Single-Phase Induction Motors
The single-phase motor operates beneath the same principle as the polyphase motor, except that the rotating magnetic field effect generated by the stator does not exist until running rpm is reached. Since no sprockets starting torque is offered, a design mechanism is included to start the motor. These are the various designations:
Torque-Speed Curves of Different Single-Phase Induction Motors
Shaded-pole: Have only one main winding no begin winding. This configuration causes a shift of the applied magnetic field in relationship to the rotor, creating stating torque. Applications include enthusiasts and small appliances.
Split-Phase (induction start engine)
Has two units of stator windings. The “start” windings are positioned 90 degrees to the “run” windings and change the magnetic field of the stator, inducing beginning torque. Applications include little grinders, small fans, and blowers.
Capacitor-Start
The most typical single-phase motor found in industrial applications. It is a modified split-stage electric motor with a capacitor in series with the start winding to supply a start boost. Application include small conveyors, huge blowers, pumps, and direct-drives.
Permanent-Split-Capacitor (PSC)
Uses identical main and auxiliary windings with a capacitor to supply starting torque. They are the most reliable single-phase engine because no centrifugal starting switch is necessary. Applications include followers and pumps in HVAC and refrigeration industries.