4 wires 3 holes

[Phil W]

I have bought a 1 gang 2 way switch to replace an old switch. There are three switches (kitchen) for one light fitting (there are three entrances to the kitchen). On the back of the old switch there are 4 holes, at top, one red wire, one black wire. At bottom the same. The new switch only has three holes (common, two way and one way) I am unsure where to put what wire....

Any help appreciated.

Cheers,

Phil

 

[amtodd]

Phil,

For there to be three switches on one circuit, two of the switches will be two way, and the middle one will be an intermediate. An intermediate swaps A-A & B-B to A-B and B-A. A two way switches common to A or B. Switching any of the switches will change the state of the lamp from on to off or back again.

The two way switches will have three holes and the intermediate will have four.

My guess is that you are trying to replace an intermediate with an two way.

There was a how to on these pages, I can't remember where, but do a search.

 

[Phil W]

thank you...

I only looked at one of the switches, so that must be the intermediate you mention.

What should I buy to replace this switch then? Is the answer as simple as "one with four holes?"

I'll check the other two switches to see how they differ....

Thanks again...

 

[ban-all-sheds]

...I only looked at one of the switches, so that must be the intermediate you mention.

What should I buy to replace this switch then? Is the answer as simple as "one with four holes?"...

No - the answer is as simple as "to replace an intermediate switch you should buy an intermediate switch"

http://www.tlc-direct.co.uk/perl/search.pl?search=intermediate&Submit=Search

 

[Phil W]

just checked.....one of the other switches is the same as the one I bought.....like for like.

I didn't take the third of the wall (it's practically plastered in.....so will wait) but I expect to find the same...

Cheers,

Phil

 

[ban-all-sheds]

That's what I'd expect too. For a total of n switches in a light circuit (where n>2), 2 of them will be two-way, and n-2 will be intermediates.

Although it is possible to wire an intermediate up as a normal 2-way. To visualise how they work, imagine the terminals as the 4 corners of a square, so you've got Top Left, Top Right, Bottom Left & Bottom Right.

With the rocker in one position the connections made are TL-BL and TR-BR, and with it in the other position the connections are TL-BR and TR-BL.

So you could get the functionality of a 2-way switch by using TL as COM and BL & BR as L1 & L2.

 

[Phil W]

thank you...I think I'm on top of it now...

many thanks for everyone's help...

Phil