I believe the intention has always been to test line-to-ground (normal mode) and then neutral-ground (common mode). It's been a few years since I was convenor of that group and don't recall all the discussions. I believe coupling multiple lines may have been discussed, but there are real problems producing the proper waveforms for all conditions == especially for 3-phase systems where multiple lines can be involved in a common mode test. Of course, a product standard could require the line + neutral to ground tests, but I'm not aware of any that do. If they did, I wouldn't guarantee the waveforms to be correct from all generators under this condition. I believe that the single line to ground common mode test has been around since the old 801-5.
In the US, ANSI/IEEE and many companies take the position that the transient can come in any way it wants to, so line + neutral to ground is commonly (excuse the PUN) done. In section 8 of Edition 2 it's stated that for a.c. power ports five positive and five negative pulses each at 0º, 90º, 180º and at 270º shall be done.... So I'd say 180 IS a test as is 0 degrees... Note 2 of that section also states that, "Product committees may select different phase angles and either increase or reduce the number of surges per phase..." Hope this is helpful.... Michael Hopkins Amber Precision Instruments Office: +1 603 595 6420 Mobile: +1 603 765 3736 m...@amberpi.com From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Derek Walton Sent: Friday, March 06, 2009 11:22 AM To: IEEE EMC Discussion Group Subject: Surge testing Questions Good day folks, I have a question or two concerning the latest surge test document EN61000-4-5: 1) when the pulse is applied on a power lead between line and ground, is it done Line to ground, then Neutral to Ground OR, is it Line and Neutral to Ground. One would think if this were a common mode test ( since it's referenced to Ground ) that the pulse be applied Line and Neutral to ground simultaneously. However, the wording in -5 clause 8.2 states *successively *implying Line to ground then Neutral to ground. This implies separate tests. 2) On an AC waveform, is the 180 degree position a test condition? I ask because it states Zero crossing point. If this is NOT.... where is the exemption? Many thanks in advance. Derek Walton L F Research - 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...@ptcnh.net> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com> - 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...@ptcnh.net> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
