Applicable Systems
SK
Symptoms
The SK reports an inverter stage fault. The output inverter section detected a fault in the IGBT power switching circuit.
Possible Causes
- IGBT module failure or degradation
- Gate drive circuit fault preventing proper IGBT switching
- DC bus capacitor degradation causing excessive ripple current
Troubleshooting Steps
- Step 1: Check the IGBT module for short circuit between collector and emitter
IGBT shows no short circuit - Step 2: Verify the gate drive signal with an oscilloscope
Gate drive signal has correct amplitude and timing - Step 3: If the IGBT is faulty, replace the drive unit
New unit operates with healthy IGBT modules
How to Reset
To reset: Fix the inverter fault or replace the unit, then restart.
Source: NORD SK Drive System Manual, NORD Drives
Category: PLC & VFD