Evaluation of progressive deterioration of a squirrel-cage rotor, with a condition monitoring system that implements the sideband methodology

The Motor Current Signature Analysis (MCSA), is one of the most used methods to diagnose failures on squirrel cage induction rotors. This paper presents the application of the MSCA to the experimental test results, performed on an initially healthy motor, which has several rotor bars progressively fractured. The tests were applied using a monitoring condition system, developed in LabVIEW®, designed to detect the sidebands. The results show that the loading of the motor has an important effect in the magnitude difference between the fundamental harmonic, and the lower sideband.