Imported electronic downlighters and ongoing safety responsibility?

davebullockmbe said:

However, in my testing to find the fault I carried out some 'load' testing and found that in certain overload conditions the switching FET became extremely hot and looked like it would lead to the destruction of the driver and possible fire?

You are referring to your opinion of a hypothetical risk - so no one "official" is going to be very interested.

If you think it's important then at least give the importer/distributor the chance to the the decent thing and tell them about it.

Trading Standards https://www.citizensadvice.org.uk/consumer/get-more-help/report-to-trading-standards/ are responsible for enforcing CE marking regulations for consumer products in the UK and may have some advice for this situation.

The importer may belong to a trade organisation which might possibly take it up.

Generally situations like this do not provoke any official reaction (like publicity or recalls etc) until an actual (and serious) incident occurs. Mere failure out of warranty is not enough.

If you feel really concerned about then go public - name names and post some pictures - if you stick to facts it is perfectly legal to do so.

But you really should contact the distributor first and see what they say.

MK

davebullockmbe said:

However, in my testing to find the fault I carried out some 'load' testing and found that in certain overload conditions the switching FET became extremely hot and looked like it would lead to the destruction of the driver and possible fire?

You are referring to your opinion of a hypothetical risk - so no one "official" is going to be very interested.

If you think it's important then at least give the importer/distributor the chance to the the decent thing and tell them about it.

Trading Standards https://www.citizensadvice.org.uk/consumer/get-more-help/report-to-trading-standards/ are responsible for enforcing CE marking regulations for consumer products in the UK and may have some advice for this situation.

The importer may belong to a trade organisation which might possibly take it up.

Generally situations like this do not provoke any official reaction (like publicity or recalls etc) until an actual (and serious) incident occurs. Mere failure out of warranty is not enough.

If you feel really concerned about then go public - name names and post some pictures - if you stick to facts it is perfectly legal to do so.

But you really should contact the distributor first and see what they say.

MK

HI,

Thanks for all your comments and advice.

I was expecting that as Michaelkellet suggests that because (as far as we know) there is only a 'hypothetical risk' then no one would be interested.

I have discovered that the obsoleting of the driver module has occurred because the manufacturer has revamped the design using a different driver controller IC which doesn't exhibit this potential dangerous overload situation. (I've subjected one to the same barrage of tests) The driver unit is supplied in the same casing as the original and is externally indistinguishable from the earlier model other than a modification to the part number.
Of course one can hypothesize that this upgrade is a result of devastating failures or just the unavailability or the original driver IC. 
Hopefully the former but we will never know or possibly find out.

Of course my worries may be totally unfounded. Do COB LEDs ever go low impedance (which could cause this overheating situation), or do they ALWAYS go either short, or open circuit?
Was the item ever required to be tested under ALL load conditions? That's what I need to find out.

Lighting experts please comment.

Finally
I have scripted a long report of all my findings to the UK lighting seller, asking these questions (as some of you suggest), I am waiting for their response.
As they already informed me that the item is now obsolete I suspect they may be non-cooperative and hope that I just go away?

Having worked in a medical electronics environment it was imperative that understood potential electrical risks to patients and test subjects.
However dealing with domestic equipment and navigating the latest regulations (especially since Brexit) seems to be a minefield.
I don't have the time to do this hence my turning to the Element 14 community for your thoughts and advice.

It was never my intention to contemplate any legal challenge over my discovery but now the "Genie is out of the bottle" I am left in a moral dilemma.
Do I just return the repaired driver modules to my client as if nothing happened, or, do I mention my findings frightening him for the safety of his young family?
The UK supplier doesn't seem to have what I would call a 'technical' department that can understand their product to 'board level' so I wouldn't be surprised if they had just taken the Chinese manufacturers word that the item was safe.
I have opened a 'Pandoras Box' and don't like what I see........

Thanks once again for your thoughts, please keep them coming

Dave

For what it's worth I think you should be open with your immediate client and share with him any information you might have. It's sometimes hard to give clients the bad news but much easier in the long run to live with yourself if you do.

I don't know enough about LED failure modes to comment re low Z failure modes.

MK

This is not a unique situation from the point of view that millions of homes have dodgy electrical products ranging from genuine products like Whirlpool appliances to fake Apple chargers etc. It's a surprise when consumer products are of high quality (and they still may have some flaws).

Also, it might seem obvious to some that a heated FET condition may cause a dangerous fire, but this might not be the case, and it doesn't imply that standards were not met.

There was a case where there was an oil leak from a ship, and sparks caused a fire. The company causing the oil leak was not responsible, because even though the average person (and even some engineers!) might believe that an oil leak could cause a fire, in actual fact it was not reasonable to expect a fire to occur at all. It's easy to leap to conclusions.

If you think something is dangerous, you have to make your client aware of it, anything else is immoral. If it costs the client money to fix, so be it. I routinely swap out chargers for family members, because I don't trust what they purchase (obviously I don't charge them for that of course).

HI everyone,

First of all a great big thank you for all your knowledgeable responses.
Having taken your sagely advice I communicated my findings to my client who was somewhat concerned and subsequently gave me permission to carry out a "destructive" test on his LED driver.
Bearing in mind that when I discovered the issue the power FET became unbearably hot within 20 -30 seconds I had not ventured any further.
So I set up the test again but this time with a thermocouple bead thermometer fixed to the surface of the FET and then commenced the test.

Result
The FET rapidly gained in temperature as before and then more slowly until it reached a stable temperature of 78 Degrees C.
Relieved, I repeated the test with a slab of expanded polystyrene fixed over the surface of the entire pcb to 'more than' emulate the board being inside it's plastic housing.
Running the test again I monitored the FET temperature and it only increased to 85 degrees C, so I assume the pcb and associated trackwork was serving as an efficient heatsink.

So, I thank you all for directing me to persevere with my testing as it would seem I was becoming over cautious.

Dave