Single-Phase Induction Motors
The single-phase motor operates under 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 available, 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 1 main winding and no start winding. This configuration causes a shift of the applied 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 units 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 fans, and blowers.
Capacitor-Start
The most typical single-phase motor used in industrial applications. It really is a altered split-phase motor with a capacitor in series with the beginning winding to provide a start boost. Application include small conveyors, huge blowers, pumps, and direct-drives.
Permanent-Split-Capacitor (PSC)
Uses identical main and auxiliary windings with a capacitor to provide starting torque. They are the most reliable single-phase motor because no centrifugal beginning switch is necessary. Applications include fans and pumps in HVAC and sprockets refrigeration industries.