2 gang 2 way switches HELP!!

[mediamogul]

Please help! I have just bought a new house and am struggling with the kitchen lights. I have three lights, 2 at one end of the kitchen and one at the other end. There are two 2 gang switches to control these but I have taken them off and can't put them back together and get them to work. At the first switch I have 2 cables with red and black wires (tagged red) and a 2 way cable (blue, yellow, red). The switch for this has 2 switches on the back, each with a common, L1 and L2. The switch at the far end of the kitchen has a red and black cable and the 2way cable. The fitting is an older version, with the diagonal line across the back and the commons on opposite sides of the line. Am I right in thinking that this second switch is wired for one way operation for the single light at that end of the kitchen and 2 way operation of the two lights at the other end? Are the two red/black cables at the first end interchangeable or do I have to give one priority over the other? How do I wire the switches to work?

 

[breezer]

it depends on how wired it it in the first place did it, a unfortunately there are no strict rules regarding colours (for 2 way switching)

let me see i have this right.

you have 3 lights (one pair of two that both come on at the same time)

and a single light.

one set of lights can be turned on from either end of the kitchen and off at the other.

The other set of lights can only be turned on / off from the same place (as it not at both)

 

[mediamogul]

I have never seen the lights working - the house had been empty for a year when we bought it so I don't know exactly how the switching worked. You are right about the layout of the the lights I think ie a pair and a single.

Rachel

 

[mediamogul]

So no-one has any ideas? Any help would be really appreciated

 

[breezer]

that is not what i said.

I need more information, how many switches are there at each end?

it would appear that you have one 2 gang switch at one end and one single gang switch at the other, is this correct?

 

[mediamogul]

There are two 2 gang switches, one at either end. The first has two black/red and one 2 way cables and the second has one black/red and one 2 way cable. Maybe the second switch does not need to be 2 gang?

 

[breezer]

got it.

starting at the other end

put the yellow in common. the blue in L1 the red in L2

the other switch (same end) put the red in common and the black in L1


first end:

put the yellow in common red in L2 and blue in L1

here is the hard part
pick a red and black (same cable) and put one in L1 and the other in L2along with the red and blue respectively

Now you should have one cable (red & black left) put the red in common and the black in L1

you may have picked the wrong cable (red & black) so if it doesnt work swap the two twin cables over.

there is no g tee that this will work, but it looks like you can switch the following.

One set of lights from either end

one light from one end

a light some where else that can only be turned on / off from one end

unless of course that is why there are 3 lights

and turn the mains off before you do it.

 

[mediamogul]

Thank you! Will try it tomorrow and report back! Fingers crossed!

Rachel

 

[mediamogul]

Thanks for all your help.... unfortunately it hasn't worked. I've tried every combination possible and am having to resort to calling someone out. I will however stand and peer over his shoulder to see what the answer is and post it in case anyone else has this problem!

 

[breezer]

it will be interesting to know, the trouble is though, it really depends on how who ever installed it wired it as there is no standard "colours" for two way switching

 

[MANDATE]

Out of interest, did you establish whether or not the 'red' wires were in fact 'live', also did you establish whether or not the bulbs were ok,
assuming they were ok, could you not detach the two way 3 core cable and wire three switches as one way,( ie red to comm and black to L1,this would show which lights are controlled by which switch.
From your description you appear to have three circuits
One switch at either end linked by two way cable
One switch at either end wired as one way(no two way cable)
So ignoring the two way cable you should have 2 live reds at one end and 1 live red at the other end, if you have no 'lives' problem lies elsewhere (perhaps no live coming from previous ceiling rose).If you have 'lives' it is then easy to rewire the two way circuit.

 

[mediamogul]

I hadn't established anything... too scared to start fiddling around with meters plus I don't know what I'm doing! I'll try disconnecting everything and trying to establish what's what as per your explanation, as it's going to take a sparks about 10 days to get to me

Thank you everyone who is reading this and helping!

 

[MANDATE]

If you don't know what your doing you should not be messing around with live wires. Live wires must not be touched by hand, always use insulated instruments,also no not allow any live wires to touch the metal back box of a switch or any other wires. Although red wires are usually live you also have black wires that could be live in certain situations.
The same applies to the blue and yellow wires in two way switching.
Live wires that are not red should have a red sleeve fitted to indicate it may be live.
I feel you should have some 'hands on tuition and training' before attempting any electrical work on you own.

 

[mediamogul]

Thanks for your concern. I am not totally inexperienced, having run all the wiring for a 10 bedroomed country house from scratch. It's the diagnostic side I am not good at. I also isolate the circuits I am working on. I have no wish to go bang!

 

[mediamogul]

Right, I have sucess!!! Mind you, it took an electrician an hour to sort it so I don't feel so stupid! Breezer, you were right with the wiring in the switches - thank you very much. It was an incorrectly labelled black/ live wire which was causing the problem. The red sleeving had obviously come off at some point and had been put back on the wrong wire. I didn't stand a chance!

Thanks for all your input everyone