Lighting Problem...

[KentGull]

I had to put a new ceiling in the bathroom so took down the lightfitting which was covered in Artex and old paint and decided to replace it. I've rewired the new fitting according to the instructions... now I have no lighting upstairs at all. I've checked the fuses - they are all OK. I've double checked the wiring against the instructions supplied. I've tried replacing all the bulbs upstairs (drastic I know). Anybody out there with any ideas?

There are two mains leads coming into the fitting and one switch lead (3 in all). All the earths have been wired together (as per instructions). All the earths have been wired together - loop (as per instructions). The two neutrals have been joined to the lamp cable neutral and the switch neutral has been joined to the live lamp cable. All this is as per the instructions.

Am I doing something so obviously wrong? help! It's dark up here!

 

[Big_Spark]

Kent, it would appear that you have miswired the fitting in some way.

Breezer or Ban will be along soon, they have some rather snazzing images of circuits that will show you, in colour, how the fitting should be wired.

In the meantime read this.

FIRST ENSURE THE POWER TO THE LIGHTS IS OFF

Your fitting has Three cables coming into it, One a feed in, One a feed out, and one a switch line.

Identify the switch line, this IS NOT a live and Neutral as you state in your post, although I accept this could be a mistype. One will be RED, the other Black, but both are LIVE when the switch is operated.

Now, you have the switch line, choose which of the two you wish to be the feed to the switch, normally this is the RED, this shopuld be connected to the terminals with the other two red cores from the other cables.

The Black core, mark with red tape if you have some, this should connect to the BROWN cable from the actual light fitting, this is the return live from the switch.

The remaining two Black cores, and the blue core from the fitting should all be connected in a common terminal as these are the NEUTRALS.

Finally, connect all the Earth cores together.

Ensure all the terminals are tight, but do not overtighten either, and then turn the power back on.

All your lights will work.

 

[ban-all-sheds]

Oh all right then...

The only thing that puzzles me is that Kent wrote:

There are two mains leads coming into the fitting and one switch lead (3 in all).

Sounds good

All the earths have been wired together (as per instructions).

OK

All the earths have been wired together - loop (as per instructions).

Earths again, and the word "loop" ?? Would it be reasonable to assume that as there is no mention of Lives, that he meant to write "All the lives have been wired together - loop"? In which case also so far so good.

The two neutrals have been joined to the lamp cable neutral and the switch neutral has been joined to the live lamp cable.

Now - he says he's checked the fuse, and it's OK. If at this stage he had mixed up the switched live and one of the real neutrals then that fuse would have blown the instant he flicked the switch. But it hasn't so I don't see how he could have connected the switched live and a neutral. So given that there were 3 black wires, and he has got the correct two connected together along with the lamp neutral, and the remaining black (or switch neutral as he called it) has gone to the lamp live, why aren't the lights working? If he'd taken the incoming neutral to the lamp, and the switched live to the neutral block, then the fuse would not blow, because there would no longer be a neutral conductor where the switched live is, but that light, and the ones before it in the chain would work.

 

[Big_Spark]

I agree with your assessment of the situation, I was trying not to prejudge the post, simply assumed there were some typo's and terminology misunderstandings.

Personally I think he may have blown the fuse and not realised it has blown if a rewirable, which I think it may be as he specifically said fuse.

Hopefully he will post and let us know the situation.

Ban, one thing, I assume you host those pictures yourself, as such, do you think it would be a good idea to have one of them showing a Red and Black linked to the switched, with it simply identified as a LIVE in text and comment about marking it with Red tape or sleeving??

 

[ban-all-sheds]

Ban, one thing, I assume you host those pictures yourself, as such, do you think it would be a good idea to have one of them showing a Red and Black linked to the switched, with it simply identified as a LIVE in text and comment about marking it with Red tape or sleeving??

Never assume.

Nope - the pics are nothing to do with me - it's just a site I found and I thought the pic was a pretty good one. I agree that the cable to the switch could be better drawn - in future I'll add a little explanation to say that switched live is usually black*, and should be marked with red tape or sleeving. And that there should also be an earth running to it.

* is it? I know it is when I do it because I'm not going to go and buy a reel of red/red just for a few light switches, but what's common practice with professional electricians, do they tend to use normal cable, or red/red?

 

[Big_Spark]

is it? I know it is when I do it because I'm not going to go and buy a reel of red/red just for a few light switches, but what's common practice with professional electricians, do they tend to use normal cable, or red/red?

If using T&E then the normal is to use standard RED/BLACK and sleeve the black with RED sleeving. Some Specs for jobs will state RED/RED must be used and you occasionally come across it, but to be honest it isn't common.

When doing the lighting in Singles it is a different story as only the Neutrals are BLACK.

 

[dingbat]

If using T&E then the normal is to use standard RED/BLACK and sleeve the black with RED sleeving. Some Specs for jobs will state RED/RED must be used and you occasionally come across it, but to be honest it isn't common.

When doing the lighting in Singles it is a different story as only the Neutrals are BLACK.

I've taken to using Red/Red simply because it makes everything so clear and means you don't have to keep stooping down to pick up the bit of red sleeve that dropped off. (Hardly any significant difference in price after all.) As for using singles I just replaced the lighting circuits in a property that had originally been wired in concealed conduit (lovely for re-using the switch drops, but a pain everywhere else!) Anyhoo, when an extension was built some years back whoever did the wiring used a mixture of singles for the main circuit with T + E for the switches. Trouble was he only had red single and earth, which was used for both live and neutral. Quite a surprise to see a reverse of the usual situation - nearly all cores at a luminaire red, except one is neutral, with a single black... which is a switch live. Took me a few minutes to figure out. Still, eh?

 

[securespark]

Ladies and Gentlemen, KentGull has left the building...`

 

[Big_Spark]

Ladies and Gentlemen, KentGull has left the building...`

Well lets hope he hasn't joined Elvis and Lord Lucan!!

 

[securespark]

 

[KentGull]

No, not left the building, but sitting here feeling quite stupid. Originally I posted this on the 'General DiY' forum and hadn't realised it had been moved here. Just found it.

Yep, I got it wrong. It was all wired up correctly. My terminology for the wiring was as stated 'completely wrong'. It was the fuse all along. I checked it again today after being three weeks with no lighting upstairs apart from the odd lamp and hey presto! Lights.

In future I'll stick to woodwork and leave the electrics to those who know what they're doing! I'll get my coat