Classification of A.C. Motors

For the use of light an power, the system of distribution of electric energy the field of application of A.C. motors are widely used. Due to rapid use of motors the manufacturers have tried over the last few decades, to perfect various types of ac motors suitable for all classes of industrial drives and for both single and three phases a.c. supply.

This has been rise to bewildering multiplicity of types whose proper classification often offers considerable difficulty. Different a.c. motors may, however be classified and divided into various groups and as following as below.

1: Due to their principle of operation

A: Synchronous motors

(i) Plain  (ii) super

B: Asynchronous motors

a: Induction motors

   (i) Squirrel cage ( single / double)   (ii) Slip ring (external resistance) 

b: commutator motors

    (i) series (single phase / universal)        (ii) compensated ( conductively/inductively)        

   (iii) Shunt ( simple / compensated)   (iv) Repulsion (straight / compensated)          (v) repulsion-start induction      (vi) repulsion induction

2: Due to the type of current

(a) single phase        (b) three phase

3: Due to the speed

(a) constant speed     (b) variable speed    (c) adjustable speed

4: Due to Structural features

(a) open        (b) enclosed     (c) semi-enclosed      (d) ventilated     (e) Pipe-ventilated    (f) riveted frame eye