>If I have four products >resting on a shelf, and then I decide to put them in a rack instead, >there is no change in the EMC situation, so no additional testing is >required.
Not true for identical equipment. Any single product was tested as a single equipment and interaction in the close field between single units is not part of the tests. The current EMC regulations do *NOT* consider combining multiple pieces at all. Radiation may (will) add up even if the signals are not in phase. Same for harmonics and conducted emissions. EMC regulation was not made with the idea that a consumer may combine multiple identical boxes in a rack. When buying a rack of equipment, the client may expect similar protection as when buying a single piece of equipment, and the Manufacturer is expected to have evaluated the consequences. This does however, not address the combination of multiple different Items in a rack. Technically more or less like to buying a IKEA rack and setting up a audio/video combination. In practice most equipment integrators make a mixture of different and identical types of products, and in that case CE+CE <> CE at all. Gert Gremmen Ce-test, qualified testing bv Van: [email protected] [mailto:[email protected]] Namens John Woodgate Verzonden: woensdag 28 oktober 2009 7:15 Aan: [email protected] Onderwerp: Re: certifying overall products vs. certifying individual constituant chassis In message <[email protected]>, dated Tue, 27 Oct 2009, peter merguerian <[email protected]> writes: > >For EMI, I know the physics tto ebeaches us that CE + CE does NOT equal >CE (i.e. one compliant chassis combined with another compliant chassis >does not assure a compliant combination of the two chassis). I have >war stories to corroborate this. > >Peter: You are 100% correct and I know a few people in this forum whom >I worked with in the past who can attest to this. True, but you have to apply that with insight. If I have four products resting on a shelf, and then I decide to put them in a rack instead, there is no change in the EMC situation, so no additional testing is required. -- 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 Help stamp out intolerance! - 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 <[email protected]> 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 <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]> - 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 <[email protected]> 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 <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
