. 4

   If a hardware fault within the drive is suspected after checking external components, contact your Yaskawa representative for assistance or replacement.