Dodgy light bulb adapter

[SimonH2]

I bought a couple of LED lamps (SES or E14 threads) to try out in some fittings. As it happened, they weren't aesthetically suitable so I bought a couple of adapters so I could try them in other locations.
One of the adapters (to E27 or ES) is fine. The other is ... to put it mildly, not fine.

The adapter in question is this BC to SES one. Anyone want to hazard a guess as to why I think it's dangerous ?

 

[PrenticeBoyofDerry]

Having never had to fit one, I hazard a guess that it is possible for centre contact not be connected to phase conductor but to screw thread.

 

[mfarrow]

I hazard a guess that it is possible for centre contact not be connected to phase conductor but to screw thread.

It looks quite well shielded though. Even if positioned "correctly" the screw is still technically a live part.

 

[JohnW2]

Having never had to fit one, I hazard a guess that it is possible for centre contact not be connected to phase conductor but to screw thread.

... which is, of course, inevitable with any bayonet to screw adapter. Having said that, the screw seems pretty deeply 'protected' within and insulating shroud in this case.

Kind Regards, John

 

[SimonH2]

Hmm, thinking along the right lines - but at the wrong end. One of the BC contacts is connected to the BC shell

Of course, in a plastic holder, this just means that there's a 50-50 chance of an exposed bit of metal being live. In a (properly earthed) brass lampholder it means a 50-50 chance of a dead short between L & E, and the other 50 is a short between N & E. Parents weren't amused when the TV went off Still, it looks like the discrimination between overload devices worked - the fuse in the plug blew, the RCD tripped, but the 32A MCB didn't trip.

So a question. OK I can report it to the vendor, but given that it's an electrical safety issue, should I also report it to Trading Standards so they can see if there's a trend (eg other people finding faulty ones) ?

 

[JohnW2]

One of the BC contacts is connected to the BC shell

Do you mean (seemingly) 'intentionally', or accidentally? I suspect that we've all seen BC lamps with an errant piece of wire or solder 'accidentally' joining one of the contacts to the BC shell.

Kind Regards, John

 

[SimonH2]

Looks OK, but on testing it's got a hard short - my MFT says 0.02 ohm. Looking down the socket, I can just see the wire from that contact to the outer screw terminal of the socket - but I can't see if it's intended to touch the shell or not.

Interestingly, I tried putting the torch to the "black" end of the BC plug, and found that it's glass and allows a lot of light through. That makes both connection wires visible. I'd need a tiny sliver of mirror to see if the short is deliberate or accidental.
The BC contacts are, like most light bulbs, just formed with solder.


And the socket is quite well shrouded - I'd not be worried about the SES screw cap being accessible.

 

[SimonH2]

OK, found time to get some pics. First off, the adapter and bulb - you can see the shroud fully covers the screw cap of the bulb so I've no worries there. As i said, I didn't buy the bulbs with the intention of using an adapter - I bought them to try in a specific luminaire but aesthetically they didn't "work". They are 7W Megaman dimmable BTW - seem pretty impressive for light output

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• SimonH2
• 29 Oct 2013
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• SimonH2
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These are the best photos I can manage of the adapters (the last one is sat on top of a small torch shining up through the glass insert of the cap), but it looks very much like they are identical except for the cap. That makes me think, what's the odds that if I remove the cap from the BC one, I'll find that the outer contact of the socket is (by design) connected to the shell of the cap ?

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• SimonH2
• 29 Oct 2013
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• SimonH2
• 29 Oct 2013
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The vendor says "meet European electrical regulations and have CE certification", but I wonder if this is just what the (presumably Chinese) manufacturer told them. I find it hard to imagine that connecting the cap and one terminal of a BC adapter could meet any sensible safety regs.

Time to drill out the little dimples and see what I find. Won't be able to try that for a day or two though.

 

[JohnW2]

These are the best photos I can manage of the adapters (the last one is sat on top of a small torch shining up through the glass insert of the cap), but it looks very much like they are identical except for the cap. That makes me think, what's the odds that if I remove the cap from the BC one, I'll find that the outer contact of the socket is (by design) connected to the shell of the cap ?

If that proves to be the case, it would almost certainly influence what I personally would feel inclined 'to do about it'.

Knowing that the occasional lamp/bulb (hence probably also adapter) always seems to have 'got through' the QC and testing with an 'accidental' connection between one of the contacts and the 'shell', I don't think I would get too excited if it seemed that I was simply seeing such a failure of manufacture/QC/testing. However, if it looked as if the connection was intentional, I would be very concerned, and probably would involve Trading Standards in the first instance - as you say, it's all-but-impossible to believe that any sensible safety regulations/Standards would accept such a seemingly crazy design.

Kind Regards, John

 

[ban-all-sheds]

It's also all-but-impossible to believe that any action could be taken against the seller/importer of the item if you take it upon yourself to start drilling into it and dismantling it.

If you want to report it you must leave it alone, and hand it over to the authorities intact, so that they can investigate it.

 

[JohnW2]

It's also all-but-impossible to believe that any action could be taken against the seller/importer of the item if you take it upon yourself to start drilling into it and dismantling it. If you want to report it you must leave it alone, and hand it over to the authorities intact, so that they can investigate it.

That's true, but if Simon discovers that it appears to be an intentional design 'feature', then he (or Trading Standards) would presumably be able to get plenty more which had exactly the same 'feature'. If I were him, I would probably do the same - because, as I said, (rightly or wrongly) I probably wouldn't want to spend much time pursuing the matter if I concluded that it was probably an 'accidental' manufacturing/QC problem.

Kind Regards, John

 

[SimonH2]

Also, if after taking it apart it is obvious that the short is by design, I can go to the authorities (Trading Standards) with a "this product is dangerous by design, and this is why" - rather than a vague "I bought this and this one is faulty".

Given the constraints on their budget (and hence time), I suspect the latter would result in nothing more than an exchange along the lines of :
"You sold X to someone, he claims it's dangerous"
"It must have been faulty, our products are certified to EU standards"
"OK then"

For the former, they've got a bit more reason to expend effort (= budget)

Biggest problem is that even if this seller drops them, there are probably dozens of other vendors (in the UK alone) selling the same items from the same manufacturers. Can you really imagine attempts to get the original manufacturers to hand over a list of who they are selling to/have sold to ?

 

[JohnW2]

Also, if after taking it apart it is obvious that the short is by design, I can go to the authorities (Trading Standards) with a "this product is dangerous by design, and this is why" - rather than a vague "I bought this and this one is faulty".

Indeed. I agree. As I wrote to BAS, I think I would do the same as you.

Kind Regards, John

 

[SimonH2]

OK, the autopsy report is in.

It's clear that the short isn't "intentional", but it is almost inevitable. My guess would be that if I open up the ES adapter, I'd find the side terminal extended to be trapped between insulator and cap, while on this BC adapter it's merely going to be touching. I'm fairly certain there was no gap at all, I've looked closely at the terminal and inside of the cap and see no evidence of an arc as would be present if it wasn't touching (I'm assuming I had a L-E fault as it blew the fuse in the plug).

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• SimonH2
• 31 Oct 2013
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So I'm inclined to think that this is something that's too serious to not take to Trading Standards - or does anyone think a different body would be more appropriate ?

1) It's almost guaranteed to have a short between one terminal and the cap. Even if there isn't a short, the clearance will be very small indeed.
2) There's a roughly 50-50 chance as to whether the cap will be connected to line or neutral.
3) Looking round out house, the majority of sockets (where they are plastic and hence won't just trip the MCB and/or RCD) do not shroud the bulb so as to make the cap untouchable.
4) This isn't just a "switch it off while changing a bulb" things - a lot of people use switches on table lamp holders and would be at risk of touching the exposed cap while feeling around for the switch.

 

[JohnW2]

OK, the autopsy report is in. ... So I'm inclined to think that this is something that's too serious to not take to Trading Standards - or does anyone think a different body would be more appropriate ?

As BAS said, I doubt that (given that it does not appear to be an 'intentional' design issue) Trading Standards (or probably anyone else) would be very interested/inclined/able to try to pursue it on the basis of your post-autopsy specimen. If I were you, and I felt inclined to take the matter further, I think I'd probably acquire a few more, in the hope that (non-destructive) testing will identify one more more further 'nasty' ones.

You could, of course, just try going to Trading Standards with your 'remants', but I don't think I'd hold my breath if you did.

Kind Regards, John