Single-Phase Induction Motors
The single-phase electric motor operates under the same principle as the polyphase engine, except that the rotating magnetic field effect generated by the stator does not exist until running rpm is reached. Since no beginning 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 change of the applied magnetic field in relationship to the rotor, creating stating torque. Applications include followers and small appliances.
Split-Phase (induction start engine)
Has two pieces of stator windings. The “start” windings sit 90 degrees to the “run” windings and shift the magnetic field of the stator, inducing beginning torque. Applications include little grinders, small supporters, and blowers.
The most common single-phase motor used in industrial applications. It is a modified split-stage electric motor with a chain sprocket capacitor in series with the beginning winding to provide a start boost. Application include small conveyors, large blowers, pumps, and direct-drives.
Uses identical primary and auxiliary windings with a capacitor to provide starting torque. They are the most reliable single-phase engine because no centrifugal starting switch is required. Applications include followers and pumps in HVAC and refrigeration industries.