No power through ceiling rose

[smartin1612]

Hello all,

I'm replacing a 3-bulb spotlight with a standard BG ceiling rose but upon connecting, the light won't turn on; the problem is, I can't see why.
We can handle the wiring shortly, but after a day or two of testing - wiring the spot back on, test (it works), replacing with the ceiling rose (it doesn't work), I finally gave up and wired the spotlight to a plug and tested - dropping the 13A down to a 3A first.
The spotlight predictably worked as expected, but upon switching over to the ceiling rose, using the same bulb as the spotlight - it's a 7w bulb, I'm not getting anything, although I am registring power both on the cable terminals and, the light terminals, just no light. It's as though the light terminals are performing a huge resistence that the power could not overcome it and light the lamp.

I have already gone through the motions of junction boxes and switches trying to troubleshoot, which came-up blank - even to wiring the rose direct to the light cicuit and the junction box in the attic [we're still on junction boxes for the lighting circuits rather than using the rose loop] to bypass the switch [using the RCD as a switch], and predictably, I got nothing, hence the direct to wall-outlet approach as a last resort.

Any ideas?

 

[smartin1612]

I wasn't being rude btw i was trying to make the point that had you used a multimeter you wouldn't have had to wait 7 days and could have found where the fault was in a few minutes.
The item you are using for doing testing is unsuitable to say the least.

The reason for needing to wait 7 days was one of available light: I'm not about to start messing with mains electricity in the dark using only a torch, this includes using a multimeter.
I began this work last Sunday afternoon (11-12), couldn't resolve before it got dark, and then due to the dark winter days had to wait until this Saturday to look into. Had I been working in BST May-August, I'd have been able to resolve in a heartbeat.

And again, just becuase I didn't explicitly explain that I was using a multimeter, this does not mean I am not. A multimeter is an ESSENTIAL piece of electrical kit - cripes this is drilled-in from the age of 11 in both physics and design/technology classes. If you're not a strong swimmer, don't go near the water. If you plan on doing electrical work, don't begin without a multimeter simple as.
So in this instance, rather than assume that I'm not using a multimeter, the better method would have been to determine whether I was using a multimeter properly, by asking whether I had tested continuity through the lampholder. I would have been less annoyed at this question as it displays a desire to engage and educate, rather than to assume I am playing with mains electric using nothing more than tin-foil lined gloves!

It was only after I had successfully tested continuity, that I had determined the problem to be related somehow to the lampholder, I just could not work out what, which therefore meant isolating from mains, and testing the lampholder individually.
A lampholder is just a simple circuit, and a general ceiling pendant is no different from a table lamp, so I cannot see how my wiring a 3A plug on and powering from a pure-sine power-pack to test to identify the cause is 'unsuitable'.

 

[smartin1612]

Baffling how something so simple could turn into a Commons Debate.
Get a spark in for 5 minutes.

To what point and purpose? I wouldn't learn anything. As it happens, I did learn. I knew the problem was related to the lampholder in some way, and I now know as does everyone on this post, and any other reader of this post, that in such a situation, try adjusting the terminals first.
Had I paid for a spark, they'd have diagnosed the cause in minutes, but this thread would not have existed, as I would not have felt compelled to document my experience somewhere, so others would similarly be in the dark too, as the B&Q customer feedback section demonstrates

 

[smartin1612]

At a guess, the neutral contact for the lamp was contacting the insulating section on the bottom of the lamp, and was being bent inwards, towards the live contact and centre terminal of the lamp, as it was screwed in, instead of sliding up the side of the lamp base onto the threaded section.
Unscrewing it a little brings the neutral contact just into contact with the lower edge of the threads.

Yes, this is it, thank-you @brianmoooore, this is precisely what I expect is happening, and why I could not explain how moving the terminal further away from the bulb resolved the problem

"and was being bent inwards, towards the live contact and centre terminal of the lamp, as it was screwed in, instead of sliding up"
Maybe I'm just not clear in explaining it, and being inside a lamp holder, I'm also unable to see what was happening, but this explanation I believe is exactly what I'm trying to tell the rest of this thread.

Thank-you.
Steve

 

[smartin1612]

It doesn't appear that a short has taken place I suspect the problem to be poor quality of the component. Modern ES holders are not polarity biased, just for info.
Which lamp holder is giving the problem the left or right.

Difficult to say really - both and neither, that's not my photo but the one by another B&Q customer on the products' feedback page

 

[mainline]

The reason for needing to wait 7 days was one of available light: I'm not about to start messing with mains electricity in the dark using only a torch, this includes using a multimeter.
I began this work last Sunday afternoon (11-12), couldn't resolve before it got dark, and then due to the dark winter days had to wait until this Saturday to look into. Had I been working in BST May-August, I'd have been able to resolve in a heartbeat.

And again, just becuase I didn't explicitly explain that I was using a multimeter, this does not mean I am not. A multimeter is an ESSENTIAL piece of electrical kit - cripes this is drilled-in from the age of 11 in both physics and design/technology classes. If you're not a strong swimmer, don't go near the water. If you plan on doing electrical work, don't begin without a multimeter simple as.
So in this instance, rather than assume that I'm not using a multimeter, the better method would have been to determine whether I was using a multimeter properly, by asking whether I had tested continuity through the lampholder. I would have been less annoyed at this question as it displays a desire to engage and educate, rather than to assume I am playing with mains electric using nothing more than tin-foil lined gloves!

It was only after I had successfully tested continuity, that I had determined the problem to be related somehow to the lampholder, I just could not work out what, which therefore meant isolating from mains, and testing the lampholder individually.
A lampholder is just a simple circuit, and a general ceiling pendant is no different from a table lamp, so I cannot see how my wiring a 3A plug on and powering from a pure-sine power-pack to test to identify the cause is 'unsuitable'.

You said that you had spent days troubleshooting this problem.

If you had used a meter properly to check for continuity in the first instance, you wouldn't have had to go through the motions of wiring plugs leads etc.

The only mention in your posts of a multi meter was in not feeling the need to use one, but you did show a pic of your totally unsuitable £1 voltage checker, which was the item I was referring to.

 

[nicebutdim]

To what point and purpose? I wouldn't learn anything. As it happens, I did learn. I knew the problem was related to the lampholder in some way, and I now know as does everyone on this post, and any other reader of this post, that in such a situation, try adjusting the terminals first.
Had I paid for a spark, they'd have diagnosed the cause in minutes, but this thread would not have existed, as I would not have felt compelled to document my experience somewhere, so others would similarly be in the dark too, as the B&Q customer feedback section demonstrates

Probably the greatest lesson to learn is about buying cheap electrical products from DIY outlets. In this instance it was a simple enough fix, but a lot of light fixtures sold in the UK are of terrible design - mainly a nightmare for compliant installation, but often also stretching the defininitions provided in applicable British Standards.

Two things that amaze me in this life are flimsy insulation provided as protection against electric shock and cheap fibre washers that we depend on to not have flooded homes.

 

[smartin1612]

You said that you had spent days troubleshooting this problem.

If you had used a meter properly to check for continuity in the first instance, you wouldn't have had to go through the motions of wiring plugs leads etc.

The only mention in your posts of a multi meter was in not feeling the need to use one, but you did show a pic of your totally unsuitable £1 voltage checker, which was the item I was referring to.

You really need to learn to read between the lines, and not
Just accept that you jumped to conclusions based on this being posted to the DIY borad. You assumed that because I hadn't explicitly made reference to various steps or using a multimeter, and I included my voltmeter in shot as I had just checked for voltage - it being easier with the flat-head screwdriver at that moment in time rather than traipse back upstairs to grab my multimeter, you've decided novice.
And, as a week had passed between my starting and cocluding, you have assumed that this was down to DIY incompetence rather than accept my explanation of lack of light and not wanting to work on electrics in the dark.

Through troubleshooting, I've managed to identify the root-cause as a poor terminal design and not, my initial thoughts as a problem with the rose.

Probably the greatest lesson to learn is about buying cheap electrical products from DIY outlets. In this instance it was a simple enough fix, but a lot of light fixtures sold in the UK are of terrible design - mainly a nightmare for compliant installation, but often also stretching the defininitions provided in applicable British Standards.

Two things that amaze me in this life are flimsy insulation provided as protection against electric shock and cheap fibre washers that we depend on to not have flooded homes.

Its actually really frustrating though, this was supposed to have been a quick replacement, as I said earlier, properly jarring when nothing worked.
We've lived in this house for 10 years - as tenants, purchasing from the landlord at the start of November, so we're in the process of making loads of changes which includes building our [long-awaited] extension, moving and fitting new radiators, extending the ring in several rooms, and switching terrible light fittings over.
But its fixed now, lesson-learned - start-off small and work up: so much more easier to adjust terminals away as well as toward (I only moved toward thinking the terminal wasn't making contact, and then suspected something else).
Its just a shame I placed too much faith in the lampholder. Oh well.

B&Q does make some good quality items, and many of their materials are cheaper but of the same quality as Wickes and TP, so it can be a bit hit and miss in determining between that which is good and that which isn't.

 

[nicebutdim]

B&Q does make some good quality items, and many of their materials are cheaper but of the same quality as Wickes and TP, so it can be a bit hit and miss in determining between that which is good and that which isn't.

In fairness, there's also plenty of junk available from electrical wholesalers

 

[mainline]

I included my voltmeter in shot as I had just checked for voltage

That thing is not a reliable or accurate means of testing and is better off in the bin.

 

[smartin1612]

In fairness, there's also plenty of junk available from electrical wholesalers

Oh don't get me started, I swear there's been an increase in junk these last few years, and we can lay most of it squarely at the feet of Amazon.
In order to keep-up, the large retailers buy the same junk and re-package it hoping that most will never find the time to return their rubbish. I live in a small village and am permanently home-based which generally means 8-6 (if I'm lucky), so B&Q is so much more closer for me than anything.

But electrical products aren't the only items to be crap, there's plenty of crazy expensive terrible IT equipment masquerading as high-quality too; wireless networks are the worst for it.
So really, whats a £4 ceiling pendant or light switch compared with a £150 router, just to find that false advertising has indicated two devices from the same line, from the same manufacturer, are not capable of forming a mesh system, as the indicated mesh system exists purely in the head of the person who drafted the advert.
I prefer databases and data engineering, these are incapable of lying about their abilities.

 

[mainline]

You find in all walks of life the type of people who believe they are competent, but actually know less than some novices.

 

[smartin1612]

You find in all walks of life the type of people who believe they are competent, but actually know less than some novices.

But as long as they're willing to learn, thats all that matters.
Its always a difficult moment having to fire someone who is unwilling to improve their skills despite multiple opportunities and support; from my perspective as the team manager, sometimes it can really hurt, as though I've somehow let them down.

 

[suffolkspark]

Looks as simple as that neutral being bent too far in so instead of sliding up the side of the thread, it stopped the lamp screwing all the way in so it didnt contact the line pin. Pretty common.

 

[MJPD29]

The wiring in those photos is horrendous. A little knowledge is a dangerous thing.

 

[smartin1612]

Looks as simple as that neutral being bent too far in so instead of sliding up the side of the thread, it stopped the lamp screwing all the way in so it didnt contact the line pin. Pretty common.

Oh, that's an interesting way of looking at it, I didn't think of that