What can be done when variable speed drives or VFDs are causing motor bearing failures?


21 August 2022

What can be done when VFDs are causing bearing failures?

Product line:
Altivar All

All models, all serial numbers
Shaft currents causing the motor bearings to weld.

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