working out wiring in for new light fitting

[mastermiaow]

Hi

My bathroom light stopped working, I have replaced the bulb with no improvement. The old unit is no longer in supply so I will have to buy a new light fitting. I have put in light fittings before but am somewhat confused by the wiring coming out the ceiling I have looked at the Wiki but am still confused.
So there are three cables:
Cable 1 has a 1 black, 1 yellow-green and 1 red wire coming out.
Cable 2 has 1 black, 1 yellow-green, 1 red and 1 blue wire coming out
Cable 3 has 2 reds and 1 black coming out.
There is a single yellow wire coming out of the ceiling hole but which is not coming out of any cable.

All four reds are bonded together in a seperate connector.
The 2 yellow-green wires are bonded together with electrical tape.
Black from Cable 1 is bonded with yellow one half of another connector
Black from Cable 2 and Black from Cable 3 are with blue in other half of same connector. This connector was wired to the old light fitting although I forgot to note which way round the neutral and live wire from the old light fitting went in.

I have not bought the new light fitting yet but assume it will have seperate earth, neutral and live connectors. I assume that I put the green-yellow in the earth connectors but am unclear about the neutral and live configuration?

I am attaching photos. Apologies for quality. Hope you can help

 

[ban-all-sheds]

The old unit is no longer in supply so I will have to buy a new light fitting.

And the reason you know that the fitting is faulty, and not the switch, or any of the wiring is.....?

I have put in light fittings before but am somewhat confused by the wiring coming out the ceiling I have looked at the Wiki but am still confused.
So there are three cables:

Have you used your multimeter yet to identify the switch drop, permanent live(s) etc?

Cable 1 has a 1 black, 1 yellow-green and 1 red wire coming out.
Cable 2 has 1 black, 1 yellow-green, 1 red and 1 blue wire coming out
Cable 3 has 2 reds and 1 black coming out.

#2 and #3 are very odd combinations - you're sure they aren't sleeved those colours? #3 is of particular concern - could be twin & earth with the earth used for something else.

There is a single yellow wire coming out of the ceiling hole but which is not coming out of any cable.

All four reds are bonded together in a seperate connector.

Probably permanent lives.

Loop in, loop out, switch, and... Do you have a fan worked by the light switch?

The 2 yellow-green wires are bonded together with electrical tape.

Naughty - should be a proper connector. And does the light not need an earth?

Black from Cable 1 is bonded with yellow one half of another connector

Check to see if that's switched live.

Black from Cable 2 and Black from Cable 3 are with blue in other half of same connector.

Check to see if that's neutral loop in, loop out and... Do you have a fan worked by the light switch?

I have not bought the new light fitting yet but assume it will have seperate earth, neutral and live connectors.

It may or may not have an earth terminal.

I assume that I put the green-yellow in the earth connectors but am unclear about the neutral and live configuration?

Same as the old light.

I am attaching photos.

No you're not.

 

[Johnmelad]

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• mastermiaow
• 27 Sep 2012
• 1

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• mastermiaow
• 27 Sep 2012
• 1

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• mastermiaow
• 27 Sep 2012
• 1

 

[ban-all-sheds]

So WTH didn't mastermiaow bother to follow the instructions?

Anyway - it's academic - I know I'm overdue for a sight test, but I don't think that's why I can't make out anything useful from those photos.

 

[mastermiaow]

First of all thanks Johnmelad for the photos that I thought I uploaded - not quite sure what happened there....
And thanks ban-all-sheds: you clearly know what you are talking about! So to answer:

And the reason you know that the fitting is faulty, and not the switch, or any of the wiring is.....?

The pull switch operates light and a seperate fan which is situated on a wall. Fan is working so switch must be. You're right - I am not sure about the wiring. I don't have a multimeter just a screw driver which tests for live which I have never used!

Have you used your multimeter yet to identify the switch drop, permanent live(s) etc?

My knowledge is basic about this. I was hoping to get away with replicating the existing wiring arrangements with the new fitting.

#2 and #3 are very odd combinations - you're sure they aren't sleeved those colours? #3 is of particular concern - could be twin & earth with the earth used for something else.

This is slightly alarming. I am not sure about this but could it be that having a fan explains the configuration?

Black from Cable 1 is bonded with yellow one half of another connector
Check to see if that's switched live.
Black from Cable 2 and Black from Cable 3 are with blue in other half of same connector.
Check to see if that's neutral loop in, loop out and..

This sounds better - it's what the old unit was connected to so if I wire up the new unit live to black and yellow and neutral with the two blacks and blue and it doesn't work, I'll know the problem is the wiring not the unit. - right?

The 2 yellow-green wires are bonded together with electrical tape.
Naughty - should be a proper connector. And does the light not need an earth?

The existing light unit did not have an earth - I assume the new unit will have and I put the the 2 yellow-green wires currently bonded together into the earth socket of the unit?

Many thanks again

Matthew

 

[ban-all-sheds]

The pull switch operates light and a seperate fan which is situated on a wall. Fan is working so switch must be. You're right - I am not sure about the wiring. I don't have a multimeter just a screw driver which tests for live which I have never used!

Throw that in the bin, unless it's useful as an actual screwdriver (most aren't).

They are unreliable as testers - you really should have something with 2 poles, at least a multimeter. IF you want to work on your electrics they they are as essential as the screwdrivers and wirecutters etc you'll also need.

This 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.

Right now the English specs are still lurking on the Internet Time Machine from when Beha was an independent company:

http://web.archive.org/web/20060920022629/http://www.beha.com/files_uk/multimeter/93549.pdf


Also see another discussion here: //www.diynot.com/forums/viewtopic.php?t=26282 It's a few years old, so specific model number advice may be obsolete (and prices will be higher), but the generic advice is still sound.

My knowledge is basic about this. I was hoping to get away with replicating the existing wiring arrangements with the new fitting.

I thought you said you hadn't made a note of how the old one was connected up...

This is slightly alarming. I am not sure about this but could it be that having a fan explains the configuration?

Having a fan explains a lot, but does not lead to misuse of cores.

Have a look at what's at the fan.

Is all the wiring in the loft, and traceable?

This sounds better - it's what the old unit was connected to so if I wire up the new unit live to black and yellow and neutral with the two blacks and blue and it doesn't work, I'll know the problem is the wiring not the unit. - right?

You could do that test with a lampholder on a bit of flex before buying a new light.

What sort of light is the existing one?

I assume the new unit will have and I put the the 2 yellow-green wires currently bonded together into the earth socket of the unit?

Assuming they are actually earths.

But there's too much assuming going on here for my liking - some sound identification of conductors is needed.

 

[mastermiaow]

Thanks again for your recommendations. I need to fix this asap as I have a lodger and it's already been a few days that we are brushing our teeth by candlelight. I haven't really got time or energy to master how to use continuity testers etc So I'd thought I'd have a go by wiring up a new fitting and if it doesn't work get a sparky in. Perhaps this was overly ambitious...

I thought you said you hadn't made a note of how the old one was connected up..

Can't I just test that by wiring up the new light fitting? There is a 50% chance that it is right e.g. black and yellow combination is live and two blacks with blue combination is neutral or the other way round. Or is there a danger that wiring a live to a neutral will blow the electrics?

Have a look at what's at the fan.

Is all the wiring in the loft, and traceable?

Doubt I can trace it. Even if I could, I don't think i have the knowledge and skills for this sort of indepth electrics.

What sort of light is the existing one?

Just for a bog standard screw in bulb - 240v/42w. I threw the old light fighting away When I took it to my local hardware store, he said it is quite common for fittings to fail, it is made by Cascade and seemed quite old.

I assume the new unit will have and I put the the 2 yellow-green wires currently bonded together into the earth socket of the unit?
Assuming they are actually earths.

I thought green and yellow wires were earths? Or do you think they could have been wrongly sleeved?

Thanks again for any advice

Matthew

 

[ban-all-sheds]

Or is there a danger that wiring a live to a neutral will blow the electrics?

The light will work fine either way around.

I thought green and yellow wires were earths? Or do you think they could have been wrongly sleeved?

They should be earths. They probably are. But wires have no understanding of what they should be used for, and anybody can put any colour sleeving on anything.

Given that there is a possibility ("Cable 3 has 2 reds and 1 black coming out") that a numpty has been there and a core meant to be used only as an earth is being used for something else (and sleeving the bare core of twin & earth to use it for something else is not OK), I can't say with certainty that your G/Y ones are earths and could safely be connected to the earth terminal of a light.

Short term solution would be to buy a new light which doesn't need an earth, but longer term you should get an electrician in to check if everything is kosher.

 

[mastermiaow]

I had another look at the wiring because of what you wrote. I made a mistake All three cables have one red, one black and one yellow/green. There is a blue, a yellow and a red sleeved wire that are not cabled and go up through the hole above the ceiling.
Two of the yellow green wires are then sleeved together and bonded with the third in a block.
Given the above, does it make the wiring more explicable and less dangerous?
Can I now I buy a light fitting with an earth - it will be hard to know if it has one until I open the package..

Many thanks again and sorry for misinforming you the first time round!

 

[ban-all-sheds]

So you've got 4 cables?

3 red/black twin & earth, and 1 red/blue/yellow 3-core & earth (which appears to have had it's earth core cut back)?

That's what would make the most sense:

//www.diynot.com/wiki/electrics:fan


Lights which don't need an earth will be marked with the double insulation symbol, both on the item and on the outside of any packaging.

 

[mastermiaow]

I have 3 cables and three wires which are not in a cable. The three wires without a cable are a red, a blue and a yellow. They are seperate wires. I thought the yellow was another earth but from what you say I understand that normally there would also be another earth wire which has been cut back. Anyway things seem to be falling into place
However if I can't get hold of a light that doesn't need an earth, is it OK to use one that does and put the three yellow/green wires in the earth socket of the new light fitting?

Thanks again for your patience and help

 

[ban-all-sheds]

The three wires without a cable are a red, a blue and a yellow. They are seperate wires.

Or it's 3C+E with the sheath cut back a long way.

However if I can't get hold of a light that doesn't need an earth, is it OK to use one that does and put the three yellow/green wires in the earth socket of the new light fitting?

Should be, if all is as it should be.

 

[mastermiaow]

Hi

I wired the fitting in on Monday. The main problem was getting the three 'neutral' and four 'earth' to fit in sockets made for one. The other problem was that the wires were not long enough. In the end I got them in but there was exposed copper as can be seen from

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• mastermiaow
• 4 Oct 2012
• 1

I went back the next day and wired in two junction blocks for neutral and live and covered them with insulating tape:

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• mastermiaow
• 4 Oct 2012
• 1

However the earth wires are still exposed down to the copper. Is that dangerous?

 

[ban-all-sheds]

It's a mess, and the connections are probably dodgy - the earths are certainly unacceptable.

Take it down and do it again - fix a 4-way strip of choc-block to the body of the light, as far away from the lamp as possible, take all the circuit cables to that and then just 3 connections to the light.

Did it come with any heat-resistant sleeving?

 

[mastermiaow]

OK - how would you fix the choc blocks to the light fitting - with insulation tape or something else like glue? I assume I use the heat resistant sleeving on the single 'extension' wires going into the light fitting (I will have to buy some more of the stuff as it got wasted in my attempt to fit all the wires into the light sockets)