wiring of double dimmer switch

[simba1903]

I am wiring a double dimmer switch, which was taken off by a decorator and replaced and now we seem to have a problem with a circuit of the lights in 1 room so I am trying to identify the problem starting by making sure the switch is not at fault.
I have attached a picture of the switch how it is connected does it all seem right? One picture shows the wires coming into the back box and the other picture showing the connections on the switch.
There are 2x (2 core + a bare wire?) The two bare wires are both connected to the metal back box.
I might also trying wiring it up to a standard double switch and to check if the problem is the switch itself, the wiring should be the same with a standard double switch and a dimmer double switch?




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[riveralt]

Put one of the two reds into L1 on the first switch and L1 on the second switch. Put the red link between the two L1's. This is you power in.
(I cannot see the third terminal but if it is C then put each cable into their respective C terminals and run the link between.)

Put one of the two blacks(with red sleeves) from the same cable as one of the reds into L1 if there is a C terminal and the other one into the other switch L1. If no C terminal then put them into L2.

If you have energised the circuit the way you have wired it currently you may have damaged the dimmer - you certainly have cracked the rear plastic protector.

 

[simba1903]

Thank you for the reply it is very helpful.
I did not understand:

''(I cannot see the third terminal but if it is C then put each cable into their respective C terminals and run the link between.)''

With your explaination the wires are all used..
1 live and neutral from the same wire to L1
1 live and neutral from the same wire to L1 on second switch
link between L1s

Please can you clarify what the sentence in brackets as its confuzed me.
ps the 3rd terminal is C




Thanks

 

[EFLImpudence]

If it is two switches which operate two lights independantly then

you should have one cable to each switch.

At each switch connect the Red (live) to L1 and
the Black with red sleeve (switched live - NOT NEUTRAL) to C

I cannot see why you would want a link so try that without it first.

 

[securespark]

Is it the RH switch not working?

 

[simba1903]

I have tried connecting as EFLImpudence have suggested.
I took a picture of the arrangement to be sure.
This arrangement has not worked and neither circuits now are lit.


image hosting sites

I cannot remember unfortunatly which dimmer was the one which was originally working.

Does it depend on the wiring how these are wired sometimes or are they always wired the same I am only thinking this as so far I have had 2 different suggestions + the wiring was wired differently to begin with as in my first picture.

Thank you for the replies

 

[EFLImpudence]

Do you have an ordinary switch you could use?

You can try one cable at a time to see if it works.

Please confirm that it is two switches which operate two lights independantly

 

[simba1903]

Yes I have another double switch I will try with it tomorrow.
Thanks for the suggestions.
Yes the two switches operate 2 circuits independantly. Is it called a ring not circuit though? . There are 2 lights on 1 ring. and 3 on the other.
We have redesigned/decorated and have decided to loose 2 lights, 1 from each ring. The wire was cut off and covered with tape.

 

[EFLImpudence]

Is it called a ring not circuit though? . There are 2 lights on 1 ring. and 3 on the other.

No, it's not a ring.
It's a radial - a line or a line with branches.

We have redesigned/decorated and have decided to loose 2 lights, 1 from each ring. The wire was cut off and covered with tape.

Not the way to do it and you may have removed the supply to the other light or even both depending on where you have removed the wire.
If there was only one cable at each of the lights you have removed you may be lucky and not altered anything.

See here
//www.diynot.com/wiki/electrics:lighting:lighting_circuit_layouts
and understand how it works.

 

[EFLImpudence]

quote instead of edit

 

[securespark]

Join each pair of wires up, with one pair in one terminal on one switch and the other pair in one terminal on the other switch.

This gives the same effect as closing a normal switch. If both light fittings are operational and your wiring intact, they should come on.

But what bothers me slightly is that link. You've a short link there, as if it has always existed, before the problem. This implies that the commons should be linked.

Are you POSITIVE that one of the switches was not one of a two way with another switch somewhere else?

If that were the case, that could explain the link wire. One twin and earth wire would carry the live feed and the switchwire to the light with one switch. The live feed would go to common of the switch you wanted to operate this light, along with the short link. The black with red tracer of this cable would go to L1.

The short link would go to common on the other switch and then the other twin and earth would connect to L1 and L2 of that switch. These wires would then link up with the other switch controlling that light.

This is only a suggestion, but it is one explanation for the presence of the short link wire.

 

[simba1903]

you may have removed the supply to the other light or even both depending on where you have removed the wire.

I can't figure how cutting the wire back may affect the electrics.

Join each pair of wires up, with one pair in one terminal on one switch and the other pair in one terminal on the other switch

I have tried using a standard double switch and connected a black and a red from the same cable, no lights are lit.

When I measure each pairs I get 10V on one pair and nothing on the other.
After this I (I know your not suposed to) touched the wires one by one, no current, should there not be 120V to here?

Are you POSITIVE that one of the switches was not one of a two way with another switch somewhere else?

There are no other switches which operate these lights its just the double dimmer switch

 

[riveralt]

you may have removed the supply to the other light or even both depending on where you have removed the wire.

I can't figure how cutting the wire back may affect the electrics.

If the cable you cut back and put in tape was the cable bringing the power to the ceiling rose then it doesn't matter how much you fiddle with the switch the light at that ceiling rose will never work.
If you look at the wiki page you were directed to by EFL you can see that if in that example you cut the power cable between the kitchen and dining room - the dining room light would never work.
I'm afraid that you are at the point where unless you fully understand how lighting circuits work and you fully understand how your lighting circuit has been wired then no end of moving cables around the switch will work.
Perhaps its time to call in an electrician to sort it out for you.

 

[ban-all-sheds]

I can't figure how cutting the wire back may affect the electrics.

Have you done this yet?

See here
//www.diynot.com/wiki/electrics:lighting:lighting_circuit_layouts
and understand how it works.

When I measure each pairs I get 10V on one pair and nothing on the other.

What voltage would you expect to see between the two conductors of a switch cable?

After this I (I know your not suposed to) touched the wires one by one

What do you mean "touch"?

And why are you doing things with electricity which you know you aren't supposed to?

no current, should there not be 120V to here?

Why 120V?

120V between which two points?

Basically there is Plan A, and there is Plan B.

PLAN A:

• Learn how lighting circuits are wired.
• Get a multimeter and learn how to use it.
• Identify which conductors are which at the switches and the light positions.
• Check for voltage present, circuit continuity, switches working etc.
• Connect everything up properly.

PLAN B:

• Get an electrician.

Just trying different things hoping to luck on the right combination is foolish. You should NOT be following instructions to put-this-wire-in-that-hole without actually understanding why.

 

[securespark]

How long have you lived in the house?

Which lights are operated by the switches?