Single-Phase Induction Motors
The single-phase electric motor 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 starting torque is obtainable, 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 1 main winding no begin winding. This configuration causes a change of the used magnetic field in relationship to the rotor, creating stating torque. Applications consist of enthusiasts 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 beginning torque. Applications include small grinders, small enthusiasts, and blowers.
The most typical single-phase motor found in industrial applications. It really is a modified split-phase engine with a capacitor in series with the start winding to provide a start boost. Application include small conveyors, large blowers, pumps, and direct-drives.
Uses identical main and auxiliary windings with a capacitor to supply starting torque. They are the most reliable single-phase motor because no centrifugal starting switch is required. Applications include followers and pumps in HVAC and refrigeration chain sprocket industries.