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View Full Version : Mains boxes are dangerous!



sparkymark567
-9th July 2003, 00:17
It canít be right that you wrap yourself in tin foil (a lame jacket) hold on to a piece of metal (a weapon) and then connect both of these to a scoring apparatus powered by the mains.

Many times I have experienced small electric shocks through the handle of my foil (and my handles do have an insulation covering). In my experience the worst offending boxes are the Leon Paul bug eyed boxes. I would like to suggest that any club who is still using a bug eyed box should take advantage of the Leon Paul swap deal. But then itís not just the bug eyed boxes, I have also experienced shocks from other Leon Paul boxes. At this point I should, add that itís not only Leon Paul boxes that have caused me a problem. The Faveo boxes, powered by an external power pack (through a DC jack plug) have also given me small shocks. Iím sure that I can not be alone in raising this concern (although I do tend to sweat lots when Iím fencing).

The SEMI committee states that F.I.E boxes should be powered by a 12 volt battery and Leon Paul do comply with this at competitions.

I consider it absolutely ridiculous for any manufacturer of fencing equipment, to ignore the recommendations of the SEMI committee and continue to sell mains powered boxes.

A commercial product such as a television, video player etc would undergo far more test procedures, than a fencing box, to ensure that it is safe. In many companies electrical equipment used by employees then undergoes further periodic testing e.g. once a year, to ensure that it remains safe to use. A fencing scoring apparatus is not usually tested in this way, but then time and time again we all happily connect ourselves to a mains powered box.

I would recommend that Leon Paul seriously consider the implications of their products with respect to health and safety. (Note that I do not particularly have a vendetta against Leon Paul as I blame other companies too.) I would suggest that Leon Paul offer and recommend a free safety test for all of their mains powered boxes. In fact, Iíd like to see them stop selling them altogether. Please!

Oh, and I thought I should just mention that I do know what Iím talking about as I have studied some electronics at university.

Iíve heard, that in the past (not sure of the exact details) that a fencer was electrocuted and died? as a result of walking in bare feet on a metallic piste, connected to a faulty box. Perhaps someone out there could confirm this.

Please think twice, before you next buy or plug yourself in to a mains box. Some manufactures are being very silly, they gambling with public safety and could find themselves on the receiving end of a very expensive legal case. It doesnít take much to kill someone when electricity is involved!

Barry Paul
-10th July 2003, 12:09
Leon Paul as required by law do a continuous risk assessment of all our product.
With regard to the shocks you report these are low voltage /capacitance discharge which is most noticeable on the Bug Eyed Boxes which use telephone relays, but as you correctly say occur on most old boxes and some new boxes.
As you also point out because you sweat so much you are more likely to feel these discharges, they are totally harmless.
With regard to the fatality you mentioned this had nothing to do with the recording apparatus. Unfortunately a mains power lead was placed under the metallic piste sheets ( this was a permanent installation) Due to wear between the cable and the metallic piste the piste became live. When a fencer after fencing sat down on the piste he lent onto a metal radiator. The resulting shock was unfortunately fatal.

due partly to the concerns as above, originally the F.I.E. passed a regulation that there should be no mains power in the fencing hall. However like many edicts from the F.I.E. this was not thought out, nobody did the calculation of the 12 volt DC voltage drop over the size of a large fencing hall. The resulting size of the external output transformers required would have been totally impractable. The F.I.E. subsequently stated that the an F.I.E. competition appartus and extention lights should be driven by 12 volts D.C. battery, but this was at least in part to prevent cheating by tampering with the incoming mains electrical supply. Apart from the U.k. most other countries ignore this requirement and have mains driven apparatus and extention lights for all their competitions.

Clearly like any electrical mains electrical device if any problems develop in use they should be inspected by a qualified person and or retuned to the manufacturer for repair.

haggis
-10th July 2003, 19:45
Originally posted by sparkymark567

Oh, and I thought I should just mention that I do know what Iím talking about as I have studied some electronics at university.


Although clearly not as much as Barry

sparkymark567
-11th July 2003, 12:16
Barry

I never suggested that the small shocks were of any great danger. Just that the design can't be very good! as it's not really what you expect. Also if it's due to capacitance why does it not happen on a battery box? On the LP microprocessor apparatus: you get shocks when they are plugged in to the mains, but never when they are plugged in to a battery!!!!

I think it's more to do with power spikes on the mains supply?
Why don't you fit transient voltage suppressors?

What happens if you have a pace maker. Maybe you should put a notice on the box so people know not to use it if they have one.


Barry? under what form does the continuous risk assessment take place? Where have you got the figures from, i.e. what's your probability of a fatality?
How did you work this out?
and what value in £££ do you put on a life?
What level of risk do you think is acceptable?

How can you be sure these figures are of the correct order? Have you taken any advice from the HSE or is it more of a paper exercise that you complete just because it's required so by law.

Suppose someone spills a drink? That Ďs a foreseeable risk with quite a high probability.

What safety protection systems are fitted inside you apparatus, (other than a fuse which wonít help very much!)

Next point is that most clubs do not have a qualified electrician to carry out a safety test. Why can't LP offer this?




Haggis

That is exactly your problem, you accept what LP says with-out asking them for proof. You accept what they tell you and put yourself at unnecessary risk. Anyway, what do you know about electronics?? as it seems youíre quite sure that Barry is correct!

Also, it's funny how you are King Kenny's pall. You seem to have some connection with Leon Paul?

sparkymark567
-11th July 2003, 12:40
And last night at my club in Bath, someone else complains that they are getting shocks from one of your mains powered microprocessor apparatus.

Please take my advice and buy battery powered box!

The LP boxes have a good battery life as they use high capacity lantern batteries.
You can buy the batteries for about £3 each if you go to B&Q.
There is really no need to use a mains box!!!! Better safe than sorry.

hokers
-11th July 2003, 14:35
Dude

You've got issues...

Has anyone ever had a serious mains shock from a fencing box?
Or ever had a cardiac problem related to pacemakers and fencing boxes?
Does anyone else know someone who has?

Sounds like a storm in a teacup to me.
Are you writing to manufacturers of vacuum cleaners and other household appliances to insist that they produce battery versions?
I get static shocks from my wife's car, but they're hardly cause to demand a public enquiry..

Anyway, there's loads of other manufacturers who make mains powered boxes, they can't all be designing them badly can they?

You're almost verging on libel here, so you might want to take this offline perhaps.

And before you ask, no I do not work for Leon Paul..

hokers

ceprab
-11th July 2003, 15:28
If you are getting shocks from touching many things then perhaps it is you that is electrically unsafe....?;)

Dave Hillier
-11th July 2003, 15:57
It sounds more like a static build up to me.

neevel
-11th July 2003, 18:10
I do get shocks from my little Favero LED tester, which uses a 12 V camera battery, when I'm checking weights while wearing a sweaty uniform and lame.

Shocks from old relay boxes of 4 decades ago were par for the course. Keep in mind that such shocks, just like static shocks, are being carried along the surface of your skin, not through the core of your body, and so aren't going to do any damage. The vast, vast majority of non-A-grade competitions around the world use mains powered boxes (nowadays typically drawing their power from off-the-shelf DC power supplies with UL or CE ratings). As Barry has mentioned, the oft-discussed electrocution incident had nothing to do with the scoring apparatus. With that excluded, how many instances of injury from the millions of bouts around the world that have been fenced with mains powered boxes for the last 50 years have you heard of?

The FIE's retention of the battery-power requirement is largely related to ensuring that bouts won't be affected by power outages (especially at tournaments held in countries where the power grid is less than reliable) or someone tripping over an extension cord.

-Dave (I've done post-graduate work in EE, btw)

Flaxen_Renegade
-12th July 2003, 08:59
I like to think I know some of the most dangerous Fencers around (possibly to help my Ego when I'm constantly thrashed :tongue: ) but they've never been shocked (to my knowledge), and neither have I. I don't see it to be at all risky; I regularly discharge from synthetic materials but I don't worry about serious injury (and I tell you sometimes that REALLY hurts!). I've had plenty of friends shock themselves by shoving their fingers INSIDE electronic equipment and they're all fine. You should only really worry if you have a Heart murmur and even then I wouldn't let it discourage me. I worry more about the dent in the front of my mask-now THAT could be fatal!

sparkymark567
-13th July 2003, 09:22
Quote Hokers

"Anyway, there's loads of other manufacturers who make mains powered boxes, they can't all be designing them badly can they?"

You're quite right, I've never had a shock from an Uhlman box.
So at least they seem to be o.k. I don't mind fencing on these, as they don't make me drop my weapon in the middle of fight. They seem to be quite well made.

sparkymark567
-13th July 2003, 09:54
I stand corrected with regards to the fatality. As I said I wasn't sure of the exact details. To the best of my knowledge there has not been a serious incident involving a faulty scoring apparatus.
However, I still regularly get shocks from LP mains boxes. I avoid using them as far as possible.

I'm not sure about the new boxes which LP now sell, I think these have a DC jack plug, so they might be O.K. It probably depends on the type of power supply unit being used. Those with a regulated output are probably the best type to use.

I do not buy the argument that the shocks could be due to static build up. As I said, the Ulhman boxes seem to be O.K. Also the shocks sometimes last for a couple of seconds

There was an earlier post on this forum, that one club who used a bug eyed box found that it dimmed the lights when they switched it on. This sounds very dangerous.

Would advise people to be weary of mains boxes, particularly if there is any possibility of a fault.

And no I won't be writing to the manufacurers of vacuum cleaners as you don't usually plug your lame jacket in to these. And neither is current supplied to a metal handle.

Shocks from an LED tester, I accept this is true, but then we know that they can't do any harm because they are powered by a battery. i.e. the best assurance.

Barry Paul
-14th July 2003, 15:16
Only joking.

The dimmed lights were also a joke.

For you information we made about 1800 bug eyed boxes. We have never had one back which we have examined and found to be dangerous.

At some point the F.I.E. insisted that all F.I.E. boxes have opto-couplying between any high voltage and low operating voltages.
So this will be being used in all the microprocessor boxes any shocks you get from these boxes are very low voltage.

One reason you might be geting shocks is using an old body wire, with leakage when you sweat. Try a brand new one.

Uhlmann F.I.E. boxes were originaly so well made that when you ran the point of the epee along the ground/piste the bouncing tip produced spikes which would trigger a valid hit. Instead of insisting that the box be changed the SEMI introduced a rule about not testing the point on the piste or running the point along it during fencing. Now the other German boxes made by...?when tested showed a tendancy to give real double hit as a radom result either way or correctly as both.

Please accept my assurance that mains boxes are safe. Any danger comes from the incoming power feed. Just like any U.K. mains powered machine.

sparkymark567
-14th July 2003, 16:38
As some of you quite rightly point out, I may have gone a bit over the top with this one (well a lot actually).

As you have probably guessed by now, I do have a disliking to mains boxes. It seems that perhaps some of my comments were a little unjustified. My original post, was a way of venting my anger. As I did get a little annoyed with the shocks I was receiving from a mains box that I used a couple of weeks ago. Looking back on this, I was sweating rather a lot that night, as it was a particularly hot evening.

I don't think anyone will ever be able to convince me that mains boxes are a good thing, but you pay your money and take your choice so I guess it's up to the people who buy them. But, you could probably guess correctly as to which model I'd buy.

Sorry about that Barry (and all) must not get so wound up in future.

sparkymark567
-14th July 2003, 16:47
The model I'd buy b.t.w would be an LP battery one (not Ulhman).
I particullarly like the batteries in these, they seem to last for ages.

haggis
-14th July 2003, 17:58
No, I don't work for LP. My designation as Kingkenny's pal stems from some earlier comments on this board where I'd jokingly referred to his moderating as being a bit heavy-handed. Glad that you've calmed down a little about this. I certainly had never heard of anyone being seriously injured as a result of a mains box design and it turns out I was right. The reason I suggested that Barry was rather better informed on the topic was that he designs and manufactures fencing equipment for a living as head of a company that (to quote the blurb) produces the widest range of fencing equipment in the world. As far as I was concerned that made him a bit of an expert and therefor worth listening to.

Haggis

P.S. I don't anything useful about electronics so I have to rely on the expertise of others. I've also received some shocks when fencing and extremely sweaty but never felt like my life was in danger.

Barry Paul
-14th July 2003, 18:46
Sparky All comunication with Sue Grabbit Run have been stopped. When I first saw your posting I thought that it was in the tone I would have written 30 yeras ago (can I be that old). Over the top and aggressive.

Barry Paul M D Leon Paul