2 Way 2 Gang Dimmer Switch mess up

[stan633]

Right, this is the picture of the wiring, hope its not to big. Basically this was connected to a 2 way 2 gang dimmer switch, i took it out after it broke and left it for a while before noteing anything down. My mate had a go on the new one but pulled the wires apart, the two red ones on the left were intact and not touched. There was a red wire looped also. Basically this controlled 2 sets of different lights which were dimmable (and one could be switched on and off from downstairs) and one used the power to control light in the attic (which i GUESS was the looped wire), so 3 sets in total.

Might be a bit much to ask, but can anyone shed some light (excuse the pun) on how to wire it back up. I know there was 2 more sets of wires binded together as well as the red ones on the left..

 

[plugwash]

YUCK

wires just twisted together (you really should use terminal bock inside a backbox) and loads of cables

what did the switches control and was there any two way switching actually being used?

 

[stan633]

Hope i can explain this right. 1 Dimmer switch controlled 3 lights, one of which could be turned on and off from the switch downstairs.

Other dimmer controlled another light (which i use for my dartboard) and also can be turned on and off by seperate switch..

 

[plugwash]

i suspect the following then given that all the blacks are currently joined together (it seems they are in terminal block after all i didn't notice that the first time because its black)

the three and earth goes to the other switch for the dartboard light

one of the twin and earth cables brings power in

the other four twin and earth cables go to the lights (one via the switch you mentioned downstairs)

the first thing i would do i put each core into a seperate line of a long peice of terminal block to make them safe to work on

if you have a multimeter (if not get one a chape one will do fine for this) you don't need anything you can now use it on the appropriate ac voltage range to find out where power is coming in

once you have found which cable is bringing power in then you can use a short cable to connect it accross to each of the other twin and earth cables which should tell you which one goes to which light

once you know that the wiring should be pretty easy to figure out just remember a two gang switch is two seperate switches and how normal 2 way switching is done and it should be easy enough

 

[stan633]

Sorry for being an idiot.n Just want to know which wires goes into COM, L1 and L2 on the dimmer switch.

I know nothing about elecs and you've just fried my brain with that last comment.

Basicall what coloured wires are what??

 

[andy]

Sorry for being an idiot.n Just want to know which wires goes into COM, L1 and L2 on the dimmer switch.

I know nothing about elecs and you've just fried my brain with that last comment.

Basicall what coloured wires are what??

you tell me! look in the back of the other 2 way switch and wire it the same way as that (i.e if red is in com then put red in com etc)

 

[ban-all-sheds]

i suspect the following then given that all the blacks are currently joined together (it seems they are in terminal block after all i didn't notice that the first time because its black)

the three and earth goes to the other switch for the dartboard light

Or to the switch downstairs....

one of the twin and earth cables brings power in

the other four twin and earth cables go to the lights (one via the switch you mentioned downstairs)

I wonder how that works? There's only 1 3C+E, and none of the T/E can be a 2-wire strapper as all the blacks are joined together. I wonder if the red cores from 2 separate T/E cables are being used as strappers?

It would be interesting to know what's at the other switches. And I'd love to ask the guy who wired it WTF he was thinking...

the first thing i would do i put each core into a seperate line of a long peice of terminal block to make them safe to work on

if you have a multimeter (if not get one a chape one will do fine for this) you don't need anything you can now use it on the appropriate ac voltage range to find out where power is coming in

I suspect he'll also need to do continuity testing to identify the cores going to the non-3C+E 2-way switch..

Sorry for being an idiot.n Just want to know which wires goes into COM, L1 and L2 on the dimmer switch.

We can't tell you - there are too many unknowns, some of which can only be resolved by testing.

I know nothing about elecs

Then I'm afraid you have 2 choices:

1) Learn, pronto, buy a multimeter, find out what you've got and work out what to do

2) Call an electrician.

and you've just fried my brain with that last comment.

That's not very encouraging

Basicall what coloured wires are what??

Some are Live, some are switched live. Some go to the lights, some go to the other switches. The blacks are probably a mixture of neutrals and unuseds.

I'm afraid there is no simple "put this colour wire into this terminal" answer.

 

[stan633]

OK cheers, so im not going to blow anything up just using trial and error??

 

[andy]

possibly. if there are neutrals and you short a live to one, yes. if there are no neutrals, just lives and switched lives, the worst thatll happen is a light comes on if shorted

 

[ban-all-sheds]

There are no "loose" neutrals at that switch, nor are there likely to be any at the other ones, as light switches are single pole, so provided he leaves the blacks where they are, there won't be any short circuit issues.

But, stan633 - you have an unusual set-up, and you should work out what's going on by combining knowledge of lighting circuits and 2-way switching with testing - you'll go mad hoping to hit on the right combination by trial and error.

The only thing I can suggest you try is this:

First, you will have to look at the other switch for the dartboard light and the other switch downstairs, and see which one has the 3-core+earth cable and which one does not.

1) Put the red wire with tape on into a COM, and also link that to the other COM.

2) In one L1 put the two reds which are twisted together. At this point stop, turn the power back on and carefully check that you now have control of the two lights in the group of three that were not also controllable from downstairs. If you don't then my guesses have all run out. But assuming I'm right, then turn the power off again and...

3a) If the downstairs switch has the 3C+E, then into the same set of COM/L1/L2 terminals as you used in (1) & (2) put the red/yellow/blue of the 3C+E, making sure you get each colour in the same terminal as it's in in the downstairs switch.

3b) Put the remaining two reds into the other L1 & L2.

4a) If the dartboard switch has the 3C+E, then out the two reds into the L1 & L2 of the set you used in (1) & (2), and

4b) put the 3C+E into the other set of COM/L1/L2, again matching the colours with where they are in the dartboard switch.

If this doesn't work then I can't think of anything except you working out what is where with a multimeter or calling an electrician....

 

[stan633]

Does this seem right. Got a multimeter and tested, the following came up.

1) This is the power core that controls switch on/off downstairs.

2) Constantly live no matter if turn switch on dartboard or attic, same applies for (3) just constant power.

Other cores no power...

The downstairs switch has a red/blue, red/yellow cores into L1/L2

BTW its a Grade 2 listed building so god knows who done the wiring..

 

[ban-all-sheds]

1) This is the power core that controls switch on/off downstairs.

Not sure what you mean by that...

2) Constantly live no matter if turn switch on dartboard or attic, same applies for (3) just constant power.

Odd.

Other cores no power...

You're going to have to start applying power to them to see what lights come on.

The downstairs switch has a red/blue, red/yellow cores into L1/L2

Where do the reds come from?
Are these the same blue and yellow as the other switch?
What goes into the COM of the downstairs switch?

BTW its a Grade 2 listed building so god knows who done the wiring..

A colour-blind plumber on acid....

 

[stan633]

1) This is the power core that controls switch on/off downstairs.

Not sure what you mean by that...

Meant when i connected up multimeter, power came through when switch was tuned on downstairs, no power coming through when switched off..

1) COM wire coming from cable with other blue/yellow cable

2) 3 wires going into this L1 or L2. 1 red one coming from cable with earth core as you can see. Blue one obvious, the other red one coming from cable with earth and black core.

Christ, got upmost respect for you sparkies..

 

[Stoday]

It looks as though two reds and a blue go to L1 and a red and a yellow go to L2.

Is that right? I can't quite see.

 

[plugwash]

ok i think i've sussed it

connect the three and earth cable to the first dimmer (red to com yellow and blue to l1 and l2)

connect the permanently live red wire to the com terminal of the second dimmer

connect the remaining red wires to the l1 terminal of the second dimmer