The main factor that characterizes the induction electric motor is the process in which only the stator is connected to the mains supply and the rotor is not fed from the external side, and the currents that freely circulate in it are electromagnetically induced by the stator, to the origin of its induction motor name.
The induction motors use a rotor called the squirrel cage, which has a reelcraft D9299 OLPBW special starting device, where this special device consists of a winding starting to the stator. Single-phase motors only have a single power phase and have no rotating field, like polyphase motors, but they have a pulsating magnetic field. This factor will allow the impediment so that they have conjugate for the starting, since in the rotor induce magnetic fields aligned with the field of the stator.
Single-phase induction motors rely on only one phase and are powered by a single-phase alternating current, they are often used when we need a smaller motor and less power. The main advantage considered of this type of motor is its low cost for small powers.