three-way switching - bodged? safe?

Andrew · Post by **Andrew** » Sun Jan 21, 2007 8:26 pm

In my flat, there are two lights in the hallway - one and the top of the stairs and one at the bottom. Both lights come on and go off at the same time - they aren't independant.

There are three switches that control them.

The first two switches work okay. One is at the bottom of the stairs and one is at the top. However, looking at the wiring at these switches, they don't appear as I would have expected. In both, there seem to be 2 x two core and earth cables. One of these cables has both live and neutral going to the switch, whilst the other cable only has live going to the switch - the neutral appears to have been cut short.

The third switch is really strange. It seems to be a master switch in that it overrides the other two (i.e. if you turn the lights on with it, you can't turn the lights out with the other switches).

I'm considering killing off the third switch and just using the other two.

I know this setup isn't right. What I want to know is: is if safe?

If I had to re-wire it, is there a way of swapping wires without chasing out the walls?

Many thanks.

Hinton Heating · Post by **Hinton Heating** » Sun Jan 21, 2007 8:33 pm

I think you'll need to draw a wiring diagram of what you actually have first to understand what is happening.

the 2 x 2+E seem to be correct as just taking the place of a 3+E which is normally used.

Post by **ultimatehandyman** » Sun Jan 21, 2007 8:38 pm

This is how a three way lighting arrangement can be wired-

http://www.ultimatehandyman.co.uk/three ... ghting.htm

One of your switches will be an intermeidate switch and two of them will be two way switches.

You should be able to sort out the wiring by following the page above, if not post back

Andrew · Post by **Andrew** » Mon Jan 22, 2007 8:40 am

Thanks for the replies, I will def post back at some point. It may be a while though as I'll have to get in the loft with a torch and track the wires around and see where the wiring goes etc, and I've got other things above that on the list at the mo' (yep, ordered in a plasterer in the end and have to prepare for him!).

I'm glad that no-one seems to think this is utterly unsafe though. I never related two lots of twin core and earth to simply be a replacement for the 3 core wires. Still, seems more hassle to do it that way than just to use proper cable.

Many thanks and I'll keep you posted (albeit in a few weeks).

sparkydude · Post by **sparkydude** » Mon Jan 22, 2007 6:20 pm

Nothing wrong with this set up, as long as the cables are both earthed, no problem. Sounds like the switch in the middle might be wired up wrong. Just one thing to check , have you got 1 or 2 lighting circuits? and if you turn off the upstairs lighting do they go off, or the downstairs . Just trying to make sure the feeds are not crossed or linked out.

Nick

Andrew · Post by **Andrew** » Wed Jan 24, 2007 9:07 am

I've only got one lighting circuit (I live in a flat, so only one level, and I only have one lighting fuse at the consumer unit).

Seeing how everything else was done in my place, the third switch is almost guaranteed to be wired up wrong! :mad: There's only 1 x 2+E cabling going to it, so I presume something un-orthodox is going on somewhere. I'll spec it out in a week or so when I get a chance to go in the loft.

But thanks for re-assurance that the other switches are safe. When I see something that's not as expected (especially electrics), I begin to get a tad wary.

Andrew

Andrew · Post by **Andrew** » Sun May 20, 2007 6:54 pm

Hi, thought I'd give a little update on the below thread.

I went up into the loft the other day, and tried to make a little more sense of what is going on. I discovered one thing: the cabling for the light switch which doesn't seem to fit in with the whole two-way lighting is merely a cable which runs from the light switch into the ceiling rose (along with what seems like an ungodly amount of other wires!).

I guess that probably answers my question of why it isnt working how I thought it would work.

My question: however it is wired up, would it be safe to simply remove this lone wire and switch as if it was never there? That sounds logical, but could it be an integral part and removing it mean the rest doesn't work?

Here's some really unclear (and large) pictures to (not) help you. Many thanks.

Andrew · Post by **Andrew** » Wed May 23, 2007 7:13 am

Further to this, I can also tell you there are 6 cables entering the ceiling rose. I've not tracked them back yet, but one is the single cable coming from the rogue switch I'm talking about in this post, one is the light cable coming from the previous light, and one is the light cable going to the next light. The other three I've not tracked back yet.

Post by **ultimatehandyman** » Wed May 23, 2007 7:47 am

That is a very busy looking ceiling rose, it looks like spaghetti junction!

I can't make out what some of those wires are doing

Andrew · Post by **Andrew** » Wed May 23, 2007 9:29 am

i think in all honesty i am probably going to have to draw a diagram for anyone to be able to help, but i really don't want to mess around and get it wrong and not be able to sort it out. as you say, it's a nightmare, and i've never even wired a ceiling rose before.

gentoo_ · Post by **gentoo_** » Thu May 24, 2007 3:40 am

Because there seems to be 4 neutrals I assumed they must power two lights but there's only one wire (I think) apart from you buld holder that's connected to your live/ switched live terminal.
I'll draw a diagram of how it should be wired but don't do anything until someone more knolagble gives their advise on how (if you can) wire everything up.

gentoo_ · Post by **gentoo_** » Thu May 24, 2007 4:42 am

I just re-read your post it does power two lights....

My diagram shows how it should be wired up using the normal method but while making I think that they might have wired it up using a wire saving method and have connected all the wires up at the ceiling rose instead of the switches. That's why you have 6 wires instead of 4. I'll post the diagram anyways incase it might be useful.

The two terminal block you see is where the brown bulb holder wire should be. Who ever wired yours up has put it in the wrong place but maybe you can do that when you use that method, I dunno.
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Andrew · Post by **Andrew** » Thu May 24, 2007 7:17 am

Thanks for your reply, most helpful. Just got to pluck up the courage now!

skiking · Post by **skiking** » Thu May 24, 2007 7:29 am

TURN THE POWER OFF FIRST

gentoo_ · Post by **gentoo_** » Thu May 24, 2007 9:28 am

Andrew wrote:Thanks for your reply, most helpful. Just got to pluck up the courage now!

No you can't do it that way. I'd allmost finished my diagram before I realised (I could be wrong, never done any wiring) that the wires that are normally connected at the switches are connected at the celiling rose instead.

If they have done it that way all the commons would have to go into a wire connector strip and some wires would go into your center loop terminal but I've no idea what to do with the rest. I'm not even sure if it's legal or safe with a three way switch. You can do it with a two way though.