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Shaft Ground Motor Warranty


Baldor Electric Company guarantees that any new Baldor motor equipped with a shaft grounding device will not have bearing failure from variable frequency drive (VFD) induced electrical bearing damage during the Baldor motor warranty period. The motor bearing protection shall match the same warranty time period of the Baldor motor on which a shaft grounding device is installed in a Baldor manufacturing facility.

Definition of Bearing Failure

Motor bearing failure which originates due to VFD induced electrical bearing damage is caused by electrical discharge machining (EDM) pitting damage in the bearing race. This is referred to as “frosting” or “fluting” of the bearing race of a sufficient amount to cause unacceptable audible noise.

The bearing damage resulting in noise must have originated directly from the VFD induced electrical bearing discharges during normal motor operation. The inner and/or outer race of the bearing will usually have visible EDM, often with a fluted perpendicular or washboard pattern or frosting. Bearing failure or unacceptable audible noise caused by other mechanical means other than VFD induced bearing current shall not be covered by this warranty.

Motors Eligible for the Shaft Ground Guarantee

The Shaft Ground Guarantee covers only new motors with the original motor bearings installed. This includes any new motor manufactured by Baldor with a shaft ground installed, as well as any new motor modified in the Baldor Mod Express® shop. The guarantee covers the following motors:
  1. Motors up to 100 Hp/75 kW with single row radial ball bearings with a shaft grounding device installed on either end of the motor's shaft.
  2. Motors over 100 Hp/75 kW up to a NEMA 449T/IEC 280 frame with single row radial ball bearings with a shaft grounding device installed on either end of the motor's shaft. The motor must also be equipped with an insulated bearing or ceramic rolling element bearing installed on the opposite end of the motor on which the shaft grounding device is installed.
  3. This guarantee does not cover motors where the shaft grounding device was misused in the application.

Warranty Redemption Process

Should a bearing failure occur due to EDM damage during the motor warranty period, please contact your local Baldor sales representative or refer to the "Procedure to Receive Warranty Service" listed under the standard warranty on baldor.com. Be sure to specify the defect as "fluting/frosting - with shaft ground". Baldor reserves the right to inspect the motor, motor bearings, and shaft ground device upon request.


Baldor does not cover bearing failure due to EDM damage on any of its motors that have been retrofitted with a shaft grounding device in an aftermarket environment.

Comments & Questions

We welcome comments and questions regarding our warranty.

Customer Service:
  • ABB Motors and Mechanical Inc.
  • P.O. Box 2400
  • Fort Smith, Arkansas 72902
  • Facsimile: 479-648-5791
  • Contact Sales Office