Short-Circuit / Excessive Capacitive Charging Current

What does OC1 mean?

A short-circuit condition or an excessive capacitive charging current in the motor cable has been detected. The former can be due to damaged wiring or motor faults, while the latter can occur with very long or high-capacitance motor cables, causing the drive to trip due to high initial currents. This can lead to nuisance tripping, operational instability, and severe damage to the inverter output stage if a true short circuit is present.

Complete Troubleshooting Guide

1. 1

   Immediately power down the drive and physically inspect all motor cables for signs of damage, insulation breakdown, or contact between conductors.

2. 2

   Perform an insulation resistance test (megger test) on the motor windings and cables to ground, and between phases, to identify the short-circuit location.

3. 3

   If using long motor cables, consider shortening them or replacing them with low-capacitance motor cables suitable for inverter duty.