Non stable uncoupled motor magnetic center. 1

[ionize]

We have a 4160 volt ABB motor that when trying to find an uncoupled run magnetic center the rotor won't stabilize.The rotor drifts side to side.This is a 2250 HP motor.During the uncoupled run the amps were stable at approx. 60 and the volts were A)4156 B)4163 C)4170.Motor speed was 3600.Any information related to this would be greatly appreciated.
Thanks

 

[starkopete]

If you have access to the members only portion of EASAs web site they have an excellent paper dealing with magnetic centering, it is tech note #15.