A Third Generation On Line Tool to Find Broken Rotor Bars and Rotor Air Gap Eccentricity in Induction Motors
Breaks in squirrel cage induction motor rotor windings as well as rotor unbalance due to eccentricity have long been known to be a significant cause of motor failures. Broken rotor bars are especially likely in motors driving high inertia loads like fans, or motors that see frequent starting. Rotor air gap eccentricity occurs in motors that have not been properly centered in the stator bore or where the bearings are failing. For 30 years stator current signature analysis (CSA) has been used to objectively detect these problems before failure occurs. However, CSA was prone to false indications that reduced the credibility of CSA measurements. Qualitrol has developed the Iris Power MDSP3, a third generation CSA instrument that drastically reduces the risk of missing these problems or incorrectly indicating that rotor winding faults or eccentricity are present. The result is the more accurate identification of which machines need repairs, an essential element of condition based maintenance. The Iris Power MDSP3 replaces the Iris Power CSMeter, a second generation CSA instrument.
