Hi Kevin,
Thanks, This means that for a PC (secondary GND is Earthed) all SECONDARY circuits not GND must meet 1. functional clearance and creepage to GND as per table 2M and or 2N, or 2. withstand the 500 Vac (or higher) dielectrical test, or 3. be short circuit safe as in 5.3.4c 1 and 2 will probably fail on a motherboard, on many places... How compliance will be achieved there ? Regards, Ing. Gert Gremmen, BSc [email protected] <mailto:[email protected]> www.cetest.nl Kiotoweg 363 3047 BG Rotterdam T 31(0)104152426 F 31(0)104154953 Van: Kevin Richardson [mailto:[email protected]] Verzonden: Thursday, May 31, 2012 11:11 AM Aan: ce-test, qualified testing bv - Gert Gremmen; [email protected] Onderwerp: RE: [PSES] EN 60950-1 INaccessible parts Hi Gert, Remember that clause 5.3.4 deals with 'functional insulation' only. It talks about the insulation between a SECONDARY CIRCUIT and an 'inaccessible' conductive part that is earthed for functional reasons. There needs to be some insulation where the inaccessible conductive part is earthed. If this were an earthed 'accessible' conductive part it certainly cannot be just 'functional' insulation between it and a SECONDARY CIRCUIT. In terms of 5.3.4 c), as I understand it, clause 5.3.4 gives you a choice of how to meet the functional insulation requirement, i.e. either a) or b) or c). Option c) can be chosen if it is likely that if by short-circuiting the SECONDARY CIRCUIT to an inaccessible conductive part either overheating or thermal damage may occur as per the two dot points in 5.3.4 c), then you can choose option c). If you so choose option c) then clause 5.3.9 details the criteria to determine compliance with 5.3.4 c). Best regards, Kevin Richardson Stanimore Pty Limited Compliance Advice & Solutions for Technology (Legislation/Regulations/Standards/Australian Agent Services) Ph: 02-4329-4070 (Int'l: +61-2-4329-4070) Fax: 02-4328-5639 (Int'l: +61-2-4328-5639) Mobile: 04-1224-1620 (Int'l: +61-4-1224-1620) Email: [email protected] or [email protected] URL: www.stanimore.com Confidentiality This material (this email including all attachments) may contain confidential and/or privileged information intended to be read or used by the addressees only. If you are not one of the intended recipients or you have received this material in error, any copying, disclosure, distribution, use of or reliance upon this material is prohibited. Please immediately notify Stanimore Pty Limited and delete/destroy all copies (electronic and hardcopy) of this email and all attachments. While the sender tries to ensure the accuracy of the information contained in this material, Stanimore take no responsibility for any actions taken as a result of receiving this material or for any consequence of its use. From: ce-test, qualified testing bv - Gert Gremmen [mailto:[email protected]] Sent: Thursday, 31 May 2012 5:43 PM To: [email protected] Subject: [PSES] EN 60950-1 INaccessible parts Anyone aware of what seems as a typo to me in EN 60950-1:2006 in par 5.3.4 it say that clearance and creepage distances for functional isolation must be respected for INaccessible parts ... Whats the sense of guarding the isolation to not accessible parts ???? At the same time, anyone understands what means 5.3.4c they are short-circuited when a short circuit could cause...... well, that seems evident, sounds like " green grass " to me: a pleonasm thus. Regards, Ing. Gert Gremmen, BSc [email protected] <mailto:[email protected]> www.cetest.nl - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. 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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://listserv.ieee.org/request/user-guide.html 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]>
