Question
Download Solution PDFA repulsion start induction run single phase motor runs as an IM only when ________.
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFRepulsion-Start Induction-Run Motor
- A repulsion-start induction-run motor consists of a stator carrying a single-phase exciting winding and a rotor that has a closed-type armature winding with a commutator and brushes.
- This motor is started as a repulsion motor with a corresponding high-starting torque. At some predetermined speed, a centrifugal switch short-circuits the commutator segments so that the motor operates as a 1-phase induction motor.
- A repulsion start induction run single phase motor runs as an IM only when the brushes on the commutator are short-circuited.
- The centrifugal device is fitted on the rotor shaft of the motor. When the motor attains about 80% of its normal speed, the centrifugal device forces a short-circuiting ring to come in contact with the inner surface of the commutator which short-circuits all the commutator bars. Then, the rotor resembles the squirrel cage type rotor and the motor operates as a 1-phase induction motor.
Applications of Repulsion-Start Induction-Run Motor:
Due to the high starting torque, these motors are used to drive Refrigerators, Pumps, Compressors, etc.
Last updated on Jun 16, 2025
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