On-line current monitoring to diagnose airgap eccentricity-an industrial case history of a large high-voltage three-phase induction motor

An appraisal of online monitoring techniques to detect airgap eccentricity in three-phase induction motors is presented. Results from an industrial case history show that an improved interpretation of the current spectrum can increase the reliability of diagnosing airgap eccentricity in large HV three-phase induction motors.