Single-Phase Induction Motors
The single-phase engine operates under the same principle as the polyphase motor, except that the rotating magnetic field effect produced by the stator does not exist until running rpm is reached. Since no beginning torque is offered, a design system is included to start the motor. They are the various designations:

Torque-Speed Curves of Different Single-Phase Induction Motors

Shaded-pole: Have only one main winding and no begin winding. This configuration causes a change of the applied magnetic field in relationship to the rotor, sprockets creating stating torque. Applications include fans and small appliances.

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

Capacitor-Start
The most common single-phase motor found in industrial applications. It is a modified split-phase engine with a capacitor in series with the beginning winding to provide a start boost. Program 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 beginning switch is necessary. Applications include supporters and pumps in HVAC and refrigeration industries.