I. Introduction
Induction motors are widely used in modern industry and commonly in diverse critical applications such as nuclear reactor coolant pumps, petrochemical turbines, and military applications, where high reliability and efficiency are required. They present 80% of the motors in use [1]. In spite of their robustness and high efficiency, they can be the seat of a wide-ranging of failures that can lead to total motor failure, and will directly influence the safe and reliable operation of the whole plant. In this context, condition monitoring and fault diagnosis systems are developed to guarantee a continuous safe operating, and early fault detection and severity evaluation. This system should be reliable and accurate with no false or missed alarms [2].