motor bearings

[phidias]

i do warranty work for a large pump manufacture and recently i have noticed a large number of motor bearing failures. the bearings that are fitted are de c3 and nde c4 differant sizes. the failure is a high pitched what i would like to know is. is this due to the temp of the application and the clearance of the bearings. when motor is stripped the bearings feel ok so i am at a loss at why they are failing. if anyone could explane/help please.

 

[Artisi]

The best solution is to give the bearings to the bearing manufacturer for a failure analysis.

 

[Valvecrazy]

Are these pumps controlled with a VFD?

 

[phidias]

the failures are on both dol and vfd motors