I believe that DT is the only carrier that uses -60Vdc CO's, but I think 
that it is only present in their older CO's.

It's not that hard to meet the requirements though - just maintain 1mm 
(40th) creepage & clearance between TNV-2 and SELV, GND, etc (up to your 
DC/DC's/opto-isolators/bridging caps) and make sure any bridging 
capacitors are physically large enough to have 1mm between the pads (Y 
rating is not required but anything smaller than a 1206 SMT cap is too 
small to maintain spacings).  Voltage rating on the caps is important 
too, I guess - pick according to proper NEBS reliability derating.

-And you may have to ensure that your DC/DC's are rated properly.

Best Regards,
Dave Heald

  ----- Original Message -----
  From: "Joe Finlayson" <jfinlay...@telica.com>
  To: "'EMC PSTC'" <emc-p...@ieee.org>; "'NEBS Newsgroup'"
  <n...@world.std.com>
  Sent: Thursday, April 03, 2003 2:39 PM
  Subject: C.O. Battery Voltages - EVERYWHERE



>I'm interested in obtaining information on the percentage of C.O.'s
>worldwide that are utilizing -60VDC as their battery voltage.  It is my
>understanding that a majority use -48VDC although some still use -60VDC.
>Any and all information/references would be helpful.  If there are
>references that are country specific or carrier specific, that would be
>valuable information as well.  Any charts/spreadsheets out there similar
>to the mains supply charts I've seen would be excellent.
>
>Thx,
>
>
>Joe
>
>*************************************
>Joe Finlayson
>Manager, Compliance Engineering
>Telica, Inc.
>734 Forest Street, Bldg. G, Suite 100
>Marlboro, MA 01752
>Tel: (508) 804-8212
>Fax: (508) 480-0922
>Email: jfinlay...@telica.com
>



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