Outside Light

[rogers_danny]

Hi,

Hope someone can help me here.

Recently moved into a brand new house. The electricians have put a small box on the outside wall which contains wire for an outside light. I have put a 500W Halogen light up with PIR detector, I have put the wire into the light using a 1.5mm 2 core with earth, standard blue and brown cable.

When I came to join this up with the wire in the box I have noticed this is a 3 core and earth cable, the colours are Black, Brown and Grey...

Does anyone know what goes where?? I have the earth sorted!

There is a 2 way swicth in the kitchen that controls the outside light as well as my kitchen light.

Please help??

Thanks
Mr Rogers

 

[ban-all-sheds]

Why not use your multimeter to identify which core is which?

 

[rogers_danny]

I don't own a multi meter.

I thought there would be a standard colour they would be required to use for neutral/live etc..

i.e. Blue = Neutral
Brown = Live (in standard wiring)

Because there is brown,black and grey I'm completely thrown.

Would there not be an obvious answer to this or would an electricaln just randomise the colours when wiring?

And what about the spare wire?

 

[ban-all-sheds]

I don't own a multi meter.

Do you own a hammer for dealing with nails, or do you use the heel of a shoe?
Do you own a screwdriver for dealing with screws, or do you use the point of a knife?
Would you expect to be able to overhaul a car engine without having spanners and sockets?

I'm not trying to be funny - it's all about possessing the correct tools for the job, and if you are going to do anything with electricity beyond flicking a switch to make things work, you should have a multimeter.

I thought there would be a standard colour they would be required to use for neutral/live etc..

There isn't with 3-core & earth cable, and there never was before the colour change from red/blue/yellow. There are and were common conventions, but nothing you would stake your safety on.

i.e. Blue = Neutral
Brown = Live (in standard wiring)

Because there is brown,black and grey I'm completely thrown.

http://www.niceic.org.uk/downloads/WiringSupp.pdf

Would there not be an obvious answer to this or would an electricaln just randomise the colours when wiring?

No - in a single-phase environment he would probably use brown for permanent live, and avoid the use of black for neutral. One thing I can absolutely guarantee though is that if presented with a cable that he hadn't installed he would inspect and test it to see which core did what.

And what about the spare wire?

How do you know that it is spare? How do you know that you haven't got permanent live, switched live and neutral?

As I see it you have 3 choices.

1) Trial and error (I leave you to decide how sensible an idea that is)

2) Get a multimeter

3) Get an electrician

Nobody here has extrasensory powers - we cannot say what the function of each core is.

 

[rogers_danny]

Firstly I'm not the kinda person who hits nails with shoes etc.

I stumbled across the site and thought I may be able to get some sort of help, it's only 3 wires and I feel that paying for an electrician to wire a light is a bit over the top. I wouldn't try and wire it back to the switch or dig through walls etc.

I am comfortable wiring new light fittings etc.

The only other info I can give is that I've had a look at the switch that would control this cable.

This is a double switch that also controls my kitchen lights.

The layout is as follows:

Top section: from left to right
L1 = 3 Brown wires
L3 = 2 Brown & 1 Black
L2 = 1 Brown & 1 Grey

Bottom Section: from left to right
L3 = EMPTY
L2 = 1 Black with Brown sheath
L1 = 1 Brown

The Blue Cables are in the bottom of the wall box wired together in a connector block.

If anyone can provide info that might help me then thanks.

 

[ban-all-sheds]

Firstly I'm not the kinda person who hits nails with shoes etc.

So you've got a multimeter then - excellent

I stumbled across the site and thought I may be able to get some sort of help,

Help yes, clairvoyance no.

it's only 3 wires

But which 3?

and I feel that paying for an electrician to wire a light is a bit over the top.

So you don't know which wire is which, you can't or won't use your multimeter to find out, but you don't think you should pay for someone who can do it?

The only other info I can give is that I've had a look at the switch that would control this cable.

This is a double switch that also controls my kitchen lights.

The layout is as follows:

The switch has a left and right half, each half has 3 terminals, L1, L2 & L3, arranged in a triangle. On the RHS the triangle is inverted.

So the grouping of each L1, L2 & L3 is:


[code:1] L1 | L3 L2
|
|
L3 L2 | L1[/code:1]
L1 are the commons, and L2/L3 the alternate terminals connected to L1 by the switches.

The fact that you have a bunch of blues connected together means that your lighting circuit is looped through the switches, rather than at the ceiling fittings, so...

Top section: from left to right
L1 = 3 Brown wires

Probably permanent lives

L3 = 2 Brown & 1 Black

The black might be the one that ends up outside - use your multimeter to find out.

L2 = 1 Brown & 1 Grey

The grey might be the one that ends up outside - use your multimeter to find out.

Bottom Section: from left to right
L3 = EMPTY

OK - so this switch ( the right hand one when viewed from the front is used as a 1-way.

L2 = 1 Black with Brown sheath

Probably the switched live that goes to the light that this switch works.

L1 = 1 Brown

Permanent live? One of the cores of a 3-core + earth cable that runs to another switch to make it 2-way? Does this switch (the left one when in use) do anything? Is it one half of a 2-way switching circuit?

A big help would be to know which cores are permanently live (use your multimeter) and which ones are from the same cable.

The Blue Cables are in the bottom of the wall box wired together in a connector block.

If there's nothing but blues there, then either there is something else going on elsewhere that you have not found yet, or you have no neutral coming out of the wall, which means a light won't work.

If anyone can provide info that might help me then thanks.

As I see it you have 3 choices.

1) Trial and error (I leave you to decide how sensible an idea that is)

2) Investigate further to find how/where you get a neutral appearing outside, and use your multimeter to identify and trace cables

3) Get an electrician

 

[Ruggie]

I had the same problem in my new place. I brought a neon tester screwdriver and found one is a constant live, one the switched live and needless to say the other two netural and earth.

With the neon tester I could determine the switched live (also look at the back of the switch?) and the constant live.

I think it is done this way so you can 'over ride' the PIR with the switch and have the light on constant when you are outside without having to jump around like a fool.

 

[ban-all-sheds]

Throw your neon tester away and buy a multimeter or proper voltage indicator!

Take a look at this: http://www.beha.com/files_d/sets/1333.pdf

Looks ideal for a household starter set - multimeter, voltage indicator and dedicated continuity tester, all in a handy case.

Couldn't find details of the set in English, but all 3 individual instruments are listed.

http://www.beha.com/files_uk/multimeter/93549.pdf

http://www.beha.com/files_uk/voltagetesters/6741.pdf

http://www.beha.com/files_uk/continuitytesters/9023.pdf


Also see the full discussion here: //www.diynot.com/forums/viewtopic.php?t=26282

 

[Qedelec]

Please don't take this the wrong way, saving lives is more important than being polite, BUT, any one who uses a neon screwdriver to test for voltage is a FOOL.

For the uninitiated reading this site, the use of a neon screwdriver involves using your body as a path to earth with a small resistor to protect you from mains voltage. Who but a fool or the ignorant would use their body as part of a mains circuit.