Two Cables - Which one is the switch?

[markbramley]

Hi,

I am in the process of wiring up a new external light and have two cables containing 1 red, 1 black and 1 earth wire coming out of the wall. 1 is from the mains supply creating a ring circuit, the other a switch to turn the lamp on.

Does anyone know the easiest/safest way of telling which one is which before I start wiring up the new lamp??

Many Thanks

 

[Johnmelad502]

Hi,

I am in the process of wiring up a new external light and have two cables containing 1 red, 1 black and 1 earth wire coming out of the wall. 1 is from the mains supply creating a ring circuit, the other a switch to turn the lamp on.

Does anyone know the easiest/safest way of telling which one is which before I start wiring up the new lamp??

Many Thanks

Do you have a multi meter?

 

[londonboy]

Mark I told you how to do this in your duplicate post

 

[markbramley]

Hi,

I am in the process of wiring up a new external light and have two cables containing 1 red, 1 black and 1 earth wire coming out of the wall. 1 is from the mains supply creating a ring circuit, the other a switch to turn the lamp on.

Does anyone know the easiest/safest way of telling which one is which before I start wiring up the new lamp??

Many Thanks

Do you have a multi meter?

No unfortunately not, are they expensive?? Is there another way other than touching the wires ?

 

[Chri5]

Hi,

I am in the process of wiring up a new external light and have two cables containing 1 red, 1 black and 1 earth wire coming out of the wall. 1 is from the mains supply creating a ring circuit, the other a switch to turn the lamp on.

Ring it's not, it's a light circuit with just 1 LNE feed and 1 x switch cable.

I take it you haven't got any test equipment- a probe tester, a multi meter or anything else ?

If the cables are the same and they have on obvious way of differentiating between them, and you have no test tools then you are knackered.

Go buy a volt stick, they cost a £10 and that will tell you the cable which is live. As you know the switch wire carries the live up to and back from the light and has no current on it if the feeder LNE aren't connected.

 

[toasty]

Switch off the power.
Connect one cable to the lamp (ignore the other)

Turn the power back on. If the light comes on then that's the power cable. If it doesn't then it's the switch cable.

Easy, surely?
Hope this helps
Dan

 

[Johnmelad502]

Click here
http://www.wonderhowto.com/how-to-identify-switched-live-wire-lighting-circuit-261341/

 

[Johnmelad502]

Hi,

I am in the process of wiring up a new external light and have two cables containing 1 red, 1 black and 1 earth wire coming out of the wall. 1 is from the mains supply creating a ring circuit, the other a switch to turn the lamp on.

Does anyone know the easiest/safest way of telling which one is which before I start wiring up the new lamp??

Many Thanks

Do you have a multi meter?

No unfortunately not, are they expensive?? Is there another way other than touching the wires ?

Buy a multi meter, not a volt stick. You can then test with the power off. Volt sticks can be deceptive/dangerous if you are not familiar with them. A multi will cost around £10.00 from B&Q then follow the instructions in the video.

 

[MrMannering]

Buy a multi meter, not a volt stick. You can then test with the power off. Volt sticks can be deceptive/dangerous if you are not familiar with them.

Why?

 

[RF Lighting]

Because they can be too sensitive and illuminate on a 'dead' wire, or not sensitive enough and not light on a live wire.

 

[1john]

some of them can light up on almost anything. a proven multi meter is the best a DIYer can use without breaking the bank. has other uses such as continuity too.

 

[bongos]

Mark, you could buy yourself a mulitmeter from Maplins for as little as £7.

It is by far the easiest way of solving this problem and is a handy tool for having around the house for occassional use. Go on - treat yourself!

 

[ban-all-sheds]

A multimeter is as essential as screwdrivers.

Actually - it's even more essential, as you might sometimes be able to make do with the point of a knife instead of a screwdriver, but there's no way to make do without a multimeter.

his looks ideal for a household starter set - multimeter, voltage indicator and dedicated continuity tester, all in a handy case: http://www.amprobe.eu/de_DE/showproduct/115/Junior-Set/

PDF brochure: http://www.amprobe.eu/de_DE/downloadfile/115/beschreibung_1/

All in German, unfortunately, as is the blurb on each product:

Multimeter: http://www.amprobe.eu/de_DE/showproductdata/487/Hexagon_55/

Voltage indicator: http://www.amprobe.eu/de_DE/showproduct/116/2000_α_(alpha)/

Continuity tester: http://www.amprobe.eu/de_DE/showproduct/481/TESTFIX/

but it is sold in the UK - the company is now owned by Fluke, and I guess they haven't got all the websites sorted out yet - contact them (http://www.fluke.co.uk) for info on where to buy.

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