Technical Guide
Common VFD Faults and What They Mean
Explains over current, earth fault, DC bus, input phase, output phase, and no-display conditions in factory language.
Component-Level Diagnosis
Warranty Support
Production Downtime Focus
Decision Notes
- Over-current alarms can come from the motor, cable, load jam, IGBT stage, current sensor, or wrong acceleration settings.
- Earth fault should be treated seriously because it may indicate motor insulation failure, cable damage, or drive output leakage.
- No-display faults usually require checking the input stage, charging resistor, SMPS, control board, and keypad supply path.
Practical next step: Share the brand, model number, fault code, machine type, and urgency. This helps separate repairable electronics faults from machine-side wiring, motor, load, or parameter issues.