Fault zone analysis: identifying motor defects using the rotor fault zone

In the last decade, advancements in motor testing technology have brought forth advances in online and offline testing. Online current signature analysis (CSA) is quickly becoming a standard industry practice. Offline tests include advanced inductance measurements to analyze rotor and stator health. Using a combination of online and offline tests to form a six fault zone approach offers a more complete analysis of motor health. Power quality focuses on the quality of the voltage and current. Power circuit focuses on the power circuit supplying power to the motor. The stator fault zone focuses on the turn-to-turn insulation and internal coil connections. The air gap fault zone refers to the quality of the air gap between the rotor and the stator. The insulation fault zone refers to the winding to ground insulation. The rotor fault zone refers to the health of the rotor cage and laminations. All six fault zones should be analyzed to accurately assess the overall health of a motor.