Rotor Failure CausesGenerally, rotor failures occur due to two major factors:
Excessive heat can result from operation on continuous overload, motor stall and too many starts in succession without adequate cool down, combined with excessive accelerating time. Discoloration or burning of the insulation system can confirm a failure from excessive heat and lead to phase-to-phase faults and turn-to-turn shorts within the rotor winding. Mechanical stress failures are generally due to repetitive centrifugal loading on the coil extensions or coil end-arm vibration. If a motor is subjected to frequent starts, the forces generated in the rotor can cause bar fatigue failures, especially if high temperature is present. Coil failure can also occur when the bars are loose in their slots, allowing them to vibrate. This situation happens most frequently on starting and during motor acceleration. For More Information For a detailed service description, click the following link: Find a service center that performs Motor servicesRelated InformationRequest a quote |