Effectiveness of vibration and current monitoring in detecting broken rotor bar and bearing faults in an induction motor

Induction motors are widely used prime-movers in most of the industrial applications due to its high efficiency, rugged design and easy control. Reliability and availability of induction motors is one of the required parameters in order to reduce down-time of the entire rotating machinery system. Vibration analysis and motor current signature analysis (MCSA) are widely used diagnostic techniques for the detection of various mechanical and electrical faults in induction motors. Major limitation of the MCSA is its inability in detection of faults in induction motors at no load condition. This paper addresses this limitation and proposes a suitable technique for more effective fault detection of an induction motor using vibration spectrum at no load condition. The results have been experimentally tested and validated in an electrical fault simulator set-up for broken rotor bar and bearing faults.