IR and D/EW are affected differently by capacitance, tracking, and other things.
IR can be both qualitative and quantitative; that is, a measurement of the property of the insulator, as the test conditions and levels are all defined. IR is typically done within the rated or 'normal' operating conditions of the device. D/E W testing is qualitative, where only the test level is defined, where the test level is significantly higher than the 'normal' operating conditions. Typically specify IR test as part of the DVT for transformers, but not as part of production testing. When a manager or project engineer doubts my sanity, which is often, will refer to these references: www.dtic.mil/dtic/tr/fulltext/u2/726924.pdf https://library.ul.com/wp-content/uploads/sites/40/2015/02/UL_WP_Final_The-Dielectric-Voltage-Withstand-Test_v5_HR.pdf Brian From: John Woodgate [mailto:j...@woodjohn.uk] Sent: Monday, February 19, 2018 2:19 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Insulation resistance test Hello, Rich. This puzzles me: Or, it can fail the insulation resistance measurement yet pass the dielectric strength measurement. how can that happen? John Woodgate OOO-Own Opinions Only J M Woodgate and Associates www.woodjohn.uk Rayleigh, Essex UK On 2018-02-19 21:53, Richard Nute wrote: Or, it can fail the insulation resistance measurement yet pass the dielectric strength measurement. - ---------------------------------------------------------------- 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>