electrical problem (dimmer on 2-way light switch)

[sonia41]

Hi

I have a 2 gang 2 way light switch & want to fit an electronic dimmer, the wiring inside are 2 red wires, 1 black, 1 blue, 1 yellow and the green/yellow I'm guessing this is the earth is wired to the metal box in the wall. On the dimmer there are the symbols L (2 of them) Sw and the two crossed arrows which I'm guess is the common don't know what Sw means. Now I'm guessing that the red wires go in the L terminals on the dimmer but don't know where I should put the other wires. Also on the dimmer to the right is another terminal but it's not labelled I'm also guessing that this is where the earth wire would go but as the earth is attached to the metal box I would not need to use this.

 

[ban-all-sheds]

I have a 2 gang 2 way light switch & want to fit an electronic dimmer, the wiring inside are 2 red wires, 1 black, 1 blue, 1 yellow

On the face of it that sounds like a normal twin & earth drop cable to one side of the switch, and a 3-core & earth strapper cable from another switch somewhere - does one side of the existing switch work as one of a pair of two-way switches?

and the green/yellow

Two of those, I hope.

I also hope that you made a very careful note of which wire went where, or that you will do before you remove the old switch...

On the dimmer there are the symbols L (2 of them)

Probably the permanent live feed, but surely the instructions tell you?

Sw

Two of those, I hope. Probably the switched outputs to use if you've got 2-way switching. If you have, BTW, will you be happy with only being able to control the brightness from one place?

and the two crossed arrows which I'm guess is the common

If it's a wavy line with an arrow through it it's probably the dimmer output, but the instructions will tell you.

don't know what Sw means. Now I'm guessing that the red wires go in the L terminals on the dimmer but don't know where I should put the other wires.

Stop guessing, read the instructions, look to see which wires go where on the existing switch, and learn about how light switches are wired, particularly 2-way ones, by reading the articles in the Wiki and the For Reference section. Once you understand that, and can see what goes where in the switch you'll be able to easily identify your wires and be able to follow the instructions.

Also on the dimmer to the right is another terminal but it's not labelled I'm also guessing that this is where the earth wire would go but as the earth is attached to the metal box I would not need to use this.

Stop guessing - that's an unsafe way to do electrics. Is it really unmarked? No earth symbol etched or stamped onto the back of the dimmer nearby? Is it a metal dimer?

If it has an earth terminal you must connect both the earth wires into it, and you should run a short length from there to the back box.

 

[ban-all-sheds]

Thanks for your reply,I haven;t as yet removed the existing switch its wired in the sequence of red,red,blue at the top. black & yellow at the bottom.

The first red goes with the black, and that's the 1-way side of the switch.

The red, blue and yellow are on the 2-way side and run to the other 2-way switch.

Your switch has 3 terminals at the top and 3 at the bottom, arranged

COM L1 L2

L1 L2 COM

(or a mirror image), but they are grouped in the form of 2 triangles, one inverted - see this: //www.diynot.com/forums/viewtopic.php?p=305498#305498

So you need to transfer the wires to the appropriate terminals in your dimmer switch.

And yes one of the switches works two ways I also have a single switch near my garden door. Both the 2way & single switch have a single green/yellow wire which is secured the metal box that is fitted into the wall.

You are missing one earth wire at the 2-gang switch - both cables should have one.

The dimmer has a metal back & a plastic face slots onto it, it's a screwless flat plate. the terminal on the right does have 3 lines if this means anything

Yes, it's the symbol for earth, it must be connected to the two earth cores in the two cables.

So you didn't recognise the symbol for earth, and if you hadn't posted here you'd have gone with this notion:

Also on the dimmer to the right is another terminal but it's not labelled I'm also guessing that this is where the earth wire would go but as the earth is attached to the metal box I would not need to use this.

I really think you should spend some time learning about electrics before you start to fiddle with them....

I did get a council electrician in & he wired the dimmer switch in the sequence
L = red Arrow symbol= black in the next box terminal, L=red, Sw=blue Arrow=yellow. It may have been my imagination but he didn't seem to know what he was doing.

So did it not work? And how does that square with "I haven;t as yet removed the existing switch"?

And I have looked at the instructions & it shows one of the red wires in the common terminal a blue or black in L1 & in the other terminals a red & the neutrals in the Sw & arrow symbol so if this is the case where would the yellow go and why does it say in the instructions not to connect the dimmer terminal marked Sw to neutral if it shows it in the diagram.

Black is not neutral.

Blue is not neutral.

Yellow is not neutral.

Each of the wires will be live at one time or another.

I really think you should spend some time learning about electrics before you start to fiddle with them....

As a women I can do most things when it comes to a mans world but the electrics is one that I don't fully understand but I did wire up all the other switches in my home & they're ok.

Women's brains are just as capable as men's - there's absolutely no reason why you can't understand it.

I notice that on the diagrams they talk about the red wire =live the black and blue=neutrals the green/yellow=earth but what about just the yellow wire diagrams hardly mention the yellow.

Black is not neutral.

Blue is not neutral.

See the diagrams of 2-way switching in For Reference - there are several - they show red/blue/yellow....

 

[ban-all-sheds]

I'm not sure if this is what I think about.

And I'm not sure that you and thinking are on close terms:

1. This is a UK forum, and you are in the USA. Your cable colours are different from ours, your voltage is different from ours, your supply types are different from ours, your wiring practices are different from ours and your terminology is different from ours.
   
   
2. Even though your domestic voltage is not 230V, it isn't 12V either, so how on earth would any sort of car electrical accessory be suitable?
   
   
3. This topic is over 2 years old.
   

 

[Taylortwocities]

Makes you wonder how they managed to put anybody on the Moon.


Oh, I hope I'm not going to get slapped for racial abuse, again..