From: "bob" <[email protected]>
Subject: Re: Trace Spacings for PSTN Interfaces ...

I  agree   with  Vic,   I  would  like  to  point  out  you  may  already
know  that  though,  ITE   has  to  comply   with   creepage  and
clearances  as  stipulated  in  UL-1950  for  USA   and   CSA-950.  However,
those  equipment/devices  which  has  TNV   circuits has  to  comply  with
the  UL-1459  in US  and  corresponding  standard   for   Canada.  And   for
European  countries  it  is  covered  in  EN60950.  There  was   a  news
about   UL  being  working  on  a  unified  standard  which  shall  be
applicable  to   NAFTA,   actually  it  was   merger  of  two  standards
UL-1950 and  UL-1459  for  USA.  Could  somebody   supply   more
information on  this  topic?

In  addition,  there   are   some   subclauses in  UL  standards,  discussed
above   which  allow  deviations  until   year  2000,  and  after  that  one
must  adhere  to  tables   given  in  these  standards.  Does  this  mean
devices   built  now but  in  service  after   2000  has  to meet   the
requirements without  deviations  as  of  today?

Your  input  shall  be  appreciated,  Somm  may not  get  this  mail  due to
the  block  placed  by  their  bosses  on  access  to  this  treggers
forum!!!!!


http://www.microvolt.com/
Information is  the   key  to success.
-----Original Message-----
From: Victor L. Boersma <[email protected]>
To: INTERNET:[email protected] <[email protected]>
List-Post: [email protected]
Date: Monday, January 26, 1998 5:20 PM
Subject: Trace Spacings for PSTN Interfaces ...


> In other words, we aren't using the creepage/clearance
> tables of say UL-1950 3rd Ed. to determine the distances,
> or are we?

The cost of doing independent creepage and clearance research
is prohibitive.  At one time Bellcore may have done some, but I believe
that they have now accepted IEC 60950.  I believe the same to be true
for most service providers in Europe and North America, hence, sticking
with UL-1950 should see you through.

Vic




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