Muriel, this is a very question, and I'll let better qualified people answer your specific concerns.
Now, if I may add my 2 cents worth of experience in a 'similar' situation that involved conducted emission on SIGNAL leads: Under certain conditions, when the required CDN does interfere with signal template (such as T1) and affected equipment functionality, we used a current clamp. The danger of those networks interfering with the measurement/s & equipment exists and the test personnel should be aware of it. Season Greetings to all from (already) white Ottawa. Regards, Naftali Shani, Catena Networks (www.catena.com) 307 Legget Drive, Kanata, Ontario, Canada K2K 3C8 Voice +1.613.599.6430 X.8277 Fax +1.613.599.6433 E-mail: nsh...@catena.com or n...@ieee.org -----Original Message----- From: Muriel Bittencourt de Liz [mailto:mur...@grucad.ufsc.br] Sent: Friday, December 22, 2000 11:05 AM To: Lista de EMC da IEEE Subject: Doubt with conducted emissions measurement Hello Group! First of all, I wish a merry christmas and a happy new year for the list members. Second, I'd like to solve a doubt. It concerns the methodology of conducted emissions tests. Let's suppose a power electronic equipment (static converter) that has a boost converter in the entrance that's used for power factor correction (PFC). When I make a conducted emissions test, I plug the converter in a LISN, then I plug the LISN in the outlet, this way (the classical way): Equipment => LISN => Outlet (Mains) Well, the LISN consists of a RLC network that has the purposes of: - prevent that external interference from the mains contaminate the measurement - create a stabilized impedance (50 ohms) in the frequency range of interest (150kHz-30MHz) to make results repeatable, from site to site. Ok, what I've said until here is well known and is present in every book about this subject of EMC. My doubt is this: The LISN can't interfere in the functional operation of the converter? Things like resonance, extra ripple can't occur? And, imagining the worst scenario, can the LISN make my equipment not work according to what's expected? Another thing I was thinking about is the fact that the military tests os conducted emissions are done with a probe, and not using a LISN. I'm very curious about this subject because I was asked about this question and I became very surprised, because I have never thought about this. We are, generally, so interested in results that we forget to ask the "basic questions" sometimes. Well, I think that's all. Thanks in advance for those who can help me. Best Regards %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Eng. Muriel Bittencourt de Liz EMC Testing and Troubleshooting Group of Conception and Analysis of Electromagnetic Devices Federal University at Santa Catarina Florianópolis, SC, Brazil ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson: pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson: pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
