Toshiba VFD Fault Codes
Toshiba VF-S15 and VF-S9 drives use compact fault labels that cover motor overload, DC bus faults, overheating, and memory errors.
Common Toshiba Faults
| Fault | Meaning | Quick Fix |
|---|---|---|
| OC | Overcurrent | Check motor/cable short, jammed load |
| OV | Overvoltage | Increase decel, check braking setup |
| OH | Heatsink overtemperature | Clean drive, verify cooling fan |
| OL1 | Motor overload | Check motor FLA setting |
| OL2 | Drive overload | Reduce load, check sizing |
| LU | Undervoltage | Check input supply and loose terminals |
| EF | External fault input | Check interlock wired to fault terminal |
| CPF | CPU/EEPROM fault | Power cycle, replace drive if persistent |
Key Troubleshooting Notes
- LU faults often come from weak plant power or loose line terminals.
- CPF faults can happen after surges or aging electronics.
- OL1 and OL2 often point to bad parameter setup, not just a heavy load.
Bottom Line
Toshiba faults are usually straightforward. Check supply voltage, motor current settings, decel time, and cooling before condemning the drive.