What is the function of Motor in the motorized circuit breakers?

[tipu_sultan]

Can any one explain that and in which category we placed motorized circuit breakers?
If we put motor on the RCD then, is it called motorized RCD?
And am I hope the same case with EFI?

 

[chuckey]

"motorized" circuit breakers use the motors to re-charge the mechanical springs that actually perform the moving of the contacts. The motors are often 50 V battery supported, so they can be operated when there is no mains available.
Motorized circuit breakers are used on high power circuits, we had them on a 11KV incoming supply that fed a 1MW 440V transformer. The actual trip was a 50V coil circuit, so passing 50 mA current through the trip circuit, caused the switch to open (on the springs) and break the 1 MW circuit. So the earth leakage would only be one of several things that fired the switch (over current, loss of a phase. . . )
Frank