Re: [PSES] standard for power suply for server room.

[Doug Powell]

Can it be that the output is indeed floating and nominally +/- 375V?  If you use this, some sort of fault detection would be required to shut down if either end point becomes grounded. Sometimes this get tricky if the fault detection can be shown to fail in an unsafe way.  If achieved, you can use 600V wire on each output line..  All the best, Doug From:bostjan.gla...@siq.si Sent:September 20, 2016 10:10 PM To:EMC-PSTC@LISTSERV.IEEE.ORG Reply-to:bostjan.gla...@siq.si Subject:[PSES] standard for power suply for server room. Dear experts I again need your opinion on below issue.   Customer was asked for development of power supply which will be used to supply a  server in data centre. Input to power supply is defined as 750VDC. Unfortunately no information is available how this DC supply voltage is generated and reference to PE. Most probably it will be floating.   Now the problem, what standard to use for such product?   -          Standard IEC 60950-1 which is most often used is limited to 600V rated voltage. Does it mean 600VRMS? Is it then allowed to approve also products with 600xsqrt(2)=848VDC  rated voltage according IEC 60950-1 or limit is also set to 600VDC? Where this limit actually comes from? If you check requirements for clearance and creepage distance they go quite higher than 600V. -          Standard IEC 62477-1 could be appropriate standard however problem is that this standard is not worldwide harmonised and therefore no national certificates (US/CAN, China) are possible based on report according to this standard -          What other standard would be OK for US/CAN?   I appreciate your feedback.   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 <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> - ---------------------------------------------------------------- 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>