Question about star-delta control circuit diagram

Foxfl said:

K1T ( n.c.) is in wrong location. It should be on 2nd rung to open k1 resulting in k3 being energized by k1 interlock . Basically transition from wye to delta connection.

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lemau said:

Hi Shilpesh
From your circuit diagram,K1 is for STAR connection.For Star delta Starter,The first sequence after you press ON push button is K1 MUST energize first before K2.Why? because if K2 energize first before K1 it can cause the spark and can damage the contactor. The Key point for star connection is to start the motor in 240 Volt to reduce high in rush ampere and build a torque..after a motor achieve 80% running..it switch to Delta.It mean the motor running with full capacity ( 415 volt )..For more detail,please read some post about star delta starter below :-

http://www.electricneutron.com/electric-motor/star-delta-motor-connection/
http://www.electricneutron.com/motor-control/star-delta-starter/

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