star/delta motor starting

[hsj]

In star/delta motor starting the line contactor(i.e. the contactor other than start(which connects the winding in star) contactor and run(which connects the winding in delta) contactor) is connected inside the delta connection. This contactor can also be connected outside the delta connection. I just want to check that the reason for connecting it inside the delta is to break lower current or anything else.

 

[aolalde]

That contactor can not be outside of the delta because it has two functions: a) connect to the power lines, b) Make the motor winding delta connection. (i.e. connect terminal 1 and terminal 6 together.). Note that motor terminal 1 remains connected to the power line since the start condition.