Which source drive the star delta contactor

[layzbass]

Hi sorry for my newbie question, I've a question about a star delta starter. What exactly drive the mechanical contact in contactor, is't AC 240/220V separate source from L1,L2,L3? thanks.

 

[johnboy6083]

a contactor is a large relay. It has an electric magnet inside it, called a coil. the connections for this are usually labelled as A1 and A2.
when the coil is energised, it will pull the contactor in, and operate either normally open (NO) or normally closed (NC) contacts. The coil can be fed from the same source as the contactor, or from a different MCB, or as is often the case, through an ELV transformer.

 

[Knobhead]

If the control is 240V there needs to be a neutral to the starter. It’s good practice to take the control from L1 via a fuse.

 

[ackbarthestar]

Also
The changeover mechanism from star to delta must be mechanical interlocked to stop both star and delta contactors being on simultaneously, however shorter time, so that it doesn't go caboom !

 

[layzbass]

Thanks, you guys really help me out

 

[layzbass]

Please find the picture above,the D.O.L diagram. Anyone can tell me how the auxiliary NO working base on the schematic diagram. Tq