Light switch wiring question..

[Cap'n]

Hi... The other day my bathroom light/fan switch (double switch/single gang), got burning hot to the touch. I pulled the fuse & unscrewed the switch - you can see it here (hope this works!):

[IMG] you can see, there are 4 incoming red wires , and 1 yellow. There is also 1 red going from one terminal to another. Three of the red wires go into the same terminal, & it looks like it's here that the problem started (if you tilted the switch upwards & looked at it head- on, the left switch is for the single light, and the right switch is for the second light + the extractor fan).

What I don't understand is if this was supposed to *be* like this (and has been working as such), why this happened?

Can anyone offer advice?

Cheers ... Mark

[Cap'n]

OK - got that a bit wrong...maybe this:

And also there *4* of the wires go into that one terminal...don't know how I missed that!!

Cheers ... Mark

[Cap'n]

Oh god! third time:

[Lurch]

On 3 Mar 2007 03:11:32 -0800, "Cap'n" mused:

If it's been working then obviously it's correct, don't start playing with it and trying to wrk out what it's doing.

The reason it's hapend is because some plum has rammed too many cables in one terminal without securing them adequately and this has resulted in arcing and burning, which has eventually got to this stage by gradually becoming worse and worse as more arcing occurs and the resistance builds up every time you use the lights.

Call an electrician.

[Cap'n]

Too optimistic to assume cutting back the wires & connecting them back up the same way (making sure all's secure) would work?

[Jason]

I don't think there is a lot more you could do. When replacing the wires, make sure they are all firmly and evenly twisted together, so they make good contact with each other, regardless of how tight the screwn is.

And replace the switch - you don't know what damage the heat has done.

-- JJ

[Lurch]

On Sat, 03 Mar 2007 11:57:06 GMT, "Jason" mused:

Not good practice to twist all the wires together. There should be no problems with not having them twisted together as long as the switch is fitted properly. Twisiting all the wires together weakens the conductors.

[Mike Tomlinson]

In article , Lurch writes

3 wires in each common, since a link wire will still be needed.

[Cap'n]

So - as the 'link' wire (I assume the wire going from one terminal to the other) is one of the four, I'd take *1* out of the original common and put it in the 2nd common (giving 2 in there, and leaving 3 in the original common - with those other two (single red and single yellow) as they are.

Mark

[Cap'n]

Does this look OK?

I took one of the reds out of the original common, & put it in the second common (figured if they were connected via the 'link' wire anyway it'd be OK). Otherwise everything is the same it was on the original switch (just got a new one at B&Q).

Cheers ... Mark

[Lobster]

You are sure that the switch is configured the same way though: ie you've matched up the L1, L2 and C terminals in the new and old switches? I've often found that they are in different relative positions.

David

[Cap'n]

Yeah - I'm sure I did..!

Anyway, it seems to work fine - nothing shorted/burst into flames/ knocked the building's power out so I guess it's OK.

[Stephen Dawson]

Do not twist the wires together, this is what probably caused the original fault.