Right, typically the output supply bonding would be done outside the supply to make it PELV. The main question is whether the supplies meet the SELV criteria for keeping the output voltage limited under the internal fault condition if they claim compliance with UL 508 and EN 60950-1 but do not specifically mention anything about meeting SELV.
Or to re-phrase the other question, is there another standard that also specifically meets the requirements for SELV? Now you have me thinking, I should check the supply I have which does claim PELV and measure the impedance between the output and the PE terminal. -Dave -----Original Message----- From: John Woodgate [mailto:[email protected]] Sent: Thursday, September 04, 2014 2:35 AM To: [email protected] Subject: Re: [PSES] SELV/PELV power supplies In message <46b74057309b4f7e943f58221fd6d...@bn1pr08mb059.namprd08.prod.outlook.com> , dated Thu, 4 Sep 2014, "Nyffenegger, Dave" <[email protected]> writes: >With regards to electronic power supplies most data sheets I have seen >state compliance to UL 508 and EN 60950-1 but do not specifically >mention anything about meeting SELV or PELV requirements. Some do. The >question is it can somehow be assumed that an electronic power supply >compliant with UL 508 and/or EN 60950-1 and/or UL listed does in fact >meet requirements for SELV? The power supply as a whole cannot claim that unless ALL its outputs meet the SELV requirements. But it does meet the requirements for safety isolation, so those outputs that meet the voltage requirements are SELV. > Or is there another standard that also specifically meets the >requirements for PELV? I don't think so. It's up to you to convert an SELV output to PELV by connecting one side to the PE conductor. >Or does this need to be specifically confirmed with the manufacturer >beyond the basic UL 508 and/or EN 60950-1 if the data sheets do not >specifically claim a PELV rating? I doubt that you will find many power supplies that have PELV outputs (i.e. with one side connected internally to the PE). -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk Quid faciamus nisi sit? John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - ---------------------------------------------------------------- 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]> - ---------------------------------------------------------------- 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]>
