Drive cooling fan
Common heat-related VFD and servo-drive failure point.
VFD Fault Code Lookup — Start Here
Variable frequency drive faults look brand-specific on the screen, but most of them reduce to a small set of root causes: overcurrent, overvoltage, undervoltage, overtemperature, communication loss, and motor feedback issues. This page helps technicians classify the fault before going to the drive-specific guide.
Common VFD Fault Patterns
| Fault Type | What It Usually Means |
|---|---|
| Overcurrent | Mechanical bind, cable short, ramp too fast |
| Overvoltage | Decel too fast, regenerative load |
| Undervoltage | Supply loss or weak incoming power |
| Overtemperature | Cooling failure or hot enclosure |
| Ground fault | Motor or cable insulation breakdown |
| Communication fault | PLC, fieldbus, or keypad/network issue |
Brands Covered
- ABB
- Danfoss
- Siemens
- Schneider Electric
- Mitsubishi
- Yaskawa
- Allen-Bradley PowerFlex
- Toshiba and others
Step-by-Step Fix
- Capture the exact code and operating state — accel, run, decel, or idle.
- Separate load issues from drive issues — Can the motor/load turn freely?
- Check incoming power quality.
- Inspect motor cable, grounding, and enclosure cooling.
- Review parameters only after hardware basics are verified.
Parts Often Needed
| Part | Notes |
|---|---|
| Cooling fan | Frequent source of thermal faults |
| Braking resistor | Needed for fast-stop applications |
| Keypad / HMI | For local diagnostics |
| Replacement drive | For confirmed internal hardware faults |
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 the drive faults with the motor disconnected, or if you see repeated hardware or DC bus faults, involve a qualified drive technician. Parameter guessing and repeated resets can make a controllable problem much more expensive.