Christmas lights.. aargh near disaster

[blacksheep]

Thinking of fitting an RCD unit to the plug socket of the christmas lights next year (if I havent sorted my wire-fuse Consumer Unit to an RCD one)

My 2 year old daughter went behind the christmas tree, fascinated by the lights bless her, and put one of the bulbs in her mouth and completely bit through it !!

Now im not too sure on the xmas lights we have got, they goto a green box and there is 4 seperate circuits of lights from this, not sure what sort of voltages are over the bulbs but they are not outdoor ones. The green box doesnt feel heavy enough for a transformer although im aware there are other ways to drop the voltage.

What went through my mind is the other set we had are just a load of bulbs in series.. just think if it had been these and she had been closer to the live end being the further you go down the chain the voltage drops. Id imagine any where over the first half to 2/3s would at least give her a shock, wet mouth and all. No doubt earlier on in the chain would likely cause possible death.

Dunno wot to think about it all really but scared me

 

[ban-all-sheds]

I've never seen any tree lights with an earth, so an RCD would be useless as there would be no L-E or N-E path available to cause an imbalance. And even if there was if your daughter was in the L-N path the RCD would detect nothing wrong and would not trip.

Get some LED lights.

 

[THRIPSTER]

Happy New Year


You sure about that BAS? The RCD will detect any difference between phase and neutral currents. So if the baby bit through the bulb and happened to divert more than a nominal 25mA to earth the RCD would trip. If, however, the baby bit into the bulb and wasn't touching anything that provided an 'earth' then the baby would receive a 230vac belt across the tongue.

Regards

 

[NotHimAgain]

IMO this type of light is dangerous and should be withdrawn from sale.

It is no use relying on an RCD - even if it did detect a divert current to earth, you cannot guarantee it would be quick enough to save a toddler.

I recently carried out a periodic inspection at Leisure Centre - I found a cheap set of series connected 230 volt lights in the Creche - a member of staff thought the children would like them and decided to put them up.

I asked the manager about his company's policy on this sort of thing. I then asked him to consider the headline in the Sun 'Newspaper' if a child were to be killed - and I also asked him if he would expect to still be employed afterwards - he removed them.

 

[blacksheep]

Thats how I read that the RCD works, by detecting the difference between the L N phases. The earth path is to blow the fuse.

There will still be a path to earth through the baby! (for RCD)

Definately LEDs next year, but as the Consumer Unit is in the pipe to be done ive got even more reason to get that done first.
Hopefully with an RCD CU I should be ok but might as well put up LEDs anyway as a precaution.

Id suspect it would take a lot less to give a 2 yr old a lethal shock than us.
Doesnt bear thinking about!

 

[THRIPSTER]

Blacksheep,


There will only be current flow through the baby to earth if the baby is in contact with something that provides a path to earth. For example, if sitting on a nylon carpet, there is unlikely to be any path to earth and therefore the RCD will not trip.

In the instance cited, the immediate danger will be caused by burns to the baby's mouth.


Regards

 

[blacksheep]

IMO this type of light is dangerous and should be withdrawn from sale.

Totally agree. Why this wasnt thought about when they done safety checks for whether they are allowed to sell these. I assume they do check these things!

I recently carried out a periodic inspection at Leisure Centr

Crazy, so easily done though and I bet the member of staff didnt have any idea this could be dangerous. Probably been done elsewhere too.

@THRIPSTER

unlikely to be any path to earth and therefore the RCD will not trip

But if there is no current to earth there would be no big danger of getting a shock, other than say bridging the bulb filament. There maybe burns from the heat and glass too (she spit the glass out too me in my hand!).

It is my understanding that, although not necessarily a good earth connection, most places in a house provide good enough earth connection to cause severe shock / death. I bet the 25ma or whatever it is, is much reduced for a babys heart (or even a shock to other vital organs like the brain?)

 

[ban-all-sheds]

IMO this type of light is dangerous and should be withdrawn from sale.

Totally agree. Why this wasnt thought about when they done safety checks for whether they are allowed to sell these. I assume they do check these things!

What kind of safety precautions could be taken to prevent someone biting through a very small and thin glass envelope?

Do you have any reason to believe that you bought lights which were not CE marked, and therefore did not comply with the appropriate standards?

I recently carried out a periodic inspection at Leisure Centr

Crazy, so easily done though and I bet the member of staff didnt have any idea this could be dangerous. Probably been done elsewhere too.

Yup - definitely done elsewhere. And last year. And the year before that. And the year before that. In fact, it'll have been done for years and years and years and years.

Why?

Because for years and years and years and years tree lights have been series connected - e.g. 80 in a set and they'll be 3V lamps. That's where we get the cliched image of not being able to get any of the lights working because one has come loose, or, if they are the type of lamp which doesn't fail closed, because one has blown.

It's only relatively recently that LEDs have allowed ELV lighting - there's no way that you could have hundreds of individual ELV incandescent lamps in parallel, as the cable would need to be too thick.

It is my understanding that, although not necessarily a good earth connection, most places in a house provide good enough earth connection to cause severe shock / death.

No - most places don't.

Use Ohm's Law to work out what minimum resistance you need to allow at least 30mA to flow, and then think what the resistance of a wooden floor, or carpeted floor, or one covered in some kind of plastic would be. Or of a dry papered and/or painted wall.

 

[NotHimAgain]

It's only relatively recently that LEDs have allowed ELV lighting - there's no way that you could have hundreds of individual ELV incandescent lamps in parallel, as the cable would need to be too thick.

Many incandescent lamps are 0.7 watt, 3 to 6 volt - I don't see that as technically challenging - I can use a supply voltage up to 50 Volts from a SELV source. If I use 3 volt lamps I can have 16 in a series run if I want, that is just over 11 watt per run.

If I want 200 lamps on a system a 140 watt transformer will do it - where is the problem.

It just comes down to cost - ELV systems have been available for years - LEDs just make it cheaper.

 

[ban-all-sheds]

If I want 200 lamps on a system a 140 watt transformer will do it - where is the problem.

The problem is that 200 lamps will mean a cable length of at least 200' - so what size will it need to be to ensure that there is no noticable difference in brightness between all of the lamps on it?

 

[mattylad]

Hopefully next year she will be a year older & more able to understand when mummy & daddy tell her not to eat the Christmas tree lights

 

[NotHimAgain]

The problem is that 200 lamps will mean a cable length of at least 200' - so what size will it need to be to ensure that there is no noticable difference in brightness between all of the lamps on it?

Not if I do it in 16 lamp runs. You have been able to get them for years, but they cost more.

LEDS are much better as they don't produce as much heat.

 

[blacksheep]

Hopefully next year she will be a year older & more able to understand when mummy & daddy tell her not to eat the Christmas tree lights

Yeh hopefully! Although im not sure id want to chance it, just couldnt beleive how easy it was.

What kind of safety precautions could be taken to prevent someone biting through a very small and thin glass envelope?

Do you have any reason to believe that you bought lights which were not CE marked, and therefore did not comply with the appropriate standards?

Yeh granted it is hard to prevent this but it really amazes me that they have allowed lights like this to be put on sale in the first place. Why not low voltage transformers or similar. You could at least group together say 10 at a time so its safe. In fact I have another set that do patterns and this requires groups to made up showing there is not problem in doing so. Same with LEDs, you could do group of 30/40/50v or something, at least it would be safe!

Seems like a no-brainer to me, safety should always be first not cost!

Funny - about 10 mins ago I had someone standing by me talking with a set of the in series types in her hand!!

 

[mattylad]

I have a tree bought from Asda that has LED lights on it, they use a step down transformer/adapter.

 

[sm1thson]

Extra low voltage ones all the way for me, my current ones arent LED but still extra low voltage. LED ones have dropped loads in price. you still need to pay more for the better ones, if you dont like the 'ice white' (bluey white) look of most LED ones, go for 'warm white LED' ones there seemed to be a lot more of them on sale this year and they give a more golden colour like 'normal' bulbs, when i replace mine thats what i will be getting.