BS EN 61558-2-7:1998 Incorporating Amendments Nos. 1 and 2 and Corrigendum No. 1

National foreword
This British Standard is the English language version of EN 61558-2-7:1997,
including amendment A11:2002. It was derived by CENELEC from
IEC 61558-2-7:1997.
The BS EN 61558 series of standards will ultimately supersede BS 3535-1,
dual numbered as BS EN 60742:1996, and BS 3535-2. Until that time arrives,
these latter standards are only to be used for equipment not covered by the
BS EN 61558 series.
The CENELEC common modifications have been implemented at the
appropriate places in the text.The start and finish of each common modification
is indicated in the text by tags ??. Where a common modification has been
introduced by amendment, the tags carry the number of the amendment. For
example, the common modifications introduced by CENELEC amendment A11
are indicated by ??.
From 1 January 1997, all IEC publications have the number 60000 added to
the old number. For instance, IEC 27-1 has been renumbered as IEC 60027-1.
For a period of time during the change over from one numbering system to the
other, publications may contain identifiers from both systems.