Doug Beckwith <[email protected]> wrote (in 
<[email protected]>) about 'IEC 
60950-1 2nd Ed', on Tue, 11 Oct 2005:
>I just read an article on IEC 60950-1 2nd edition in Compliance 
>Engineering, and I was wondering if the standard has actually been 
>released.

 From the public part of the IEC web site:

IEC 60950-1: work in progress

IEC 60950-1 Ed. 2.0 B BPUB [Being Published]
Information Technology Equipment - Safety - Part 1: General requirements

>
>One one of the changes I read about was that DC Hipot testing is no 
>longer allowed. Can anyone confirm that this requirement has changed in 
>the new standard, and if so, does anyone know the rationale for this?

It does not appear to be so. Part of clause 5.2.2 of the FDIS says:
QUOTE
Unless otherwise specified elsewhere in this standard the insulation is 
subjected either to a voltage of substantially sine-wave form having a 
frequency of 50 Hz or 60 Hz, or to a d.c. test voltage equal to the peak 
voltage of the prescribed a.c. test voltage.
ENDQUOTE
However, the standard is very complicated (can you say 'Byzantine'?), so 
the allegation may not be entirely unfounded.
>
>This has a huge impact on the testing of power supplies that have Y 
>caps to ground. It would in effect require disconnection of any caps to 
>ground, and this would dramatically impact production line testing.

OTOH, that would avoid over-stressing the Y-caps.
-- 
Regards, John Woodgate, OOO - Own Opinions Only.
Deadlines are 90% of deadliness.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

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