Frequently asked questions
What can be done when variable speed drives or VFDs are causing motor bearing failures?
FA174066
21 August 2022
Issue:
What can be done when VFDs are causing bearing failures?
Product line:
Altivar All
Environment:
All models, all serial numbers
What can be done when VFDs are causing bearing failures?
Product line:
Altivar All
Environment:
All models, all serial numbers
Cause:
Shaft currents causing the motor bearings to weld.
Resolution:
This phenomena is inherent to VFD use. On the VFD, try lowering the switching frequency to reduce effects but not resolve it.
Other suggestions include:
installing shaft grounding systems
installing insulated bearings
adding a dv/dt filter to couple less voltage to the rotor
adding a common mode filter
verify good grounding from the motor directly back to the VFD
Shaft currents causing the motor bearings to weld.
Resolution:
This phenomena is inherent to VFD use. On the VFD, try lowering the switching frequency to reduce effects but not resolve it.
Other suggestions include:
installing shaft grounding systems
installing insulated bearings
adding a dv/dt filter to couple less voltage to the rotor
adding a common mode filter
verify good grounding from the motor directly back to the VFD