I suspect the IEC 60725 impedance is at the service entrance, not through the breaker box, building wiring, connectors, and power cord. By the time all these resistances are taken into account, I suspect that the total resistance is at least twice that specified in IEC 60725.
Rich -----Original Message----- From: Ralph McDiarmid [mailto:ralph.mcdiar...@schneider-electric.com] Sent: Monday, November 20, 2017 10:42 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Regulatory requirements for MOVs placed line-to-ground on AC mains ports? According to IEC/TR 60725, 90% of customers in the UK and in Australia, will have electricity supply impedance less than or equal to 0.25 + j0.23 ohms. That according to a survey or residential service for 230V/50Hz That tells me that short circuit current would be at least 680A, but could be twice that value or higher for some customers Ralph McDiarmid Product Compliance Engineering Solar Business Schneider Electric - ---------------------------------------------------------------- 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.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
