A quick look through IEC 61000-4-5 shows a lot of references to an earth connection, but no ground plane except in the drawings regarding surging a shielded line between two pieces of equipment.
A 1.2/50us wave is considered to be relatively slow and low frequency compared to Electrical Fast transients and other RF testing, although as you say, it's much faster than the 50/60Hz used for -4-8. I don't think the ground plane was every seriously considered as a requirement for surge/lightning tests in -4-5 and hence carried over to -4-9. As for -4-8 that's always been the world of TC 77A which is low frequency, power related phenomena. I can only guess the need for a ground plane was removed since it's likely to have little or no effect on 50/60Hz fields inside a Helmholtz coil.... Best Regards, Mike Hopkins From: Pat Lawler [mailto:[email protected]] Sent: Wednesday, August 04, 2010 6:11 PM To: [email protected] Subject: Re: [PSES] 61000-4-8 vs 61000-4-9 GRP Hi Bob, OK, I'll stick my neck out. 1) Since the -4-9 test involves high frequencies (isn't it a -4-8 loop driven by a -4-5 generator?), maybe they feel the ground plane is needed for test repeatability. 2) Or, maybe they haven't gotten around to changing the -4-9 standard yet. They're managed by different groups: IEC 61000-4-9 is handled by TC 77B, while IEC 61000-4-8 is handled by TC 77A. I'm more curious as to why any effect was made to remove the ground plane requirement from -4-8. It seems like most EMC testing is already done over a ground plane. Pat Lawler EMC Engineer SL Power Electronics Corp. Bob Richards <[email protected]> wrote on 08/04/2010 10:48:23 AM: > Hmmm, no comments? > > --- On Tue, 7/27/10, Bob Richards <[email protected]> wrote: > > From: Bob Richards <[email protected]> > Subject: 61000-4-8 vs 61000-4-9 GRP > To: [email protected] > Date: Tuesday, July 27, 2010, 11:45 AM > > I just noticed the latest EN61000-4-8:2010 magnetic field immunity > test has done away with the ground reference plane for tabletop > equipment. This makes the test setup much easier. However, > EN61000-4-9:1993/A1:2001 appears to be the latest standard for the > pulsed magnetic field test, which has an identical test setup to the > previous version of 61000-4-8. Has there been any discussions about > changing the -9 test so it would have an identical test setup to the > -8 standard? This would make life easier when having to test a > product to both standards. > > On another note, what was the rational for the GRP in this test > anyway? And, why remove it? > > Bob Richards, NCT > > > - > ---------------------------------------------------------------- > 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]> - 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]>
