There is some discussion within IEC regarding this verification process which will be decided at the IEC MT 12 meeting in September in Sydney....
The consensus SEEMS TO BE (my opinion only) that it is necessary to verify each output independently to insure the output is present and correct at each output: i.e., each line to ground, one at a time. The test is then done common mode.... I agree that this is what should be done -- otherwise the output with all lines tied together may be fine, but with no output on one or more of the lines.... Don't believe anything official will happen until the September meeting.... Michael Hopkins International Channel Manager Thermo Fisher Scientific One Lowell Research Center Lowell, MA 01852 Tel: +1 978 275 0800 ext. 334 Fax: +1 978 275 0850 [email protected] From: [email protected] [mailto:[email protected]] On Behalf Of T.Sato Sent: Thursday, June 14, 2007 7:50 AM To: [email protected] Subject: RE: IEC 61000-4-4 ed.2, verification of CDNs On Tue, 6 Feb 2007 11:25:38 -0500, "Hopkins, Michael J." <[email protected]> wrote: > There is currently a corrigendum circulating to clarify this issue, > but the way it's currently written, it probably won't survive..... I found that the issue is now clarified in IEC 61000-4-4 Corr.2 ed. 2.0 (2007-06), as it now says: The waveform shall be verified at the common mode output of the coupling/decoupling network with ***all outputs tied together*** ... and the figure in the corrigendum tells us the same thing. It is exactly what I thought first, but I'm afraid that many of the old equipment will not pass this verification. Regards, Tom Tomonori Sato <[email protected]> URL: http://homepage3.nifty.com/tsato/ > -----Original Message----- > From: [email protected] [mailto:[email protected]] On Behalf Of T.Sato > Sent: Tuesday, February 06, 2007 9:17 AM > To: [email protected] > Subject: IEC 61000-4-4 ed.2, verification of CDNs > > Hello, > > Now, I have a question about interpretation of IEC 61000-4-4 ed.2 > clause > 6.2.2 about verification of CDNs. > > I believed that waveform at output of the CDNs must be verified for > the requirements in clause 6.2.2 of the standard, by applying the > pulse to all the lines simultaneously (e.g., L+N+PE), because IEC > 61000-4-4 ed.2 clause 6.2.2 says > > The waveform shall be verified at the ***common mode output*** > of the coupling/decoupling network with a single 50 ohm terminator. > ... > The functionality verification of each single coupling/decoupling > path is recommended. > > and it is also the injection mode to be used for tests. > > However, a test equipment manufacturer told us that they verify their > test generators / CDNs by applying the pulse to each of the lines one > by one (i.e., L only, N only, ...) and output voltage at output of > their CDNs may dropped significantly when pulse is applied to multiple > lines simultaneously, and the generators / CDNs are IEC 61000-4-4 ed.2 > compliant, even if the voltage at output of the CDNs are out of > tolerance when applied to multiple lines. > > My question is, is the manufacturer's interpretation correct? > > Does anyone here have information related to this issue? > > Regards, > Tom > > -------------------------------------------------- > Tomonori Sato <[email protected]> > URL: http://homepage3.nifty.com/tsato/ > > - > ---------------------------------------------------------------- > This message is from the IEEE Product Safety Engineering Society > emc-pstc discussion list. Website: http://www.ieee-pses.org/ > > To post a message to the list, send your e-mail to [email protected] > > 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 [email protected] > Mike Cantwell [email protected] > > For policy questions, send mail to: > > Jim Bacher: [email protected] > David Heald: [email protected] > > All emc-pstc postings are archived and searchable on the web at: > > http://www.ieeecommunities.org/emc-pstc - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. 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