David - The battery voltage you mention at other than nominal -48 Vdc has often been referred to as "German battery." This CO battery voltage operates at a nominal -60 Vdc and is supposedly only present in telecommunication networks in a small region in parts of Germany and Austria.
Since your friend's product is CPE, it may not be necessary to design for the -60 Vdc battery applications. If your friend is willing to accept not selling in the region where -60 Vdc battery is present, they may follow an SELV design path without difficulty. Should your friend wish to include applications where -60 Vdc battery is used, they may design as if the input voltage were treated as either TNV-2 or Hazardous Voltage. There can be advantages to each design path, but which path is most cost effective depends largely on the overall design goals and functionality or services provided. Regards, Peter L. Tarver, PE [email protected] > From: David Gelfand > Sent: Thursday, August 31, 2006 1:43 PM > > Hello group, > > My question is more market-oriented than technical. A friend is > designing a -48Vdc powered voice over data product intended to be CE > marked, and sold in Europe and Africa. > > The debate has come up whether to design the input as SELV or > TNV-2. I > understand that in Europe, battery voltages can exceed 60Vdc, in which > case the input is considered TNV-2 and basic insulation is assured > between input and SELV circuits. > > However this will be customer premise equipment, not for network > operators. Are there other situations where battery voltages could > exceed 60Vdc apart from telco operators? > > His real questions are, > > Is it worth the extra expense to design in basic insulation? > If he declares the input as SELV only will he lose potential > customers? > > > Thanks in advance, > > David > > David Gelfand > Product Integrity > Mitec Telecom Inc > 9000 Trans-Canada Highway > Pointe-Claire, QC > Canada H9R 5Z8 > 514 694 9000 x2262 > CONFIDENTIALITY This e-mail message and any attachments thereto, is intended only for use by the addressee(s) named herein and may contain legally privileged and/or confidential information. If you are not the intended recipient of this e-mail message, you are hereby notified that any dissemination, distribution or copying of this e-mail message, and any attachments thereto, is strictly prohibited. If you have received this e-mail message in error, please immediately notify the sender and permanently delete the original and any copies of this email and any prints thereof. ABSENT AN EXPRESS STATEMENT TO THE CONTRARY HEREINABOVE, THIS E-MAIL IS NOT INTENDED AS A SUBSTITUTE FOR A WRITING. Notwithstanding the Uniform Electronic Transactions Act or the applicability of any other law of similar substance and effect, absent an express statement to the contrary hereinabove, this e-mail message its contents, and any attachments hereto are not intended to represent an offer or acceptance to enter into a contract and are not otherwise intended to bind the sender, Sanmina-SCI Corporation (or any of its subsidiaries), or any other person or entity. _____________________________________________________________________________ Scanned by Sanmina-SCI eShield _______ _____________________________________________________________________ - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] 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] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________
