Warning of 'non-compliant'withdrawable switchgear
March 1st 2008 It is estimated that up to 60% of
withdrawable switchgear being
sold into the UK market is noncompliant
with the latest IEC
standards for electrical switchgear,
according to Siemens
Transmission and Distribution.
The warning comes at a time of
dramatic growth in the use of
withdrawable switchgear by UK
industry, due to its reputation for
ease of maintenance and
maximum service continuity.
Recently, withdrawable switchgear
has made a comeback as supplies
of the equipment have returned to
the UK and end users have begun
to appreciate its benefits.
However, experts at Siemens
Transmission and Distribution believe
that the cost of testing to ensure
compliance with the new IEC 62271-
200 standard has led a number of
suppliers to neglect to pursue
certification for their withdrawable
switchgear. The new regulations
focus on the issues of safety,
availability, maintenance and, in
particular places greater emphasis
on the control of internal arc faults
inside switchgear which can
adversely impact operator safety.
Although still an optional test, the
new IEC standard offers clear rules
about the performance of internal
arc tests and the criteria which must
be achieved to comply with the
regulations. More specifically, test
conditions are defined and are no
longer subject to agreement
between the equipment
manufacturer and the test laboratory
and internal arc classification is only
granted if all criteria are met.
To ensure maximum operator
safety, in the event of an internal arc
fault in compliant switchgear, all
covers and doors on the switchgear
must remain closed; no
fragmentation of the enclosure or
projection of small parts must occur;
no holes in the accessible sides of
the switchgear must occur up to a
height of two metres and vertical
indicators must not ignite due to hot
gases. Finally, the enclosure must
remain connected to its earthing
connections at all times. More articles from Siemens Moore Process Automation: | 
