VFD Keeps Tripping — Overcurrent, Ground Fault, Bus Faults
A drive that trips at power-up usually has a failed input stage or shorted IGBT. A drive that trips under load usually has aged DC-bus capacitors or a failing power stage. Both repair well below replacement cost — and repair beats the multi-week lead time on many replacement drives.
What's usually behind it
Shorted IGBT output stage
The most common hard failure. Often announced by an overcurrent or ground-fault trip the moment the drive tries to run. Replaced with new modules and load-tested.
DC bus capacitor aging
Capacitors are the VFD's wear item. Undervoltage trips, ride-through failures, and audible hum precede failure. Full bus recap is routine in our repairs.
Precharge circuit failure
A failed precharge resistor or relay causes bus faults at power-up and can destroy the rectifier if ignored.
Cooling failure
Dead fans and clogged heatsinks cause overtemperature trips and cook the power stage over time. Fans are replaced as standard in our drive repairs.
Repairs that fix this
Allen-Bradley
Free evaluationPowerFlex VFD Repair
PowerFlex drives up to 25 HP — free evaluation, typical repairs $350–$900 against four-figure replacements.
3–5 business days in lab · Free evaluation →
Multi-brand
Free evaluationVFD Repair (ABB, Yaskawa, Danfoss & More)
Most major-brand VFDs up to 25 HP — free evaluation, typical repairs $300–$900.
3–5 business days in lab · Free evaluation →
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