Gary Just a "top-up" on your message, and hopefully it might encourage you to "think again". The existing Machinery Directive - and specifically the Commission guidance document - and the forthcoming revised LVD clearly mention the issues of hazards arising from EMC issues. The Machinery Directive Guidance document clearly indicates that compliance with EMC Directive standards may not be suffient to ensure compliance with the machinery safety requirements - and I suspect that guidance documentation on the revised LVD may say the same when it is issued. For example, take a look at 1.5.11 (as shown below) in the Machinery Directive Guidance on http://europa.eu.int/comm/enterprise/me han_equipment/machinery/guide/annex1-15.htm "1.5.11. External radiation
Machinery must be so designed and constructed that external radiation does not interfere with its operation. General requirement Requirement 1.5.11 is a general constraint aimed not only at electromagnetic radiation but also at all other types of radiation. The aim is not to interfere with the operation of the machine. This aim is worded in general terms and obviously sets out to prevent any malfunctioning which might affect operator safety. It also concerns the "safety" of goods either involved in the production process of the machine or being stored nearby. The "safety" of goods and domectic animals is also one of the objectives of the "machinery" Directive even though it comes behind the safety of people. Requirement 1.5.11 can thus be seen as a general requirement of protection against radiation, covering all aspects of the matter, including industrial performance. This requirement reminds the designer that if the machinery can be used in certain environments or locations, he must select his components in such a way that the foreseeable conditions linked to the environment or location in question do not disrupt the operation of the machinery to the extent that operators or other persons are exposed to danger. To comply with requirements 1.5.10 and 1.5.11, the designer can take account of the standard EN 954-2 to make a control system safe in the presence of outside radiation of diverse origin." I think we can all conceive of situations where it can, and sometimes has, happened that EMI has caused machinery to malfunction with potentially disasterous results. Our company actually does a considerable amount of EMC planning and management work on large buildings and installations (e.g. the current extensions to Kings Cross railway station in London, parts of the London Underground System, and the new Terminal 5 at Heathrow airport) and it is a perenial problem that "CE Marked" equipment complying with specific standards is not necessarily suitable for the EMC environment where someone actually wants to install it. Therefore other factors, and sometimes even other (e.g. UK railway industry) EMC standards, come into play to in what is essentially a risk assessment, management and control exercise. Anyone who needs specific advice on these areas should contact my collegue David Atkey (+44-1372-367411) who specialises in this very area. Regards John Allen, Technical Consultant EMC and Safety Engineering ERA Technology Ltd. Cleeve Road Leatherhead Surrey KT22 7SA UK Tel: +44-1372-367025 (Direct) +44-1372-367000 (Switchboard) Fax: +44-1372-367102 From: Gary McInturff [mailto:[email protected]] Sent: 26 May 2004 16:19 To: EMC-PSTC (E-mail) Subject: CE and GS Thank you and small caveat Ladies and gentlemen, Once again you've made me happy that I subscribe to this list. Excellent responses and opinions from a wide range or responsibilities. I do appreciate it. I haven't had a chance to read all of the respondents yet, there were a quite a few, but I wanted to express my appreciation to you all. I'm not disagreeing with the need for the EMC directive or the LVD - quite the contrary. I simply don't want needless roadblocks (well at least as I see them to be roadblocks). Each of the directives does a good job at addressing their areas of concern and I don't see the need for a vendor to attach new requirements. Gert had a very interesting comment about EMC addressing safety. He noted that the EMC directives may under represent the safety issue, and I'm going to continue to think that over, but for the moment I differ slightly in opinion. There are essentially two parts to that test - 1) can what leaves the equipment disturb the public airwaves etc, and 2) can the equipment operate without significant disturbance in operation when subjected to the various noise, spikes, dips et al that is anticipated will see in the electromagnetic atmosphere in which it operates. I would claim that part two does address safety, albeit indirectly. The safety organizations are charged with investigating the hazards with normal and some abnormal operating conditions. If that is true, and the EMC directive says that the thing will operate "normally" when subjected to the immunity tests, or to phrase it differently it will not change normal operating states under anticipated EMC stresses, so if it doesn't change operating states and the safety folks have done a thorough job of investigating its safety performance the job is complete, and in fact the EMC directive has addressed safety. Thanks again Frauline and Frau (Hopefully ladies(y) and gentlemen(man) - other than being multilingual in pronouncing beer I've just run out of my German Gary _____________________________________________________________________ This e-mail has been scanned for viruses by MCI's Internet Managed Scanning Services - powered by MessageLabs. For further information visit http://www.mci.com ********************************************************************** Copyright ERA Technology Ltd. 2004. (www.era.co.uk). All rights reserved. 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