Protection Engineering Basics and Schemes Protection Engineering | Page 266

Chapter 9

Motor Protection

any equipment convert electrical energy into mechanical power is motor, available motor in market is in rating of few KW or horse power to required KW or Horse power, now question is why we rate motor in horse power? Answer is quite simple that initially for good transportation and travel we used horses and to show the efficacy of this new equipment or invention scientist compared invention efficiency with horse’ s power of movement.

Our motors are inductive in nature, we subdivided motors into synchronous motors and asynchronous motors. Synchronous motors run with synchronous speed

Where,

Speed synchronous = 120f p f is frequency p is the number of poles pg. 266