Single-Phase Induction Motors
The single-phase engine operates beneath 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 available, a design mechanism is included to begin the motor. These are the various designations:

Torque-Speed Curves of Different Single-Phase Induction Motors

Shaded-pole: Have only one main winding and no start winding. This configuration causes a change of the used magnetic field in relationship to the rotor, creating Single Phase Induction Motor stating torque. Applications consist of enthusiasts and small appliances.

Split-Phase (induction start motor)
Has two models 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 small grinders, small fans, and blowers.

Capacitor-Start
The most common single-phase motor found in industrial applications. It is a modified split-stage motor with a capacitor in series with the beginning winding to supply a start boost. Program include small conveyors, huge blowers, pumps, and direct-drives.

Permanent-Split-Capacitor (PSC)
Uses identical primary and auxiliary windings with a capacitor to provide starting torque. They will be the most reliable single-phase engine because no centrifugal beginning switch is necessary. Applications include supporters and pumps in HVAC and refrigeration industries.