In message <08bfa5ada9462e4f96e4a31a270fc86b048f5...@usa0300ms02.na.xerox.net>, dated Thu, 25 Oct 2007, "Spencer, David H" <[email protected]> writes:
>I'm trying to determine whether to include measurement of interharmonics >as a requirement for EN 61000-3-12. > >EN 61000-3-12:2005 does not include a dated reference to IEC 61000-4-7. >Whereas the current version EN61000-3-2 listed in the OJ references >IEC61000-4-7:1993. The difference being measurement of interharmonics >or not, or as was explained a month or so ago on this list-server, the >difference between a measurement band width of 50Hz and 5Hz. > >As I understand, when the referenced standard is not dated, you are to >use the most current version. Correct. That is why many of us want IEC to use dated references, as CENELEC does (now). > >To further complicate matters (in my mind), IEC 61000-4-7:2002, Section >7, speaks to a "Transitional period." > >"The use of existing measurement instruments based upon the requirements >given in IEC 61000-4-7 (1991) continues to be permitted until the next >revision of this standard. ............." > It doesn't complicate, surely? It allows you not to include interharmonics. This is because their inclusion raises many more problems than was realised when the change of bandwidth was made. The concession will remain until a solution to all the unexpected problems has been found. >SO... >Hypothetically speaking, let's say I'm testing a product using >measurement equipment that is designed to include or disable (equipment >can test to both IEC61000-4-7:1993 and IEC 61000-4-7:2002) measurement >of interharmonics and a product fails to meet the requirements of >EN61000-3-12. However, when interharmonic evaluation is disabled the >product meets the requirements of EN61000-3-12. > >What is the compliance status of that product? > It complies, because if it was tested with the 1991 instrument, it would pass.. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk There are benefits from being irrational - just ask the square root of 2. 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 [email protected] 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 [email protected] Mike Cantwell [email protected] For policy questions, send mail to: Jim Bacher: [email protected] David Heald: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________
