Single-Phase Induction Motors
The single-phase motor operates beneath the same principle as the polyphase electric motor, except that the rotating magnetic field effect generated by the stator does not exist until running rpm is reached. Since no starting torque is obtainable, a design mechanism is included to start the motor. They are the various designations:
Torque-Speed Curves of Different Single-Phase Induction Motors
Shaded-pole: Have only 1 main winding and no start winding. This configuration causes a change of the used magnetic field in relationship to the rotor, creating stating torque. Applications consist of fans and small appliances.
Split-Phase (induction start motor)
Has two sets of stator windings. The “start” windings are positioned 90 degrees to the “run” windings and shift the magnetic field of the stator, inducing beginning torque. Applications include small grinders, small fans, and blowers.
The most common single-phase motor used in industrial applications. It is a altered split-phase engine with a capacitor in series with the beginning winding to provide a start boost. Application include small sprockets conveyors, huge blowers, pumps, and direct-drives.
Uses identical primary and auxiliary windings with a capacitor to supply starting torque. They will be the most reliable single-phase electric motor because no centrifugal beginning switch is necessary. Applications include followers and pumps in HVAC and refrigeration industries.