Hi all, Most immunity standards that I've seen (I work from EN 61326-1 in particular) specify a requirement for "Line to Line" and "Line to Ground" surges on the AC power lines. Typically, the line to ground test limit is twice as high as the line to line test limit.
What is typically done with ungrounded products? Is it. Choice A: All combinations of Line to Line and Line to Ground are tested even though the unit does not connect to the ground pin? Choice B: Only Line to Line surges are applied? I've read through EN 50142 (the BS version of IEC 1000-4-5); and it really doesn't specify either way. My basic instincts tell me that choice B is correct because, if there's no ground connection to complete the line-ground surge circuit; then there's no surge . But, one could reason that choice A is correct by saying that in real life, ungrounded products will be subjected to line to ground surge potentials even if they don't connect to ground. Such products, if poorly designed could have an insulation breakdown between line and ground under the surge potential, or they could be affected by the common mode components of the surge. Anybody care to help interpret, reason out or better yet, quote chapter and verse from a standard that would answer this question? Thanks, !!!!!!!!!PLEASE NOTE THE NEW EMAIL ADDRESS!!!!!!!! Chris Maxwell Design Engineer NetTest 6 Rhoads Drive, Building 4 Utica,NY 13502 email: chris.maxw...@nettest.com phone: 315-266-5128 fax: 315-797-8024 ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: pstc_ad...@garretson.org Dave Heald davehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on "Virtual Conference Hall,"
