IEC TS 62271-304:2008

IEC/TS 62271-304
Edition 1.0 2008-05
TECHNICAL
SPECIFICATION
SPÉCIFICATION
TECHNIQUE
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
Appareillage à haute tension –
Partie 304: Classes de construction pour l'appareillage d’intérieur sous
enveloppe pour tensions assignées à partir de 1 kV jusqu’à 52 kV inclus pour
usage sous conditions climatiques sévères

IEC/TS 62271-304:2008
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IEC/TS 62271-304
Edition 1.0 2008-05
TECHNICAL
SPECIFICATION
SPÉCIFICATION
TECHNIQUE
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
Appareillage à haute tension –
Partie 304: Classes de construction pour l'appareillage d’intérieur sous
enveloppe pour tensions assignées à partir de 1 kV jusqu’à 52 kV inclus pour
usage sous conditions climatiques sévères

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
P
CODE PRIX
ICS 29.130.10 ISBN 2-8318-9828-5

– 2 – TS 62271-304 © IEC:2008
CONTENTS
FOREWORD.3

1 Scope and object.5

2 Normative references .5

3 Degrees of severity of service conditions under condensation and pollution .6

4 Classification of enclosed switchgear and controlgear .7

5 Classification procedure .7

6 Test facilities and associated requirements .9

6.1 Climatic test room .9
6.2 Control requirements.9
6.3 Energizing facilities .9
7 Selection and arrangement of the equipment for test .9
7.1 Selection of the equipment .9
7.2 Arrangement of the equipment .9
8 Ageing test .10
8.1 Level 1 ageing test .10
8.2 Level 2 ageing test .11
9 Diagnostic procedure after ageing test .11
9.1 General .11
9.2 Electrical diagnostic procedure.12
9.3 Mechanical diagnostic procedure (optional).13
9.4 Evaluation .13
Annex A (normative) Climatic cycle.14
Annex B (normative) Climatic test room .15
Annex C (informative) Example of typical environment.16

Figure 1 – Flow chart for classification procedure .8
Figure 2 – Level 1 ageing test.11
Figure 3 – Power-frequency withstand voltage test with high humidity after ageing test .12
Figure B.1 – Climatic test room.15

Table C.1 – Example of typical environment .16

TS 62271-304 © IEC:2008 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________
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

FOREWORD
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Technical specifications are subject to review within three years of publication to decide
whether they can be transformed into International Standards.

– 4 – TS 62271-304 © IEC:2008
IEC 62771-304, which is a technical specification, has been prepared by subcommittee 17C:
High-voltage switchgear and controlgear assemblies, of IEC technical committee 17:

Switchgear and controlgear.
The text of this technical specification is based on the following documents:

Enquiry draft Report on voting

17C/402/DTS 17C/422A/RVC
Full information on the voting for the approval of this technical specification can be found in

the report on voting indicated in the above table.
This first edition of IEC/TS 62271-304 cancels and replaces the first edition of IEC/TR 60932,
published in 1988, and constitutes a technical revision.
This revised document has been basically changed to be updated to today’s use of high-
voltage switchgear and controlgear up to 52 kV.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all the parts in the IEC 62271 series, under the general title High-voltage switchgear
and controlgear, can be found on the IEC website.
The committee has decided that the contents of this publication wil
...