A motor with only armortisseur windings is called an induction motor. An induction motor is the most modest electrical machine from constructional point of view, in the majority of the cases. Induction motor works on the principle of induction where electro-magnetic field is induced into the rotor when rotating magnetic field of stator cuts the stationary rotor. Induction machines are by far the most common type of motor used in industrial, commercial or residential settings. It is a three phase AC motor. Its characteristic features are: Simple and rugged construction Low cost and minimum maintenance High dependability and sufficiently high proficiency Needs no additional starting motor and necessity not be synchronized Three-Phase Induction Motor: These motors are self-starting and use no capacitor, start winding, centrifugal switch or other starting device. Three-phase AC induction motors are widely used in industrial and commercial applications. These are of two types, squirrel cage and slip ring motors. Squirrel cage motors are widely used due to their rugged construction and simple design. Slip ring motors require external resistors to have high starting torque. Induction motors are used in industry and domestic appliances because these are rugged in construction requiring hardly any maintenance, that they are comparatively cheap, and require supply only to the stator. Applications of Three Phase Induction Motor Lifts Cranes Hoists Large capacity exhaust fans Driving lathe machines Crushers Oil extracting mills Textile and etc.