In message <7861714BC9794A2C8FE39FAD9F42BC3C@MmPc21>, dated Thu, 13 Nov 2008, Piotr Galka <piotr.ga...@micromade.pl> writes:
>I have in mind the open (without case) boards question just from the >beginning of my interest in EMC (2 years before we joined EU in 2004) >because since 1992 we have in our offer the microcontroller education >system with some open boards connected when needed. After reading old >Directive and its guide and later the new Directive and its guide I am >still not sure if after 2004 we sell it legally or not and designing >new (this time analogue) education system I'd like to be sure. I have given your case some more thought and consulted one or two colleagues, because it discloses an omission in the official documentation, insofar as the special case of educational products is not addressed. Please understand that this is just my personal opinion and in no way could I guarantee that it will work. We have to go back, first, to a basic EMC principle, which is that a source of disturbance, however strong, is of no consequence if there is no potential victim equipment within the distance at which the disturbance phenomenon has declined to a negligible level. A second point is that in an environment under a single ownership, the responsibility of mitigating any interference between equipment in that environment rests with the owner. This must be so, because the EMC standards assume certain distances between source and victim, whereas an owner may place them very close together. So you don't have to worry about a TV in a room next to the electronics lab - the TV may have to be moved. The Directive requires you to produce an EMC assessment. The following information, with the reasoning behind it, should be included in the assessment. As regards the first point and the emissions from your equipment, you should specify a minimum separation of, maybe, 10 m between the equipment and sensitive equipment such as TVs not owned by the users of your equipment. For ESD, you should specify that ESD precautions MUST be taken, because the equipment is INHERENTLY sensitive to ESD and cannot be rendered immune while serving its intended purpose. Then you use the procedure given in Annex III of the 2004/108/EC Directive to get a formal acceptance of your solution by a Notified Body. You can then, under Article 7, apply the CE mark. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk Either we are causing global warming, in which case we may be able to stop it, or natural variation is causing it, and we probably can't stop it. You choose! John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
