Protection Engineering Basics and Schemes Protection Engineering | Page 267

Asynchronous motors are those motor that move with
any speed other than synchronous
In any motor initial torque is very high, that is why all
manufacturers allow initial overloading, due to this
reason the motor protection technique is different.
9.1 Abnormal condition
 Over loading
 Loss of 1 phase or all phases
 Motor internal phase to phase, phase to ground or
open circuit
 Blocked Rotor
 Fail to start or prolonged starting
9.2 line interrupting Device
 Magnetic Contactor
 E1 Medium Voltage Motor Controller
 E2 Medium Voltage Motor Controller
9.2.1 Magnetic Contactor
This interrupter is applied for the motor up to 600V level.
This interrupter is equipped with thermal overload and
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