We utilize the single-phase power speed reducer program more widely than three phase system for household purposes, commercial purposes and some extent in commercial uses. Because, the single-phase system is less expensive than a three-phase program and the energy requirement in most of the homes, shops, offices are small, which can be easily met by an individual phase system.
The single phase AC motors are further classified as:
One phase induction motors or asynchronous motors.
Single phase synchronous motors.
The squirrel cage rotor contains aluminum, brass or copper bars. These light weight aluminum or copper bars are called rotor conductors and positioned in the slot machine games on the periphery of the rotor. The copper or aluminium rings permanently short the rotor conductors known as the end rings.
To provide mechanical strength, these rotor conductors are braced to the end ring and therefore form a complete closed circuit resembling a cage and hence got its name since squirrel cage induction engine. As end rings completely short the bars, the rotor electrical level of resistance is very small in fact it is not feasible to add external resistance as the pubs get permanently shorted. The lack of slip ring and brushes make the construction of single phase induction motor very simple and robust.