Dear experts, I have a question with regard of requirements in UPS standard IEC 62040-1/A1 and UL 1778.
There are listed options how to waive short-time withstand current testing, however these options in UL 1778 standard are different from one in IEC 62040-1. Client would like to fulfil exceptions from both standards. See below exceptions from the standards IEC 62040-1: UPS protected by current-limiting devices having a cut-off current not exceeding 17 kA with the maximum allowable prospective short-circuit current at the terminals of the incoming circuit of the UPS. UL 1778: UPS marked with a short-time withstand rating equal to or less than the lowest rated current limiting protective device in the UPS that does not exceed 10 kA Question is, can manufacturer list on the type label and specification cut-off current 17 kA and fulfil both standards without performing short-time withstand current test? My understanding is, that 10 kA in UL 1778 represents rms value while 17 kA in IEC standard represents peak value at which current limiting device cuts off fault current. Thank you for your support. Best regards, Bostjan - ---------------------------------------------------------------- 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]>
