I disagree with what I perceive is being stated here - that if any portion of a system has a connection to a long conductor, then all system-attached cables must be tested down to 150 kHz.
The purpose of the Annex B wording is to allow for basic physics to be applied to the limit - short cables are inefficient pick-up at low frequencies. It is the length of the individual cable-under-test which should drive the low-frequency cut-off limit. Ken Javor > From: "Oliver Betz" <[email protected]> > Date: Mon, 26 Feb 2007 11:30:21 +0100 > To: [email protected] > Subject: Re: Conducted immunity lower frequency > > Bob Richards wrote: > >> Twice recently I've seen where annex B of 61000-4-6 ed2.2 is >> referenced by someone and used as a reason for not requiring testing >> down to 150 kHz "since the cable is specified as being less than x >> meters in length". (Of course, this is after the EUT failed at a low >> frequency!) > > Was Annex B applied correctly? Only very special setups are subject > to higher starting frequencies, e.g. the keyboard attached to a > battery powered PC, never used with AC adaptor. > > Most devices are galvanically coupled to sources of low frequency > disturbances, in this case the starting frequency must not be raised. > > I read this from Annex B and it makes sense. > > Oliver > -- > Oliver Betz, Muenchen > > - > ---------------------------------------------------------------- > 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. 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 email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________
