Short question, long answer. First off, I erred when I said the ground plane had to be non-ferrous. That is the military paradigm only. Commercial usually uses galvanized steel hardware cloth. I sent out a mea culpa on this subject only moments after I had let fly my original flawed answer. But getting back to the mil situation:
Whether or not the ground plane makes any connection to the steel walls of a shield room has no effect on the conducted emissions. The parameters that count are the bond between EUT and ground plane, and the bond between LISN and ground plane. All the interaction is between these two items, and any other ground connection is superfluous. ---------- >From: [email protected] >To: [email protected], [email protected], [email protected] >Subject: RE: conducted emissions test setup >Date: Wed, Feb 23, 2000, 2:17 PM > > Ken, > > Commonly available shielded rooms are made from galvanized steel panels. > Does your comment mean that these chambers are not very good for the ground > reference for conducted emissions tests? > > Don Umbdenstock > >> ---------- >> From: Ken Javor[SMTP:[email protected]] >> Reply To: Ken Javor >> Sent: Wednesday, February 23, 2000 6:21 PM >> To: Muriel Bittencourt de Liz; Lista de EMC da IEEE >> Subject: Re: conducted emissions test setup >> >> >> The ground plane acts as a sink for common mode CE. Without it, you have >> an >> uncontrolled test. >> >> The ground plane should be non-ferrous. Cu or bronze or even Al will >> work, >> but you can solder to Cu and bronze, but not to Al. >> >> The ground plane is common with the green wire. >> >> The LISN must definitely be bonded to the ground plane. The analyzer is >> connected by virtue of the coax connection to the LISN EMI port. That is >> technically sufficient. >> >> The spectrum analyzer should have its power input sufficiently >> well-filtered >> to be able to share a power connection with the PC. If not, they can be >> fed >> from different circuits. The green wire should be common to both >> circuits. >> >> ---------- >> >From: Muriel Bittencourt de Liz <[email protected]> >> >To: Lista de EMC da IEEE <[email protected]> >> >Subject: conducted emissions test setup >> >Date: Wed, Feb 23, 2000, 8:32 AM >> > >> >> > >> > Hello Group, >> > >> > Reading CISPR 16 and CISPR 22, I had some doubts about the correct setup >> > for doing conducted emissions testing. I'd like to know if someone can >> > put a light on this subject. >> > >> > My questions are: >> > >> > - The "ground plane" is really needed? If I don't use one, my results >> > will be wrong? Or without a ground plane I'll be testing for the "worse >> > conditions"?? >> > >> > - The ground plane can be made of any metal? Or there are specified >> > ones? >> > >> > - The ground plane must be bonded to the GND connector of my mains? (my >> > outlet is three pins: P, N and GND) >> > >> > - If I understood, the ground plane will be my "reference ground", >> > right? >> > >> > - My testing equipment (receiver+LISN) must be bonded to this same >> > ground plane? The ground plane is bonded to the ground connector of my >> > mains? >> > >> > - I use a PC to collect the test data. Can it be feeded by the same >> > circuit that feeds the EUT+LISN? The ground connector of the PC (the one >> > that's in the three pin plug) should be at the same ground than the >> > ground plane? >> > >> > Thanks in advance and Regards! >> > >> > Muriel >> > >> > -- >> > 8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-)8-) >> > Muriel Bittencourt de Liz, M.Sc. - EMC Engineer >> > GRUCAD - Group for Conception & Analysis of Electromagnetic Devices >> > Santa Catarina Federal University - UFSC >> > PO Box: 476 ZIP: 88040-900 - Florianópolis - SC - BRAZIL >> > Phone: +55.48.331.9649 - Fax: +55.48.234.3790 >> > e-mail: [email protected] >> > ICQ#: 9089332 >> > >> > --------- >> > This message is coming from the emc-pstc discussion list. >> > To cancel your subscription, send mail to [email protected] >> > with the single line: "unsubscribe emc-pstc" (without the >> > quotes). For help, send mail to [email protected], >> > [email protected], [email protected], or >> > [email protected] (the list administrators). >> > >> > >> >> --------- >> This message is coming from the emc-pstc discussion list. >> To cancel your subscription, send mail to [email protected] >> with the single line: "unsubscribe emc-pstc" (without the >> quotes). For help, send mail to [email protected], >> [email protected], [email protected], or >> [email protected] (the list administrators). >> >> > --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators).
