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#1 Posted : 11 April 2003 10:17:00(UTC)
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Posted By Brian Jenkins A laboratory worker has brought a bench top centrifuge into the department, which is from the USA. It has a 2-pin type plug attached and requires 110V. I understand we could purchase a step down transformer that would supply this voltage, but I am concerned whether it would really pass a PAT test. My understanding is there will be no earth and therefore how can the system protect the user suitably from an electric shock. Apologies if I have missed something obvious, but any thoughts would be welcomed. Regards Brian.
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#2 Posted : 11 April 2003 11:52:00(UTC)
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Posted By Ron Young Surely this product should be CE marked by an authorised agent. This website will assist. http://europa.eu.int/com...uide/document/chap07.pdf
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#3 Posted : 11 April 2003 12:02:00(UTC)
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Posted By Jim Walker Brian, I work for a UK centrifuge manufacturer, I'm familiar with UK and USA systems & requirements having designed to both. I'll help if I can, contact me direct if you wish. To be honest I suspect the cheapest option is to chuck it in the nearest skip. What other USA equipment has he brought with him?
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#4 Posted : 11 April 2003 12:31:00(UTC)
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Posted By Jane Blunt Dear Brian This equipment may well not come up to the standards required, but identifying it as having no earth is not the critical factor. There is a whole class of British equipment without an earth - known as Class 2 equipment. This has reinforced or secondary insulation. You can recognise it by the double box symbol and the fact that the flex is flattened (because it only contains two wires!). The earth pin on the plug is frequently plastic, and is necessary in order to operate the spring-loaded shutters that are fitted to the live and neutral sockets. Jane
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#5 Posted : 11 April 2003 13:49:00(UTC)
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Posted By Brian Jenkins Thankyou for your help, I shall continue to delve. Thanks Jane for your comments - Unfortuanately the equipment is not Class II. I am increasingly inclined to ask them to remove it. Brian.
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#6 Posted : 11 April 2003 16:22:00(UTC)
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Posted By Geoff Burt Without a full description its hard to visualise but how can you tell it is not double insulated? Modern metal kettles are double insulated but unless you know what you are looking at they don't appear to be. If you use a transformer to step down the voltage, the output winding will be centre tapped to earth - giving 55V on each leg and a much reduced risk. In fact it could well be safer than using a 240V equipment! Rather than throw it away just post it on to me. Geoff PS: By the way what is a bench top centifruge?
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#7 Posted : 11 April 2003 17:01:00(UTC)
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Posted By Neil Pearson Geoff - I think it's a device for making your laboratory go round and round in circles and not get anywhere.
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#8 Posted : 11 April 2003 17:09:00(UTC)
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Posted By Geoff Burt In that case I don't need it - I've got a built in one already judging by the times I go round in circles. Geoff
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#9 Posted : 11 April 2003 17:12:00(UTC)
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Posted By Graham Bullough A bit of Friday afternoon frivolity: Surely a centrifuge is the Italian term for a shelter designed to accommodate a hundred people?
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#10 Posted : 11 April 2003 17:16:00(UTC)
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Posted By Geoff Burt Come on Graham, even I know you couldn't get 100 Italians on a bench top.
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#11 Posted : 11 April 2003 21:42:00(UTC)
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Posted By Stuart Nagle Food for though for those interested. A 'CE' mark only shows that the 'device' has complied with all the current EU standards applicable to it. It is not a standard in itself, and it should be born in mind that many British and American Standards are higher than EU counterparts.
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#12 Posted : 12 April 2003 10:24:00(UTC)
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Posted By Geoff Burt Also, my understanding is that CE marking is self certificated.
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#13 Posted : 14 April 2003 09:08:00(UTC)
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Posted By Jim Walker Not all CE marks are self-certificated, but yes in this case it could be. However you have to declare on the (self) certificate that the equipment is tested to a standard; with centrifuges this is IEC 1010 –1:2000 (General Requirements) and IEC 1010-2-20 Particular requirements for laboratory centrifuges. These are sitting on my desk at the moment and are about an inch thick. Additionally they then refer to (I estimate) 40-50 other standards which have to be ( I stress) understood. Briefly, to be competent in signing one of these is not a job for an amateur who has done a little PAT testing. That’s before you start on the Electromagnetic compatibility and the anti-rupture measures on the big fast machines – I’ve seen (not our machines I hasten to add) the results of a breakaway rotor flying 10metres and through a breeze block wall. By way of explanation of the complexity of the tests – if you were to get third party testing by say BSI, the current going rate for a fairly ordinary bench top centrifuge is around £15K. If it is to be used for blood banking etc it becomes a medical device (mandatory third party testing) the costs triple. This might explain the difference in the price of the machines made by the main players in this field who check each other’s equipment and report suspected breaches (Yes, it’s a nasty world, out here) and the tiddlers that come and go. One other thing – anyone who imports equipment into the EEC is responsible for adequate CE marking; even if the machine is perfectly safe there would be a technical breach. Hence my earlier suggestion to dump it.
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#14 Posted : 14 April 2003 10:20:00(UTC)
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Posted By Geoff Burt Jim 'However you have to declare on the (self) certificate that the equipment is tested to a standard; with centrifuges this is IEC 1010 –1:2000 (General Requirements) and IEC 1010-2-20 Particular requirements for laboratory centrifuges. These are sitting on my desk at the moment and are about an inch thick. Additionally they then refer to (I estimate) 40-50 other standards which have to be ( I stress) understood. Briefly, to be competent in signing one of these is not a job for an amateur who has done a little PAT testing.' I don't think that was the intention Jim. The question was purely about electrical safety eg under the EWR to maintain equipment so as to avoid danger. I don't expect amy person who checks electrical safety to be au fait with all of the equipment standards being tested whether it be a centrifuge, an electric drill or whatever. What this thread does indicate is how easily it is to take H&S into depths which were unimagined when the question was being asked. Just where do we stop? Geoff Burt
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#15 Posted : 14 April 2003 10:47:00(UTC)
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Posted By Brian Jenkins Once again thank you to everyone for their input. Although some of it is indeed beginning to go over my head, but I think the general answer is there. Therefore although not wanting to stop anyone's interest or thoughts on the subject - In answer to Geoff's question 'Where will it end' The centrifuge is to be removed. Many Thanks to you all, Brian.
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#16 Posted : 14 April 2003 10:48:00(UTC)
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Posted By Jim Walker Geoff, Where do we stop? Yes a difficult question. "Maintain to safe standard" as required by EWR assumes the machine was safe (via good design) in the first place. In other words you are looking for deterioration. The original question was one of aquisition of equipment designed for use is a very different environment. PA testing could not indicate a safe macine, in this instance. On the one hand I know from experience you cannot trust the CE mark as an indicator of a safe product. On the other hand it is impossible to be expert at everything. The only advice I can give is buy (in this case aquire)from reputable sources. Don't buy on cost alone - with the bean counters about, this is virtually impossible in itself. Remember what ol' John Ruskin had to say:" There is hardly anything in the world that some man cannot make a little worse and sell a little cheaper, and the people who consider price only, are this man’s lawful prey "
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#17 Posted : 14 April 2003 12:44:00(UTC)
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Posted By Geoff Burt Purely out of interest, how do US standards compare to ours. I would have thought, in a society with such a willingness to sue, that standards of equipment would have to be much higher than the norm. My only recent experience of the US is Disney in Florida where I felt the attention to safety was far and away superior to similar attractions in the UK. But of course this was at the customer interface level, I have no way of knowing what it was like behind the scenes regarding maintenance. Geoff
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#18 Posted : 14 April 2003 14:23:00(UTC)
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Posted By Jim Walker Geoff, They are pretty strict mainly for the reasons you suggest, they will sue anyone who gives them a chance. In the market we operate all equipment is third party certified otherwise it gets held up at customs, the Americans assume everything foreign is iffy and everything USA made is OK. There is a North American treaty (Canada /USA/Mexico) that allow each other’s standards to be used. We use CSA (Canadian standards) to get in, mainly because I “know” the requirements better than UL (USA std) and it is easier to get testing in the UK. The safety aspects applied are now very similar for all of our world markets, even China is specifying the EEC Medical Equipment directive requirements for their Blood banking Centrifuges. USA H&S at work law is far more prescriptive and their version of HSE are real fascists, however it wouldn’t take long for a UK H&S competent person long to gain competence as the principles are the same. The equipment safety standards traditionally veer towards fire risk, fewer deaths touching 115v than 240, but it is becoming more like ours. From a design point of view there is not much difference in the safety methods used, except the fusing is in the distribution board not the plug or the equipment. In a non-domestic situation there are about 10 power variants all which have their own plug & socket style. It is easier, in my experience, to modify UK stuff to sell there, than the other way around. In an USA home, the power is generally 115volts 5amps with a few 240v (two 115V phases essentially) up to 20 amp outlets (usually hard wired) for the washing machine etc. The first thing that is noticeable in an USA home is the absence of electric kettles.
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#19 Posted : 15 April 2003 08:29:00(UTC)
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Posted By Jane Blunt This puts me in mind of a kettle that we confiscated here on an inspection. It had two red wires and one black wire to the plug - all clearly visible because the outer insulation had frayed away. Guess which one was intended to be the earth! Not all countries have the same colour codes! Jane
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#20 Posted : 22 April 2003 13:22:00(UTC)
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Posted By Hilary Charlton What was the question? I think to get back on track that the question here is not are US standards higher or lower than UK standards, does it need earthing, what is CE marking, what is EMC and Low Voltage spex and so on, the question is "do you feel confident and competent to work with the equipment and allow your staff to do so?" if the answer is "no" which I strongly suspect, then dump it! Hilary
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#21 Posted : 15 May 2003 18:51:00(UTC)
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Posted By Margaret I am often in the USA and not only do I find more stringent rules on Electrical safety but Electrical workers there actually know the real hazards of electrical shock injury unlike our U.K. counterparts. USA also has several Electrical trauma centres around the country as does France Germany and such like. Give me the name of one such Electrical Trauma Emergency Centre here in the UK with even 1 fully qualified doctor. I doubt that you can find one.
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