3 Phase Synchronous Motors

[Ogeerster]

When starting 3 phase synchronous motors, they require a high starting current 4-7 times the full load current. If this current is taken from the 3 phase supply, the phase windings will burn out, to prevent this, they use starters to start 3 phase synchronous motors.

There are some methods of starting:

-Direct-On Line Starting
-Star Delta Starting
-Auto Transformer Starting

and there is Resistance starting. I have never came across Resistance starting before so if anyone has any knowledge about resistance starting with respect to 3 phase synchronous motors, i will very much be grateful.. Thanks!

 

[Guest123]

See attached PDF......you'll probably understand that better than my waffling!!

 

[spud1]

Resistance starting is a method of starting that reduces starting currents by using resistors in the start up. Much like star delta starting reduces start currents variable restance is applied to motor winding a its highest to start and reduced to run.

 

[Ogeerster]

Much thanks Lenny! ^.^