On-line MCSA to diagnose shorted turns in low voltage stator windings of 3-phase induction motors prior to failure

This paper focuses on experimental results to prove that motor current signature analysis (MCSA) can diagnose shorted turns in low voltage stator windings of 3-phase induction motors. The diagnostic strategy is presented and variables that influence the diagnosis are discussed. Current spectra from motors with short-circuited turns (with and without short circuit current limiting resistors) are presented and fully analysed. Results from motors tested to failure are reported. The results in this paper were from industrial motors of different pole numbers with concentric and lap wound winding designs. Since stator failures account for a high percentage of failures the results are particularly relevant to industry.