Single-Phase Induction Motors
The single-phase engine operates beneath the same principle as the polyphase motor, except that the rotating magnetic field effect produced by the stator will not exist until running rpm is reached. Since no starting torque is obtainable, a design mechanism is included to start 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 begin winding. This configuration causes a shift of the applied magnetic field in relationship to the rotor, creating stating torque. Applications include followers and small appliances.
Split-Phase (induction start 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 beginning torque. Applications include little grinders, small followers, and blowers.
Capacitor-Start
The most typical single-phase motor found in industrial applications. It is a altered split-stage engine with a capacitor in series with the start winding to provide a start boost. App include small conveyors, huge blowers, pumps, and direct-drives.
Permanent-Split-Capacitor (PSC)
Uses identical primary and sprockets auxiliary windings with a capacitor to provide starting torque. They are the most reliable single-phase motor because no centrifugal starting switch is required. Applications include fans and pumps in HVAC and refrigeration industries.