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Laws on electrical safety

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echase
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Post Number: 530
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Posted on Thursday, 18 August, 2011 - 11:34 am:   Edit Post Delete Post Print Post    Move Post (Moderator/Admin Only)

I question the legal framework we have in UK. If someone has designed something that involves mains electricity (I am thinking of something similar to the PIC controlled mains dimmer in EPE/Silicon Chip) they can get that design to other people in several ways:-

1. Put it in full on internet either as circuit diagram/source code or as a full constructional project with drawings/pictures.

2. Put the “low risk” (e.g. low voltage parts) on internet and only hint at the “dangerous” parts, e.g. with a text description only.

3. Get a DIY electronics magazine to publish it.

4. Make up finished units and sell them without having formal type approval, etc. done.

5. Make up finished units but leave all the mains side to the user to mount and wire up.

6. Get the product fully type approved and sell it.

No. 6 is clearly the safest way, but out of no. 4-5 and 1-2 which is safer? Anyone from an idiot to the best electrician/electronic engineer can take the design in no. 1 and 2 and try to make up a unit. As the design detail, especially in no. 2, is limited the end result could be completely unsafe and kill the person using the unit. But the designer is hoping that he is not blamable, especially in no. 2. But by failing to publish a good full design he is actually encouraging dangerous experimentation.

In no. 2 can it actually be said that the low voltage side is low risk? It could drive a high power mains relay in such a way as to cause a hazard, e.g. cause the relay to chatter.

No. 4 gives the public good quality units and takes away the risk that an idiot makes up the design in an unsafe way. Also feedback from early users helps to improve the product. So it improves the safety over no. 1 and no. 2.

No. 5 transfers some risk to the user but does not improve safety over no. 4 as some may make a hash of it.

I did no. 3 with my solar controller design that had mains relays in it. EPE said they checked the design (and made no changes) and that there is no real liability problem with this approach.

So in summary I contest that no. 2, which is widely practiced on the internet, is the least safe approach even though the designer is more protected from the law that under no. 4 or 5. This is not a fair application of law when the outcome is potentially more people being inured and not the intended less.

In another part of legislation it recognizes DIY electrical efforts in that initially it was proposed to ban all solder with lead in it, but I believe that an outcry from us DIYers left it such that it is now still OK in home built products.
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davejs
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Post Number: 29
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Posted on Thursday, 18 August, 2011 - 04:59 pm:   Edit Post Delete Post Print Post    Move Post (Moderator/Admin Only)

"No. 4 gives the public good quality units and takes away the risk that an idiot makes up the design in an unsafe way."

I would say that this may or may not be true; what if the designer / builder is not quite as competent as you are assuming?

In addition, surely the risks, both financial and legal, for designer / builder are huge if, say, someone is injured or even worse killed by the device - I don't think that liability insurance would cover non-approved items.

If you can't CE mark it then (in Europe) you can't sell it or if you really want to conform to the law use it yourself! (See the guide to the latest EMC directive for confirmation of this).

All a pain in the back-side as far as we are all concerned but that's the way it is and as far as I can see there is no way round it.
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joe
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Posted on Thursday, 18 August, 2011 - 05:34 pm:   Edit Post Delete Post Print Post    Move Post (Moderator/Admin Only)

I'm fairly sure that option 1 is also fine, as long as you put the normal "hi-voltage - danger of death" comments on. At the end of the day, if the person building the project from just a set of plans on the internet (and you shouldn't always trust what you find on the net) isn't qualified to do so, then thats not your fault.

If it was your fault, that would imply that any information thats not safe to be read by everybody (how to repair your car, make a smoke bomb, build a house), should not be freely available on the net in case the wrong person read it, and had a go, but this isn't the case.

If you were to sell your design or parts, then I expect that consumer protection laws (in the UK) kick in.

I wonder how many people lost body parts or were killed trying to repair their own cars/brakes whilst working from the Haynes repair manuals. I'm sure there was some clause in there about getting your repairs checked.

I also wonder how many people have been prosecuted for selling faulty/dangerous electric devices on eBay? You see some of the junk people are selling and only a few adverts have any sort of warning on.

As for the lead free solder, us DIYers are such a small group, just a bug stain on their radar of the authorities. I think it was aerospace / militry (and possibly the medical equipment industry) that kicked up a stink.

Regards,
Joe
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ecotec
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Posted on Thursday, 18 August, 2011 - 06:06 pm:   Edit Post Delete Post Print Post    Move Post (Moderator/Admin Only)

Echase,

Electrical safety is only one aspect of CE marking.

You cannot separate out the electrical safety from the other requirements such as EMC.......You could design a product that whilst not giving the user electrical shocks or fire hazards could foul up aircraft radio or the Lifeboat service.

You can if you wish 'self certify' and affix the CE mark but you must identify your company on the product/User Guide in such a way that Trading Standards can find you should a problem occur.

Ecotec
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terrym
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Posted on Friday, 19 August, 2011 - 02:33 am:   Edit Post Delete Post Print Post    Move Post (Moderator/Admin Only)

"I'm fairly sure that option 1 is also fine, as long as you put the normal "hi-voltage - danger of death" comments on."

Unfortunately, not quite. There was a case in the USA (where else?), where somebody sued a kit supplier (and won) even though that warning was on the packaging. The argument was that the kit supplier should have known that there would be people out there, without suitable experience, who would ignore the warning and build the kit.

So, based on that and the fact that it appears nobody in this world can take responsibility for their own actions, none of the actions are safe in the sense of protecting yourself from liability.
In the sense of protecting people from the device in a safety sense, again, none of the actions work, because you will always get that one idiot that will poke a metal object into a live piece of equipment.
Hence all this governmental regulation supossedly protecting idoits from themselves and creating major headaches for everybody else.

TM
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joe
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Posted on Friday, 19 August, 2011 - 07:10 am:   Edit Post Delete Post Print Post    Move Post (Moderator/Admin Only)

Terry,
but your USA case wasn't option 1 - Selling kits of parts with constructions detail is a world away from just finding some design notes on the net.

Which reminds me of the bloke that went after McDonalds because he dropped hot coffee on himself and got burnt - the cup never actually "said" the contents were hot... they do now apparently.

The question I want answering, is how many people have been prosecuted because somebody was hurt following the advice in an internet article (electronics related)... religion, suicide and other activites are out of scope of this.

Regards,
Joe
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echase
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Post Number: 533
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Posted on Friday, 19 August, 2011 - 11:58 am:   Edit Post Delete Post Print Post    Move Post (Moderator/Admin Only)

Hmm! So looking at the kit option only (no. 5) many kits from say Velleman use a plug pack supply or limit relay outputs to 30VDC to avoid any mains on the PCB, etc. But they also sell things like valve amplifiers that are pretty dangerous to the unwary. How do they comply with the law and what law applies as presumably there is no need to CE mark/type approve these. Or do they assemble one, type approve it and then use that as their defence? Plus good instructions with lots of warnings. UK only, I am ignoring US here.

It is so refreshing when I go to South Sudan to do repairs there. I have been asked to mend some oxygen concentrators in a hospital there in October. Oxygen and mains makes for an explosive combination and in UK I would not touch one. But in Sudan if the choice is between patients dying due to lack of oxygen and my mending it without the right UK qualifications then the choice is clear. But there are those who argue that the whole world should use the same standards and so the Sudanese should not suffer a lesser standard of repair than in UK. The end result of that philosophy is that the machines would continue to sit broken in the corner.
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joe
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Posted on Friday, 19 August, 2011 - 12:11 pm:   Edit Post Delete Post Print Post    Move Post (Moderator/Admin Only)

I'm not sure that you can CE a kit, after all, most of the problems I've seen with devices are the way they've been designed and assembled. The actual components are usually from quality suppliers.

Not wishing to throw petrol over option 5, but that may not be so safe either. I've seen battery powered equipment (especially with NiCads) go up in a lot of smoke. Remember a couple of years ago, those Sony Laptop batteries that were catching fire. There was no mains involved there.

I think once you start to "sell" things, your on dangerous ground. You only need somebody to burn themself with a soldering iron and it will be your fault.

What the human race needs, is a bit of bleach in the gene-pool if you ask me.

Joe
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terrym
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Posted on Saturday, 20 August, 2011 - 04:26 am:   Edit Post Delete Post Print Post    Move Post (Moderator/Admin Only)

Joe, sorry, crossed the various points up.

Didn't have my glasses on (that's my excuse and I'll stick with it).

Wonder if bleach will be strong enough?

TM

(Message edited by terrym on 20 August, 2011)
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echase
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Posted on Monday, 22 August, 2011 - 11:38 am:   Edit Post Delete Post Print Post    Move Post (Moderator/Admin Only)

Bit of an aside. I previously mentioned here that a former church member had riddled our 1000 year old church with plastic and metal boxes full of relays, timers, etc to control various things. All very ingenious but some of these are dangerous and I need to replace them/get them replaced. I think most were installed by himself. Yet we recently had an electrician do a full electrical inspection, which we need for insurance etc. purposes, and he passed it all. Indeed he recently installed one of these devices which was made by this man just before he died at a grand age.

What is the legal status of devices like this?
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joe
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Posted on Monday, 22 August, 2011 - 12:03 pm:   Edit Post Delete Post Print Post    Move Post (Moderator/Admin Only)

I asked the chap who does the PAT testing how he could pass equipment, when he clearly didn't know what the equipment did.

His response was that he had testing criteria for devices that plugged into a standard mains socket (he wasn't interested in our server equipment that connects to 16A/32A commando ports). Basically, he was happy if the mains plug and cable were undamaged, the fuse in the mains plug wasn't rated higher than the mains lead, and that the entire assembly passed the PAT test. The fact that it was all hooked to a time-machine or WMD didn't concern him. As long as it was an electrically safe WMD was his only concern.

I assume the same applies to your church. As long as the setup passes the criteria of his testing and "looks electriclaly sound" (no lose wires, uninsulated earth / mains wires etc), then they are happy... That is, untill the place goes up in smoke.
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echase
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Posted on Monday, 22 August, 2011 - 03:48 pm:   Edit Post Delete Post Print Post    Move Post (Moderator/Admin Only)

I was not around when the Electrician did the testing but I assume it was mostly visual testing rather than PAT / insulation type testing. One home built device I opened up looked beautiful outside (the man was a real craftsman) but inside it had earthed timeclock gearwheels rotating 1mm from a bare mains conductor. No external test or inspection is going to show this up.

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