I can fill in a little. It will be interesting to hear other historical
views.
EN60950 was copied from IEC 950
IEC 950 has been renumbered to IEC 60950 in line with the EC numbering
scheme.
IEC 950, Information Technology Equipment
First edition 1986
Amendment 1 Nov-88
Amendment 2 Jun-90
Second edition Sep 91
Amendment 1 Feb-92
Amendment 2 Jun-93
Amendment 3 Jan-95
Amendment 4 Jul-96
Third edition Any day now.
IEC 950 was the result of the merger of IEC 380 on business equipment,
and
IEC 435 on data processing equipment. Sorry, I don't have date histories
on
380 or 435. IEC 950 has recently incorporated telecom needs, deriving
much
from IEC guide 105, EN 41003 and UL 1459 into the standard starting
with
the second edition third amendment and expanded significantly in the
fourth
amendment.
IEC 435 was developed in the 1970s and inherited the aspects of a couple
cultures. In general terms, the fire control portions came from North
America, mostly out of UL 478, and the shock control portions came from
Europe, mostly from VDE standards.
The fire control portions seem to reflect the concerns in North America
of
largely wood construction which is quite sensitive to fire propagation.
UL
had previously developed a substantial base of flammability testing and
construction rules which were incorporated as flame resisitance ratings
and
enclosure requirements into UL 478.
The shock control seems to be driven from the increased risk of shock
from
higher mains voltages in Europe. Double insulation and the SELV circuit
concept was the primary means to improve shock risk.
At the same time IEC 950 was merging from its office and data processing
roots, UL was doing the same by merging UL 114, office equipment and UL
478,
data processing, into UL 1950, ITE. All use of UL 114 and 478 will be
ended
on 15 March 2000.
CSA likewise merged CSA 143, office equipment and CSA 154, data
processing,
into CSA 220. UL and CSA made a transition from their old formats to CSA
950
in the IEC 950 format (with deviations) in the current edition. CSA 143
and
154 expired on 30 September 1993 and CSA 220 on 30 September 1999.
EN60950 closely followed the IEC 950 schedule with:
First edition 1988
Amendment 1 1990
Amendment 2 1991
Second edition 1992
Amendment 1 1992
Amendment 2 1993
Amendment 3 1995
Amendment 4 1997
Third edition Also close on the heels of IEC 950.
Muriel Bittencourt de Liz wrote:
> Hello All,
>
> I doing a research that deals with EN standards. I'd like to know if
> someone has a brief historical of the changes from the early standards
> till actual standards (for example, IEC555 turned to IEC1000-3-2 and
> after EN61000-3-2). I'd like to know the reason for different naming and
> if possible the year of the changing...
>
> Thanks in advance for your help.
>
> Sincerely
>
> Muriel
> --
>
> ==================================================
>
> Muriel Bittencourt de Liz
> INEP - Instituto de Eletronica de Potencia
> Universidade Federal de Santa Catarina
> Caixa Postal - 5119
> 88.040-970 - Florianopolis - SC - BRASIL
> Phone: +55.48.331.9204 - Fax: +55.48.234.5422
> e-mail: mur...@inep.ufsc.br
> Homepage: http://www.inep.ufsc.br
>
> ==================================================
>
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