Drive cooling fan
Common heat-related VFD and servo-drive failure point.
VFD Trip Reset Guide: How to Clear Fault Codes Safely
Resetting a VFD trip is easy. Resetting it safely is the real job. Overcurrent, ground fault, overvoltage, undervoltage, overtemperature, and communication faults all clear in slightly different ways, but the rule is the same: identify whether the trip was caused by the load, the motor, the power source, the setup, or the drive itself before you hammer the reset button.
Common VFD Trip Types
| Symptom / Code | Common Meaning | Typical Brands |
|---|---|---|
| Overcurrent | Load jam, short ramp, or output short | ABB, Yaskawa, Allen-Bradley, Danfoss |
| Ground fault | Motor or cable insulation leak | All major VFDs |
| Overvoltage | Fast decel or regenerative load | All major VFDs |
| Undervoltage | Low line voltage or phase loss | All major VFDs |
| Overtemp | Cooling failure or overloaded drive | All major VFDs |
| Communication | PLC / keypad / fieldbus loss | Networked systems |
When a simple reset is fine
A nuisance communication glitch or a known utility sag may clear cleanly once. Even then, it is worth checking logs before resuming full production.
When not to reset blindly
Ground fault, repeated hardware overcurrent, and short-circuit style trips should not be reset repeatedly. Those are the faults that destroy replacement drives if the motor or cable is bad.
Best practice sequence
Read the code, review history, isolate motor if needed, verify line power, then reset and monitor. That sequence beats guesswork every time.
Step-by-Step Fix
- Capture the fault code and time — Write it down or pull the log before power cycling.
- Look for obvious mechanical issues — Jam, seized bearing, blocked conveyor, or overloaded pump first.
- Check power and cooling — Undervoltage and overtemp faults often have simple physical causes.
- Isolate motor and cable for serious trips — Ground and hardware overcurrent faults demand insulation testing.
- Reset through the proper path — Use keypad reset, digital input reset, or PLC reset per the drive design. Avoid random power cycling as your only method.
- Monitor after restart — Watch current, temperature, and trip timing during a real load cycle.
Parts and Tools Often Needed
| Item | Notes |
|---|---|
| Megohmmeter | Essential for grounding and insulation faults |
| Clamp meter | Check current draw under load |
| Cooling fan | Drive overtemp issues |
| Brake resistor | Needed for repeat overvoltage decel trips |
| Input fuses | For undervoltage and phase-loss issues |
| Parameter backup | Always save settings before replacing a drive |
Need Replacement Parts?
Before ordering, match the drive part to the model number, electrical rating, and failure symptom. Check current prices on Amazon - prices and availability change frequently.
When to Call a Pro
If a VFD keeps tripping on the same code after one informed reset attempt, the reset was never the fix. At that point you need diagnosis, not more resets.