Overfrequency
Lenze · SHB4800/4900
What does OF mean?
This fault indicates that the frequency of the incoming mains power supply has risen above the specified operating range. By default, this critical condition triggers a full TRIP, inhibiting all ignition pulses and resetting the Ready signal to prevent damage to the drive and motor that could result from operation at an incorrect frequency. Manual reset is required after the frequency stabilizes.
Complete Troubleshooting Guide
- 1
Measure incoming mains frequency: Use a power meter or multimeter with frequency measurement capability to check the supply frequency.
- 2
Verify grid stability: Consult with facility electricians or the utility provider regarding any issues with the power grid frequency.
- 3
Check for malfunctioning generators: If the drive is powered by a local generator, investigate if it's overspeeding or malfunctioning.
- 4
Inspect power distribution equipment: Check for issues in transformers or switchgear that could affect frequency.
- 5
Ensure frequency monitoring parameters are correctly set in the drive (if applicable).