# Forum Home Renovation Lighting  Light Switch

## Sid

Hi All, i am trying to replace a single switch light switch (clipsal) because the the old one is broken, i took the wires out of the old one and didnt really see what came from where (i know, idiot) and i dont know which is the live and which is the neutral, years ago there was an L (for live) and an N (for neutral) please help or i will have to call an electrician which will cost a small fortune for something that should be so simple :Smilie: 
Cheers, Sid

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## chrisp

How many wires are there, and what colour are they?

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## Sid

> How many wires are there, and what colour are they?

  Hi Chrisp, there are 3 wires, red, black and green but there are 4 places to put them on the swithch, there is one that is shaped a bit different and i guess (but i'm not sure) that is the earth, from the other 3 others i dont know which is which.
cheers, sid  :Smilie:

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## applied

I forecast sparks in your future.

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## chrisp

> Hi Chrisp, there are 3 wires, red, black and green but there are 4 places to put them on the swithch, there is one that is shaped a bit different and i guess (but i'm not sure) that is the earth, from the other 3 others i dont know which is which.
> cheers, sid

  Sid, 
You have something strange there. 
Usually, for a single light-switch, you will have either: (a) a single cable with a red and a white wire; or (b) two cables - each with red, black & green. 
There can be variations on the above when there are multiple switches and/or multi-way switching involved. 
Without seeing how that 3-core cable is connected in to the rest of the installation, it is hard to provide remote advice.

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## tricky4000

SId, you should get a sparky mate, especially if you're not sure.  The wiring sound non standard, I wouldn't risk it.

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## Kevin_Baker

I'd suggest you actually upload a photo, might be able to help out more actually seeing the wiring config!

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## Bros

> The wiring sound non standard,

  Not really there was nothing to stop you using twin and earth for switch wire. Be interesting to know if the earth is connected at the other end.  
You can do the same now except you have to sleeve the black to red.

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## chrisp

Another option is to open up another switch and have a look to see if the same cable has been used. If so, you'd get an idea of the convention that has been used. 
Caution is recommended.

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## GeoffW1

> Not really there was nothing to stop you using twin and earth for switch wire. Be interesting to know if the earth is connected at the other end.  
> You can do the same now except you have to sleeve the black to red.

  Hi, 
But the code would surely not allow you to actually connect the earth wire (still  assuming it is not connected to earth at the other end) to voltage at the switch? Even if it was very convenient to do so? 
There is no normal role for earth connections at the switch I think? 
Cheers

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## Bros

> But the code would surely not allow you to actually connect the earth wire (still  assuming it is not connected to earth at the other end) to voltage at the switch? Even if it was very convenient to do so?

  From what I have seen in the past there seems nothing to stop you connecting to the looping terminal of the switch. I asked an inspector about this many years ago and he said he would like to see it terminated in a BP connector and taped back on the sheath.   

> There is no normal role for earth connections at the switch I think?

  None whatsoever it was just done for convenience to save carrying around another roll of cable.   

> 5.4.3 Lighting points
> A protective earthing conductor, connected to a terminal or suitably
> insulated and enclosed, shall be provided at every lighting point, including
> transformers supplying ELV lighting systems.

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## Sid

> Sid, 
> You have something strange there. 
> Usually, for a single light-switch, you will have either: (a) a single cable with a red and a white wire; or (b) two cables - each with red, black & green. 
> There can be variations on the above when there are multiple switches and/or multi-way switching involved. 
> Without seeing how that 3-core cable is connected in to the rest of the installation, it is hard to provide remote advice.

  Hi Chrisp, there are two cables, each with red, black and green, i guess one comes from the power and the other goes to the light but without opening up the wall i cant see that. The 2 green are twisted together as are the 2 red and the 2 black, i just dont know which conectors in the switch to conect each one too, i have tried to attach a photo of the back of the swich but having just started to use this site i'm not shur how to do that yet, if the photo is not there i'll try to do it later. 
Cheers, sid

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## Bros

2 Greens the plot thickens

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## Master Splinter

I hate to say it, but if you can't figure out a switch mechanism and confirm its operation with a multimeter, you shouldn't be playing with it. 
There's a 70 page document in my signature that contains all the info you need to know, and/or look here: Silicon Chip Online - House Wiring: Looking At Light Switches

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## China

I hope your fire insurence is up to date

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## Sid

> I hate to say it, but if you can't figure out a switch mechanism and confirm its operation with a multimeter, you shouldn't be playing with it. 
> There's a 70 page document in my signature that contains all the info you need to know, and/or look here: Silicon Chip Online - House Wiring: Looking At Light Switches

  Thanks for that everyone, especially chrisp and master splinter, both very helpful, i guess the best thing to do is get a sparky in, its worth the peace of mind.  :2thumbsup:

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## Rustynuts

Hi Sid
I reiterate - you shouldn't be touching it.
Under no circumstance does the green get connected to the switch. It should be either soldered and taped or a double screw insulated connector used and taped.
If all the colours are joined to their like colours by being twisted then it sounds like you could even have a wire missing. The switch wire, which is likely to be a single double insulated red or black cable.
My advice would be to try and trace the wires as to where they finish up. 
The terminals in what you describe as a Clipsal 30m series has the terminals marked if you look closely.
The 'D" shaped terminal does nothing except being provided as a looping terminal and usually neutrals are joined in this terminal.
The one in the centre is marked 'C' for 'Common' and is normally for the active ( live) red.
'1' is for a switch wire running up and terminating in the light.
'2' is used only if you have '2 way' control over the light from different locations.
A qualified sparky sounds like possibly your cheapest solution and should be only a service call. Far cheaper than a fire or someone being electrocuted.

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