In the USA, at the load end of a 2-meter #18 power cord, you can expect 100-200 amps short-circuit current, but not more, due to the resistance of the power cord, the connectors, and the wiring to the breaker box.
If you assume that the source resistance is almost 1 ohm, the short-circuit current would be 120 amps, maybe down to 0.6 ohms and up to 200 amps (for a 120-volt system). The resistance of the 230-volt system will be more because the building wiring is smaller than North America, so the short-circuit current would be about the same. Rich -----Original Message----- From: Brian O'Connell [mailto:[email protected]] Sent: Monday, November 20, 2017 10:26 AM To: [email protected] Subject: Re: [PSES] Regulatory requirements for MOVs placed line-to-ground on AC mains ports? Mr. Woodgate, Is there a recently published spec for a 'typical' 230V mains impedance for the EU? Have also noted that the source Zs in 61000-4-5 for the instrument seem rather high. So what is the basis for 1500A interrupt rating? For U.S., even for an artificially low-Z electronic AC source, seldom see fault currents exceed 200A peak for 120V mains. Conversely, have noted that at over 100A fault current, any fuse not rated for the 'high' interrupt value will probably explode. So either our ratings are suspect, or perhaps the physics behind the standards are not complete? Brian - ---------------------------------------------------------------- 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 <[email protected]> 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 <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
