The method works quite well with testers designed using tapped transformers or variacs and relay switching. With these units ac power is taken from the local ac mains and generally not from an AC power source such as the California Instruments. Measurements done by the tester manufacturers and by companies using them can confirm that getting the proper in-rush current is not a problem.
Some years ago, we had an engineer go through our building after hours and measure available fault currents at wall sockets and he was able to get currents well in excess of the standard requirements at most locations. The problem with using most AC power sources for this standard is that many are not capable of supplying the required in-rush currents and most can't do the required 1 to 5us rise and fall times per section 6.1.1 "Characteristics and performance of the generator". By the way, most tester manufacturers have available units that contain the capacitor needed to measure the in-rush currents. These are generally made to plug in directly to the tester being tested, and some also have a BNC output connector for connection to a scope. Hope this is helpful. Maybe someone else can comment on AC power sources that may have sufficient in-rush current capability. Best Regards, Mike Hopkins EM Test Amherst, NH 603 769 3477 m.hopk...@emtest.com From: Mario Baraona Sr. [mailto:mbara...@atlasce.com] Sent: Wednesday, January 20, 2010 8:41 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Peak Inrush Current Capability Hello; This question is regarding the Peak Inrush Current capability of test generators per 61000-4-11, section 6.1.1, Table 4. We use a California Instruments 4801iL power source for Dips. We have to know what our test generator will provide. The test jig according the Annex A requires a 1700 uF, 400V Electrolytic Cap with an ESR of 0.1 ohms along with a current monitor characteristics as stated in Annex A. I would appreciate a response from anyone that preformed this verification and got the results as indicated per Annex A. I am not as comfortable with the results of my measurements. Is the ESR of 0.1 ohms that critical compared to a Cap with an ESR of more than this. Thanks, Mario E. Baraona Sr. Atlas Compliance & Engineering _________________________________________________ - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ 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 <emcp...@socal.rr.com> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ 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 <emcp...@socal.rr.com> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
