Page 208 - Electrical Installation in Hazardous Area

172 Electrical installations in hazardous areas

those standards are, however, obsolete or withdrawn and they should not
be used for construction of new equipment. Where equipment complying
with both current and historic Standards is available, the equipment to the
current standards is always preferable.
The relatively large number of methods by which electrical equipment
may be protected has meant that a large number of Standards exist, and
it has been recognized that many of the requirements of these standards
are common. The standardization structure is therefore to have a general
Standard and a series of additional Standards which refer to the general
Standard for many of their requirements, but contain additional require-
ments particular to the method used to protect the equipment. These are
all European Standards and are structured as follows.

BS/EN 50014 (1993) - General requirements (see Chapter 8)

This is the general or common Standard and contains any requirements
which apply to more than one of the specific methods of protection. Its
requirements apply to all of the protection concepts (with the current
exception of ’n’), unless they are specifically excluded and should be
read in conjunction with all of the following individual protection concept
Standards. It is currently at its second edition stage which should supersede
the first edition, but equipment certified in accordance with this and one of
the subsidiary protection concept Standards cannot, as already described,
bear the Distinctive Community Mark referred to in Chapter 1, unless it
also satisfies the first edition of the Standard. Therefore, it will not have
free access to EU Member States (and EFTA States).
This, as already identified, is because Directive 76/117/EEC2 currently
refers to the first edition and the mark is controlled by the Directive, not
the Standard. Again, as already identified, work is in hand to modify
76/117/EEC2 and it is expected to allow the use of the second editions of
this, and its subsidiary Standards, for equipment relating to the Directive
in late 1996. A further complication which is preventing the activating of
the new Directive5 is the fact that there appear to be discrepancies between
the second editions of these Standards and the essential requirements given
in the new Directive. (As already stated, all new approach Directives carry
the essential safety requirements within them, unlike their older counter-
parts which referred to Standards). This means that third editions of These
standards will need to be produced and the production is expected to be
complete in late 1997. When published, equipment complying with the third
editions of these Standards will be deemed to comply with the Directive
and will consequently be able to carry the ’Distinctive Community Mark’
in accordance with the Directive’s provisions. The need for continuing with
the older Directive, 76/117/EEC2, will then cease to exist for new equip-
ment, although the older equipment will continue to be acceptable until the
beginning of the twenty-first century (see Chapter 1).