High-voltage switchgear and controlgear - Part 304: Design classes for indoor enclosed switchgear and controlgear for rated voltages above 1 kV up to and including 52 kV to be used in severe climatic conditions
This part of IEC 62271 applies to indoor enclosed switchgear and controlgear complying with
IEC 62271-200 and IEC 62271-201, intended to be used in service conditions more severe
with respect to condensation and pollution than the normal service conditions specified ~n
IEC 62271-1.
This technical specification covers equipment where any of the insulation is exposed to indoor
climatic conditions.
The test detailed in this technical specification has been designed primarily to investigate the
behaviour of electrical insulation and not corrosion on equipments. Nevertheless, the
performance of mechanical components, such as mechanisms, interlocks and enclosures may
also be recorded.
This technical specification proposes definitions for two degrees of severe service conditions
with respect to condensation and pollution. It also proposes test procedures for assessing the
performance of enclosed switchgear and controlgear under specified conditions so that
conclusions may be drawn concerning their suitability for service under those severe service
conditions.
In this technical specification, the term "equipment" is used in accordance with the scope for
an "enclosed assembly of switchgear and controlgear" (see IEC 60050-441, definition 441-12-
O2).
NOTE The testing procedures described in this technical specification may also be applied to internal msulabon of
outdoor equipment.