Single-Phase Induction Motors

Single-Phase Induction Motors
The single-phase engine operates beneath the same principle as the polyphase electric motor, except that the rotating magnetic field effect produced by the stator does not exist until running rpm is reached. Since no starting torque is offered, a design mechanism is included to begin the motor. They 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 used magnetic field in relationship to the rotor, creating stating torque. Applications include followers and small appliances.

Split-Phase (induction start electric motor)
Has two sets of stator windings. The “start” windings sit 90 degrees to the “run” windings and change the magnetic field of the stator, inducing starting torque. Applications include little grinders, small enthusiasts, and blowers.

Capacitor-Start
The most common single-phase motor found in chain sprocket industrial applications. It is a altered split-stage engine with a capacitor in series with the beginning winding to provide a start boost. App include small conveyors, large 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 required. Applications include enthusiasts and pumps in HVAC and refrigeration industries.