In message <201001051019.o05aj8a9013...@hormel5.ieee.org>, dated Tue, 5 Jan 2010, Brian Jones <e...@brianjones.co.uk> writes:
> Anyone in Europe can suggest improvements to their national committees >that, subject to national agreement, could be proposed to CENELEC. I did just that, but the UK NC didn't submit them, even though they were largely accepted.(8-O( It's an over-simplification to define two environments, because that doesn't take into account low-frequency emissions (610003-2, -3, -11 and -12). This is what I sent to BSI as comments and counterproposals on a proposal to 'harmonize' environments: Comments The proposed definitions are too indirect, and in fact are circular, because the A and B limits are set according to one or more of the existing definitions of the classes. [snip] There are, or should be, two technical factors in the classification: For low frequency phenomena: is the electricity supply public or private? For high-frequency phenomena: are there likely to be broadcast radio or television receivers within 10 m? (See the Note to the CISPR 22 definition of Class B.) NOTE: These two factors have been addressed previously by R de Vré in submissions to CLC/TC210 shortly before his retirement. The application of these factors is not quite straightforward because these Classes are not used in standards for low frequency phenomena; in fact in IEC 61000-3-2, 'Class A' and 'Class B' mean something completely different. Counter-proposals Proposed definitions: Class A: products intended by the manufacturer to be used: - on private electricity supplies OR, when meeting certain requirements for low-frequency emissions - on public electricity supplies AND - in locations where broadcast radio or television receivers are not sited within 10 m. Class B: products intended by the manufacturer to be used: - on public electricity supplies (optionally, on private supplies as well) AND - in locations where broadcast radio or television receivers are sited within 10 m. I think these statements are quite explicit and unambiguous. At the very least, they may be useful guides. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK I should be disillusioned, but it's not worth the effort. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.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...@socal.rr.com> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
