Understanding lighting contactor

[Andrew Roche]

Hi guys, I'm new on here, I'm a level 3 apprentice, most of my experience is commercial and domestic, my boss has just taken on a large industrial job, in which we are testing and rewiring everything, first we are doing the lights, we will be fitting some lighting contacters, which will run through last man out switches, I know what they are and how they operate inside (the contactors), but for the life of me can't get my head round the wiring arrangements, I have had a look at wiring diagrams on line, and sort of understand, any of your knowledge would be much appreciated.

Many thanks in advance.

 

[westward10]

What are you lost on the control circuit (last person out switch to be PC).

 

[telectrix]

to put it simply. you have several lighting circuits, each circuit controlled by a switch. by fitting a contactor ( 4 pole can switch 4 circuits) and having the contactor coil energised via 1 switch, that switch can then turn on/off the 4 circuits at 1 stroke

 

[Ian1981]

 

[Andrew Roche]

Thanks for the replies, But if you need to take two feeds, one to Permanent, which would be (1), then would you loop out of that and go to the coil (A1) or would that just leave the coil constantly closed, meaning the lights are always on? So really, you would have to loop out of (1) to the last person out switch, which when closed would energise the coil in the contactor (a1), or could I run a 3 core swa straight from the board, so it would have 1 going to the last man out switch, then coil, (A1) one going to the permanent live (1) and a neutral to (3)?

 

[Ian1981]

Thanks for the replies, But if you need to take two feeds, one to Permanent, which would be (1), then would you loop out of that and go to the coil (A1) or would that just leave the coil constantly closed, meaning the lights are always on? So really, you would have to loop out of (1) to the last person out switch, which when closed would energise the coil in the contactor (a1), or could I run a 3 core swa straight from the board, so it would have 1 going to the last man out switch, then coil, (A1) one going to the permanent live (1) and a neutral to (3)?

A2 is generally the only neutral connection on the coil unless you want to make contactor connections double pole.

 

[westward10]

Generally you would have a separate last person out circuit. Line to switch, line back from switch to contactor coil (A1) with a neutral direct from the board to contactor coil (A2).