Hi Bob: You wrote: > You are correct about the inrush requirement. It does not have to > be more than 500A for the voltages mentioned, but it also does not > have to be more than the margin required above the actual EUT inrush > current.
In IEC61000-4-11:2004, information about testing the AC source for peak current capability was moved from clause 6.1.2 to clause 6.1.1. See page 27, in the paragraph starting "When it is believed that a generator . . . ". The amount of margin in the paragraph hasn't changed. It still says the EUT inrush must be less than 70% of the generator capability. Sorry, my in-line arithmetic was probably confusing. Pat Lawler EMC Engineer SL Power Electronics Corp. [email protected] wrote on 05/20/2008 04:04:56 PM: > I'm looking at edition 2, dated 2004-03, and it appears the wording > has not changed. > > You are correct about the inrush requirement. It does not have to > be more than 500A for the voltages mentioned, but it also does not > have to be more than the margin required above the actual EUT inrush > current. We don't, at the present time, have the required fixture > (rectifier and capacitor)necessary to measure the output of the > power supply. I'm sure we can build it, but does anyone know of a source? > > Thanks, > Bob Richards, NCT > --- On Tue, 5/20/08, [email protected] <[email protected]> wrote: > > From: [email protected] <[email protected]> > > Subject: Re: 61000-4-11 Inrush current > > To: [email protected], [email protected] > > Date: Tuesday, May 20, 2008, 3:00 PM > > Hi Bob: > > > > I have a copy of IEC61000-4-11:1994. Take another look at > > clause 6.1.1. > > It says the peak inrush current drive capability '... > > need not exceed 500A > > for 220V-240V mains, or 250A for 100V-120V mains.' > > > > For a minimum capability, look at clause 6.2.2. It says > > that 'the > > measured EUT peak inrush current shall be less than 70% of > > the peak > > current drive capability of the generator, ...' > > Ipk.EUT < 70% * Ipk.generator > > Solving for Ipk.generator gives: > > Ipk.EUT * 143% < Ipk.generator > > Note the special test conditions for measuring the EUT peak > > inrush current in Annex A. > > > > So your generator needs to be capable of a peak current > > between Ipk.EUT * 143% and 500A. > > > > As far as your 'AC fault' information is concerned, > > ask your associate > > where it is documented. > > > > Pat Lawler > > EMC Engineer > > SL Power Electronics Corp. > > > > [email protected] wrote on 05/20/2008 05:11:26 AM: > > > A question came up recently where I work about the > > current > > > requirements of the AC source used for testing voltage > > dips and > > > interrupts. I was told the scope of the standard is > > for products up > > > to 16A and that *includes* inrush current during > > turn-on. > > > > > I referenced table 6.1.1 where the peak inrush current > > capability > > > must be 500A for 200 - 240v mains voltage, but was > > told this table > > > only covers AC fault conditions, not normal operations > > (including > > turn-on). > > > > > Since one of the tests is a >95% interruption for 5 > > seconds, would > > > this be considered an AC fault, or a normal turn-on > > for the EUT? > > > Appendix A sure makes it sound like the inrush > > requirement is for > > > the power-up of the EUT. > - > ---------------------------------------------------------------- > 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
