Thank you Joe Randolph for more info and extending your support. The question was for drafting new product design specification both from PS design as well as safety perspective.
I see that 60VDC system would require more attention towards, creepage/clearance, accessibility and dielectric strength requirement perspective. This is critical because the working voltage can go up to 72V which is over SELV limit. There are no PSTN terminals in the system. It is just for system working from 48V and/or 60V DC supply. Thanks and regards, Kannan From: Joe Randolph [mailto:j...@randolph-telecom.com] Sent: Tuesday, August 15, 2017 11:00 AM To: Kannan Dhamodaran; EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: [PSES] -60Vdc Telecom supply voltage Hi Kannan: When I first replied to your question I was away from my office and simply named the primary country (Germany) that I clearly remembered as using 60 VDC. Now that I'm back in the office, I pulled out my copy of the 1997 edition of ETSI document ETS 300 001 for the EEC and EFTA member countries in Europe. Chapter 1 of that document contains an attempt to describe the characteristics of the PSTNs that were in use by the member countries at that time. Following is what that summary says for the 23 countries studied: COUNTRIES THAT USED 60 VDC EXCLUSIVELY: Austria, Bulgaria, Czech Republic, Germany, Greece, Luxembourg COUNTRIES THAT USED 60 VDC IN SOME, BUT NOT ALL AREAS: Norway, Poland, Sweden I think there may be other countries outside of Europe that used 60 VDC at some point, but it would take some more digging in my files to locate that info. By the way, if your question is related to safety compliance, I don't think there is any practical difference between 48 VDC and 60 VDC. If your question is related to functional compatibility, I don't think there is much difference there either. While some countries use 60 VDC instead of 48 VDC, the ones that use 60 VDC typically limit their short-circuit current to levels that are no higher than what some 48 VDC systems can deliver. Most telephones and other PSTN terminal devices are more sensitive to the available current than the open-circuit voltage. If you still have questions on this topic, I would be happy to try and answer them. Joe Randolph Telecom Design Consultant Randolph Telecom, Inc. 781-721-2848 (USA) j...@randolph-telecom.com<mailto:j...@randolph-telecom.com> http://www.randolph-telecom.com From: Kannan Dhamodaran [mailto:kan...@india.tejasnetworks.com] Sent: Tuesday, August 15, 2017 12:36 AM To: EMC-PSTC@LISTSERV.IEEE.ORG<mailto:EMC-PSTC@LISTSERV.IEEE.ORG> Subject: Re: [PSES] -60Vdc Telecom supply voltage Thank you Joe Randolph and Bostjan for your information. I'm surprised many have not answered. Or maybe that's all the info available. Once again thanks to everyone in the group. Best regards, Kannan From: Joe Randolph [mailto:j...@randolph-telecom.com] Sent: Friday, August 11, 2017 9:22 PM To: EMC-PSTC@LISTSERV.IEEE.ORG<mailto:EMC-PSTC@LISTSERV.IEEE.ORG> Subject: Re: [PSES] -60Vdc Telecom supply voltage Germany has historically been 60V, and I believe they still are. Joe Randolph Telecom Design Consultant Randolph Telecom, Inc. 781-721-2848 (USA) j...@randolph-telecom.com<mailto:j...@randolph-telecom.com> http://www.randolph-telecom.com From: Boštjan Glavič [mailto:bostjan.gla...@siq.si] Sent: Thursday, August 10, 2017 11:43 PM To: EMC-PSTC@LISTSERV.IEEE.ORG<mailto:EMC-PSTC@LISTSERV.IEEE.ORG> Subject: Re: [PSES] -60Vdc Telecom supply voltage Hello Kannan, As far as I know it was used in Russia, however they switch now to 48VDC. In deed there are many different systems and somewhere they might still use 60VDC. Maybe also in some other ex-Soviet Union countries. Best regards, Bostjan From: Kannan Dhamodaran [mailto:kan...@india.tejasnetworks.com] Sent: Friday, August 11, 2017 5:10 AM To: EMC-PSTC@LISTSERV.IEEE.ORG<mailto:EMC-PSTC@LISTSERV.IEEE.ORG> Subject: [PSES] -60Vdc Telecom supply voltage Dear valued members, can you guide me on nations that uses -60Vdc supply for telecom installations? Appreciate your valued inputs in advance. Best regards, Kannan - ---------------------------------------------------------------- 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<mailto: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)<http://www.ieee-pses.org/list.html> List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org<mailto:sdoug...@ieee.org>> Mike Cantwell <mcantw...@ieee.org<mailto:mcantw...@ieee.org>> For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org<mailto:j.bac...@ieee.org>> David Heald <dhe...@gmail.com<mailto: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<mailto: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)<http://www.ieee-pses.org/list.html> List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org<mailto:sdoug...@ieee.org>> Mike Cantwell <mcantw...@ieee.org<mailto:mcantw...@ieee.org>> For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org<mailto:j.bac...@ieee.org>> David Heald <dhe...@gmail.com<mailto: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<mailto: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)<http://www.ieee-pses.org/list.html> List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org<mailto:sdoug...@ieee.org>> Mike Cantwell <mcantw...@ieee.org<mailto:mcantw...@ieee.org>> For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org<mailto:j.bac...@ieee.org>> David Heald <dhe...@gmail.com<mailto: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<mailto: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)<http://www.ieee-pses.org/list.html> List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org<mailto:sdoug...@ieee.org>> Mike Cantwell <mcantw...@ieee.org<mailto:mcantw...@ieee.org>> For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org<mailto:j.bac...@ieee.org>> David Heald <dhe...@gmail.com<mailto: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>
