Classification Based On Principle Of Operation:
(a) Synchronous Motors: These motors have the rotor (which is connected to the load) rotating at the same speed as the speed of rotation of the stator current.
1. Plain
2. Super
(b) Asynchronous Motors: These motors are very flexible to use and matches the load demand almost for everything.
1. Induction Motors:
(a) Squirrel Cage
(b) Slip-Ring (external resistance).
2. Commutator Motors:
(a) Series
(b) Compensated
(c) Shunt
(d) Repulsion
(e) Repulsion-start induction
(f) Repulsion induction
Classification Based On Type Of Current:
1. Single Phase- The single phase motors are generally found their use in low power requirements/domestic appliances like ceiling fans, mixer grinders, portable power tools etc
2. Three Phase- The three phase motors are generally found for high power requirements like power drives for compressors, hydraulic pumps, air conditioning compressors, irrigation pumps and many more.
Classification Based On Speed Of Operation:
1. Constant Speed-There are motors which should be run at a constant speed for air compressors.
2. Variable Speed- Certain cooling water pumps driven by a motors can be run at two or three speeds by just switching the number of poles used. If the number of poles are changed then the speed also changes.
3. Adjustable Speed.
Classification Based On Structural Features:
1. Open
2. Enclosed
3. Semi-enclosed
4. Ventilated
5. Pipe-ventilated
6. Riveted frame-eye
