Is there a electrician in the house?

[swee'pea99]

Taking as read that I should get someone in who knows what the hell they're doing and stop being a bloody idiot, I find myself proper baffled, and wondered if the CC posse might have thoughts on the matter.

To whit:

I took the light fitting down from the hall when we were having the place replastered, and now I've put it back it doesn't work. And - and here's the funny bit - nor does anything else.

I know how the light fitting connects - I put it up in the first place - but took the precaution of taking a photo before removing it:

When I'd finished everything else in the hall I just put it back as it had been, and switched on, and... nothing. Subsequent ponderings and fiddlings have brought me to what seems a very weird situation, which is that if I test the contacts the brown and blue wires would be using - the extreme outside ones - using an electrical screwdriver, the wee neon lights up orange for both. But if you connect the lamp fitting - or any other electrical device - to those contacts, it doesn't work. I've tested it using my desk lamp, which works perfectly. Nope.

How can this be? And what should I try next (apart from the obvious)?

It occurs to me it might be worth a mention that tho' the neon light does come on, without question, it's not exactly burning bright...mean anything?

Thanks for any feedback. Feel free to go for the obvious. Fill yer boots. Don't thank me, it's what I do.

 

[fossyant]

Have you connected the ring main properly. Those there will, or should be three separate circuits, but you should have wires going to the outer two connectors as well.

 

[si_c]

Taking as read that I should get someone in who knows what the hell they're doing and stop being a bloody idiot, I find myself proper baffled, and wondered if the CC posse might have thoughts on the matter.

To whit:

I took the light fitting down from the hall when we were having the place replastered, and now I've put it back it doesn't work. And - and here's the funny bit - nor does anything else.

I know how the light fitting connects - I put it up in the first place - but took the precaution of taking a photo before removing it:

View attachment 662069

When I'd finished everything else in the hall I just put it back as it had been, and switched on, and... nothing. Subsequent ponderings and fiddlings have brought me to what seems a very weird situation, which is that if I test the contacts the brown and blue wires would be using - the extreme outside ones - using an electrical screwdriver, the wee neon lights up orange for both. But if you connect the lamp fitting - or any other electrical device - to those contacts, it doesn't work. I've tested it using my desk lamp, which works perfectly. Nope.

How can this be? And what should I try next (apart from the obvious)?

It occurs to me it might be worth a mention that tho' the neon light does come on, without question, it's not exactly burning bright...mean anything?

Thanks for any feedback. Feel free to go for the obvious. Fill yer boots. Don't thank me, it's what I do.

Firstly, I'm not an electrician, but I have done a fair bit of DIY stuff with electrics. It's worth pointing out that you're using a voltage sensor which can detect flow if you have an open neutral, this is where you have lots of circuits with a common neutral running back to the board, this is likely to be the case with a lighting circuit.

My first thought is that you've not connected up the wiring properly, I'm assuming that it is a single light fitting with a single switch, so you might have two or three wires coming together at the pendant backplate plus the line out to the lamp itself.

If you have only two wires behind the lamp then you have just the switch and line in, if you have three then you have a ring setup where there is a feed to the next light in the ring as well.

Either way this picture should help undersand how the wiring should look. Click on it for a better explanation

 

[presta]

Unless the rose is the last one on the end of the circuit, it will have an output to the next rose:

 

[cyberknight]

assuming you wired it up right it could be when you put it all back up some wires have touched inside and you have shorted out your fuse /trip box

 

[swee'pea99]

Thanks very much!

My circuit looks like the one Presta posted - a bunch of wires in the middle, none of which I've ever touched - with the light fitting wires going into the outermost holes on each end.

Am I understanding this right - when you say

you're using a voltage sensor which can detect flow if you have an open neutral,

...does that mean that my dim-glowing electrical screwdriver might just be registering 'flow from my open neutral', which is why it won't power my desklamp? That although it 'looks live', there's not actually a working voltage/amperage/whatever at those contacts?

One thought that occurred to me while I was doing backstroke earlier...a few weeks ago I discovered the living room light wouldn't come on. At the time I just added it mentally to the list of Things I Have To Do (but no real urgency). But might there be a connection? Is this time to check the fusebox? (The 'Downstairs lighting' switch in the box seems fine - doesn't refuse to go on or anything.)

Thanks again for all posts, really appreciate the help.

 

[si_c]

Unless the rose is the last one on the end of the circuit, it will have an output to the next rose:

That looks right to me. And from what the OP posted seems to corroborate that. I have a slightly different setup on some (but not all) of the lights in my house, they are older pendant style lamps with no wiring plate in the base so the wiring is done in the ceiling using wiring blocks, it's ugly but functional and I could rewire them all but I'm not going to bother doing that until I replace all the light fittings.

Am I understanding this right - when you say

...does that mean that my dim-glowing electrical screwdriver might just be registering 'flow from my open neutral', which is why it won't power my desklamp? That although it 'looks live', there's not actually a working voltage/amperage/whatever at those contacts?

That's my understanding, yes. If you think about the wiring diagram above, all the neutral lines in a lighting circuit run together at some point (the consumer unit if not sooner), in simplistic terms the live wire carries the current to the light and the neutral carries it away, the reason it can do this is it should sit at 0V where the live wire sits at 220V. It's this difference between the two that allows the current to flow back to the power station.

In practice however the balancing that is done to let this happen may not be perfect, so you can get some potential voltage bleeding through in your home system if that is the case, it is always low as the voltage on the neutral should be 0V, but if the voltage is say 0.1V depending on the sensitivity of your voltage detector it may pick that up.

Edit to add: Regardless of how low the voltage on the neutral line it is always a bad idea to work on electrical systems live. Always turn the circuit off first and verify.

 

[Deleted member 26715]

Start with the usual, not a Sparky, but done all my own stuff for years,

Looking at your photo the 2 blacks on the left are your negative line circuit, I'll call them line as they are not a ring. The 3x reds, 2 again are your line & the 3rd goes down to your switch, the circuit comes back from the switch on the black with red tape on it, it has red tape on it because when the switch is closed that wire has live on it. Logically your bulb needs to go between the outside set of connectors black & black with red tape.

Things to check, do you have a good bulb? because it worked when you took it down doesn't mean it will now, has the switch plate been off, have you checked the wiring in the back of there? If you connected your bulb wires between the 3 reds & the 2 blacks is it constantly on? Do any of you other lights work?

 

[CXRAndy]

Don't use neon test lights. They give false live readings if neutral is floating. A proper digital multimeter is best. If you know how to use them

Brother in-law used a neon to fault find a faulty electric lawnmower. Having fitted new switch, brushes. He phoned me .

Two minutes later found fault broken neutral wire before switch

 

[swee'pea99]

Thanks again!

Things to check, do you have a good bulb? because it worked when you took it down doesn't mean it will now, has the switch plate been off, have you checked the wiring in the back of there? If you connected your bulb wires between the 3 reds & the 2 blacks is it constantly on? Do any of you other lights work?

The bulb's fine (and I've also checked with my desk lamp, which also works fine). Has the switch plate been off? Yes it has! I should have thought of that. The plasterers loosened it off. That's definitely one to check. "If you connected your bulb wires between the 3 reds & the 2 blacks is it constantly on?" No - it's constantly off. Nothing I've connected to that ceiling fitting seems to work, regardless of whether it's switched on or off.

Would I be right in thinking that since the switch stays happily in the 'on' position...

...this can't be a universal 'ground floor lights' issue, but must be localised to this one ceiling fitting? (With some problems in the past, the switch simply wouldn't stay 'on', but insisted on flipping back down until the problem had been dealt with.)

PS I've suddenly noticed, since posting this pic, the wee black bit in the middle of that - and only that - switch.

Does that mean anything? And if so, where should I start in looking for a solution?

Thanks again! Feel like I might be getting somewhere! Two steps forward, one step back...

 

[Deleted member 26715]

If you also say that the living room light does not come on, if the feed comes from the CU (consumer unit) to the living room, then to the hall the fault may not be in the hallway connections. Do any other lights on the ground floor work? If they do, do they stop working when you turn off that breaker?

 

[swee'pea99]

If you also say that the living room light does not come on, if the feed comes from the CU (consumer unit) to the living room, then to the hall the fault may not be in the hallway connections. Do any other lights on the ground floor work? If they do, do they stop working when you turn off that breaker?

The 'LIGHTS GROUND FLOOR' switch only connects to the hall light and the living room. The other ground floor lights are all on LIGHTS KITCHEN.

That black blip is calling out to me.....I just don't know what it's saying...

Once I've finished this coffee I'm going to take a look behind the switch in the hall - the one the plasterers removed.

Talk about a cliffhanger...

 

[Arrowfoot]

I had garage lightbulb that stopped working all of a sudden. So much time spent on DIY trouble shooting. Finally called sparky who recently passed his apprenticeship. Used to follow his boss on work assignments. Traced the fault to a an upstairs bulb fitting in one of the bedrooms in 10 minutes flat. Till today I have no clue what happened. And I will remain clueless.

 

[swee'pea99]

Disappointingly it all looks rather in order...

Hmmm.... <strokes beard thoughtfully emoji>

 

[Deleted member 26715]

Please think about what I'm putting BEFORE you attempt it & be VERY happy doing it BEFORE doing it.

Switch off the power at the main CU, remove the cover of the CU, then next to the fuse you are working on is a spare 6A one, WITH THE POWER OFF unscrew the live & swap it over to the spare then put the power on & see if your lights work.

If you're not happy to do this then a Sparky is you next logical step.