snip: In the case where a CDN is installed on each line from the EUT, how are the signal line shields handled at the EUT - left unterminated, terminated to ground, or terminated to the metallic case? snip
I am no expert on the specifics of EN61000-4-6. I like to think I have a good understanding of the physics of field-to-wire coupling. People reading that article I referred to may or may not agree with my self-assessment. With regard to the specific question above, I would assume, and I stress assume, that shield termination at the EUT would have to be production configuration. To me that is not the issue at all, but the real issue raised by the original question was grounding of the EUT chassis to the ground plane. That is what my paper talked about (in part). For those who are interested and do not have access to the symposium record, either hard copy or CD, I can send an electronic version in Word. Any recipient would have to swear not to reproduce it because it is copyrighted by the IEEE. Ken Javor > From: "Dan Kinney (A)" <[email protected]> > Date: Fri, 14 Feb 2003 17:13:06 -0500 > To: "'Ken Javor'" <[email protected]>, "Dan Kinney > (A)"<[email protected]>, Oliver Betz <[email protected]>, > [email protected] > Subject: RE: Grounding of EUT in EN61000-4-6 conducted immunity test > > Thanks for the quick response. Please let me explore this further. I have > used the "special case" as the general case where the EUT has many signal > lines in which it would be too costly and impractical to have a CDN on each > line. The special case allows the test engineer the flexibility of > disregarding the multiple impedances by way of the method described in the > body of the document and amplified in Annex A. I will admit I somehow > missed the point about the lower impedance requirement of the AE. In the > case where a CDN is installed on each line from the EUT, how are the signal > line shields handled at the EUT - left unterminated, terminated to ground, > or terminated to the metallic case? EN61000-6-2 is the generic immunity > standard we use. It states the functional earth port of the EUT will be > tested using this basic standard. If the earth is to be lifted, how is this > possible? > > I was not a member of this community in 1997 thus do not have a copy of the > symposium record. Is it available on the IEEE site? > Thanks again for your quick response. > Dan Kinney > >> -----Original Message----- >> From: Ken Javor [SMTP:[email protected]] >> Sent: Friday, February 14, 2003 4:41 PM >> To: Dan Kinney (A); Oliver Betz; [email protected] >> Subject: Re: Grounding of EUT in EN61000-4-6 conducted immunity test >> >> I was working off IEC 1000-4-6 (1996), Figures 2 and 5b, which cover >> direct >> injection and show the EUT isolated above ground. Figure 6 shows clamp >> injection and EUT isolation above ground. What you are referencing is a >> special case in the annex when the cm 150 Ohm impedance cannot be met. >> The >> theory is, I believe, as I stated before. Incidentally clamp injection is >> fundamentally different than CDN injection. CDN injects line-to-ground, >> and >> clamp injects in series with the cable. The standard specifically says >> that >> when using a clamp installed between EUT and AE, the AE must be an equal >> or >> lower impedance than the EUT. This is opposite of what you want with a >> CDN. >> My paper covers that issue in detail. It appeared in the 1997 IEEE EMC >> Symposium record, page 479. >> >> Ken Javor >> > 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: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
