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
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
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Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
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2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
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3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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6) All users should ensure that they have the latest edition of this publication.
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.

9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
The main task of IEC technical committees is to prepare International Standards. In
exceptional circumstances, a technical committee may propose the publication of a technical
specification when
• the required support cannot be obtained for the publication of an International Standard,
despite repeated efforts, or
• the subject is still under technical development or where, for any other reason, there is the
future but no immediate possibility of an agreement on an International Standard.
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 will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• transformed into an International standard,
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
The contents of the corrigendum of January 2010 have been included in this copy.

TS 62271-304 © IEC:2008 – 5 –
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

1 Scope and object
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 in
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-
02).
NOTE The testing procedures described in this technical specification may also be applied to internal insulation of
outdoor equipment.
2 Normative references
The following referenced documents are indispensable for the application of this document.

For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
IEC 60060-1: High-voltage test techniques – Part 1: General definitions and test requirements
IEC 60068 (all parts), Environmental testing
IEC 62271-1:2007, High-voltage switchgear and controlgear – Part 1: Common specifications

– 6 – TS 62271-304 © IEC:2008
IEC 62271-200, High-voltage switchgear and controlgear – Part 200: A.C. metal-enclosed
switchgear and controlgear for rated voltages above 1 kV and up to and including 52 kV

IEC 62271-201, High-voltage switchgear and controlgear – Part 201: AC insulation-enclosed
switchgear and controlgear for rated voltages above 1 kV and up to and including 52 kV

3 Degrees of severity of service conditions under condensation and pollution

Indoor equipment installed inside a building or room and thus normally protected against the

outdoor climatic conditions may be subjected to condensation due to rapid temperature

changes and to pollution due to the environment inside the building.
The service conditions with respect to condensation and pollution around the enclosed
switchgear and controlgear are designated and characterized as follows:
C : Condensation does not normally occur (not more than twice a year)
o
• Equipment to be used in locations with humidity and/or temperature control in
order to avoid condensation. The building or room provides protection from daily
variations of outside climate.
C : Non-frequent condensation (not more than twice a month)
L
• Equipment to be used in locations without humidity and/or temperature control.
The building or room provides protection from daily variations of outside climate,
but condensation cannot be excluded.
C : Frequent condensation (more than twice a month)
H
• Equipment to be used in locations without temperature control. The building or
room provides only minimal protection from daily variations of outside climate, so
that frequent condensation may occur.
P : Light pollution (as given in 2.1.1, item d) of IEC 62271-1) (see note 2 below)
L
• In order to reach light pollution in heavy polluted locations precautions may be
necessary.
P : Heavy pollution (any value exceeding P )
H L
P does not include areas subject to conductive dust and/or to industrial smoke,
H
producing thick conductive deposits.
• The location has no special precautions to minimize the presence of deposits, or
the equipment is situated in close proximity to pollution sources.
NOTE 1 Absence of pollution is considered as unrealistic. At least light pollution is assumed.
NOTE 2 IEC 62271-1, 2.1.1, item d): “The ambient air is not significantly polluted by dust, smoke, corrosive
and/or flammable gases, vapours or salt. The manufacturer will assume that, in absence of specific requirements
from the user, there are none.”
NOTE 3 Precautions to minimize the amount of deposits inside the enclosure of the equipment may be taken by
the choice of an appropriate degree of protection of the enclosed switchgear and controlgear.
Taking into account the fact that the equipment is especially influenced by the combination of
humidity and pollution, three degrees of severity of service conditions are defined as follows:

TS 62271-304 © IEC:2008 – 7 –
Degree 0: C P
o L
Degree 1: C P or C P
L L o H
Degree 2: C P or C P or C P
L H H L H H
NOTE 4 Degree 0 correspond to normal service condition as described in 2.1.1 of IEC 62271-1.

4 Classification of enclosed switchgear and controlgear

Three design classes 0, 1 and 2 are defined. They essentially correspond to the three
degrees of severity of service conditions according to Clause 3.

5 Classification procedure
For the normal service conditions specified in IEC 62271-200 and IEC 62271-201, no
additional test is required. Standardized switchgear and controlgear complying with these
publications is considered as belonging to Design Class 0.
Satisfactory performance under severe service conditions of equipment complying with
Design Class 1 or 2 is verified by testing the equipment.
Enclosed switchgear and controlgear is considered to belong to Design Class 1 if it is
subjected to the level 1 ageing test according to 8.1 and satisfies the evaluation criteria of the
diagnostic procedure described in Clause 9.
Enclosed switchgear and controlgear is considered to belong to Design Class 2 if it is
submitted to the level 2 ageing test according to 8.2 and satisfies the evaluation criteria of the
diagnostic procedure described in Clause 9.
The level 1 and level 2 ageing tests require the repeated application of identical climatic
cycles followed by the diagnostic procedures specified in Clause 9. The level 2 ageing test is
identical to the level 1 ageing test except that for level 2 a greater number of climatic cycles is
to be applied.
This classification procedure is illustrated in the flow chart, Figure 1.

– 8 – TS 62271-304 © IEC:2008
Design Class 0
Level 1
Ageing test
Diagnostic
procedure
(See clause 9)
Fail
Pass
Design Class 1
Level 2
Ageing test
Diagnostic
procedure
(See clause 9) Fail
Pass
Design Class 2 Design Class 1 Design Class 0

IEC  845/08
Figure 1 – Flow chart for classification procedure

TS 62271-304 © IEC:2008 – 9 –
6 Test facilities and associated requirements

6.1 Climatic test room
A climatic test room is required which shall be of sufficient size to accommodate the

equipment to be tested. The equipment shall be installed in the climatic test room at a height

of not less than 0,5 m from the ground in a manner to permit the circulation of the ambient air.

The distance between walls and ceiling of the test room and walls and the top of the

enclosure of the equipment shall be more than 1,0 m. Precautions shall be taken to insure

that no condensed water from the walls and ceiling of the test chamber can fall on the
equipment.
Figure B.1 is an explanatory figure for the test room.
6.2 Control requirements
The temperature needs to be controlled within limits of less than ±3 K. During the tests, it
shall be varied cyclically between 30 °C to 50 °C. The temperature gradient shall be at least
0,5 K/min. The distribution of temperature in the whole volume of the chamber should be
within the same tolerances.
The humidity also needs to be controlled within close limits over a range from below 80 % to
over 95 % of relative humidity.
6.3 Energizing facilities
A three-phase high-voltage source shall be provided so that the equipment to be tested can
be energised during the test. The source used for this purpose shall be able to maintain the
rated voltage with a tolerance of 0 to –5 % during the climatic cycles. The voltage shall be
recorded continuously during the whole duration of the tests for the purpose of checking
possible disruptive discharges.
A source is required for applying diagnostic test voltages up to at least the dry power-
frequency withstand voltage of the equipment to be tested. This source shall have a protective
device operating in less than 0,1 s in the event of a disruptive discharge.
The sources shall comply with IEC 60060-1.
7 Selection and arrangement of the equipment for test

7.1 Selection of the equipment
Ageing test is to be made on a functional unit completely assembled and fitted with all its
components as for service, measuring transformers included. The functional unit and its
components shall be new and clean.
7.2 Arrangement of the equipment
The equipment to be tested shall be installed in the climatic test room, as given in 6.1, in its
normal service position. The test arrangement of the functional unit shall not be more
favourable than the normal service arrangement, especially in respect of the external
connections.
– 10 – TS 62271-304 © IEC:2008

Connection shall be made so that the functional unit can be energized from a three-phase
supply at its rated voltage.
8 Ageing test
8.1 Level 1 ageing test
The equipment shall be installed in the climatic test room and subjected during three identical

test periods of seven days, to 2 h damp heat cycles as follows (see Figure 2).

The temperature of the climatic test room is raised from 30 °C to 50 °C in 40 min, with the
relative humidity constantly above 95 %. These conditions are maintained for 20 min, and the
temperature is then lowered to 30 °C in 40 min, at any convenient value of humidity.
The temperature is then maintained at 30 °C for 20 min, and throughout this period the
relative humidity is kept above 80 %.
The test period of seven days duration is made up as follows:
For five days, the equipment to be tested is energised at its rated voltage and subjected to 60
damp heat cycles.The application of rated voltage means U between phases and U / 3
r
r
between phase and earth. After these five days the test is stopped at the end of the last cycle
at 30 °C. The equipment is de-energized. A visual inspection is made as far as possible
without dismantling the equipment in order to detect the inception of trackings on insulating
surfaces.
For two days, the equipment shall be maintained in an ambient climate close to the reference
atmosphere mentioned in IEC 60060-1.
After the completion of three test periods, the performance of the equipment shall be
evaluated in accordance with the diagnostic procedure specified in 9.2.

TS 62271-304 © IEC:2008 – 11 –

IEC  846/08
Figure 2 – Level 1 ageing test

8.2 Level 2 ageing test
The level 2 ageing test comprises a total of seven identical test periods of seven days,
followed by the diagnostic procedure specified in 9.2.
NOTE In the case where equipment has already been successfully subjected to the level 1 ageing test it is
permitted to continue the test immediately after the diagnostic test, applying four additional test periods.
9 Diagnostic procedure after ageing test
9.1 General
After the conclusion of the ageing tests, and reaching ambient temperature, the equipment
shall be subjected to dielectric tests as follows without any special treatment like cleaning,
extra drying, etc. The voltage transformers shall be disconnected.
Relative humidity uncontrolled
Relative humidity uncontrolled
Visual inspection Visual inspection
Relative humidity uncontrolled
Visual inspection
Visual inspection
(Dry) Power-frequency voltage test
Power-frequency voltage test at high humidity
(see figure 3)
– 12 – TS 62271-304 © IEC:2008

9.2 Electrical diagnostic procedure

The equipment is first subjected to the dry 1 min power-frequency withstand voltage test at its

rated value according to IEC 62271-1.

The voltage shall be removed and the temperature in the climatic test room shall be increased

to 30 °C and the humidity at least to 95 %. After 3 h in these conditions, the following

dielectric test is performed (see Figure 3).

One phase is energized at U / 3 , where U is the rated voltage of the equipment, the other
r
r
two phases being earthed and connected to the protective conductor of the equipment. After

1 h, the voltage is raised to 3 U for 30 s (voltage rise in accordance with 6.3.1 of
r
IEC 60060-1).
The test is repeated successively on the other two phases, the interval between the tests
being as short as possible. If the configuration permits, phase A and C may be energised
together. If all 3 phases are screened (fully separated by earthed partitions), they can be
energised together.
The degree of tracking shall be recorded in the test report.

Voltage
Phase A Phase B Phase C
30 s 30 s 30 s
3 U
r
1 h 1 h 1 h
U / 3
r
Time
IEC  215/10
Figure 3 – Power-frequency withstand voltage test with high humidity after ageing test

TS 62271-304 © IEC:2008 – 13 –

9.3 Mechanical diagnostic procedure (optional)

This diagnostic procedure is not set up to prove the mechanical and corrosion performances.

Nevertheless, the results of the test can give useful information. Specific procedures are

foreseen in the IEC 60068 series.

Mechanical operations shall be performed on the switching devices and on the doors of the

functional unit.
The following mechanical diagnostics may be applied if applicable: operating times, torque,

contact speeds, operation of interlocks, etc., and shall be recorded according to IEC 62271-1.

The degree of corrosion shall be recorded in the test report.
9.4 Evaluation
The equipment complies with the Design Class 1 or 2 if the following conditions are satisfied:
• no disruptive discharge has occurred during the climatic cycles according to the ageing
test;
• no disruptive discharge has occurred during the diagnostic procedure;
• if the option of 9.3 is chosen, the mechanical functional performances of the equipment
shall be within the permitted tolerances given by the manufacturer.

– 14 – TS 62271-304 © IEC:2008

Annex A
(normative)
Climatic cycle
A.1 Remarks on the climatic cycle

The climatic cycle described in this technical specification is the same described in the first

edition of IEC 60932. This climatic cycle has proved satisfactory for more than 15 years.

The aim of this climatic cycle is to produce condensation on the insulation parts of the
switchgear in order to prove the dielectric behaviour under this condition.
Condensation always occurs immediately when the temperature of the object is lower than the
dew point of the ambient air. The object described in 7.1 consists of several components with
their own thermal time constants. If the time constants of all components are long in
comparison with the half of the climatic cycle, the temperature of all components alternates
slightly around the mean temperature of the climatic cycles. Therefore the temperature of the
object is nearly half of the cycle below the dew point of the ambient air and condensation
occurs for this time at least.
A.2 Origin of the apparition of a conductive layer, produced by the cyclic
presence of condensation on insulating parts of high voltage switchgear
This explanation has been given by competent chemists working in collaboration HV test
laboratories, after proceeding to several analysis of deposits from insulating services having
been naturally exposed to condensation for years (in the network) or artificially for weeks
(method A of the first edition of IEC 60932).
Atmospheric air is essentially (78%) composed of nitrogen (N ). In presence of high voltage
(surface) discharges, and catalysed by UV radiation due to corona effect, some N combines
with H O from condensation, to produce small quantities of HNO and HNO .These acids
2 2 3
dissolved in H O react with metals like Al, Ag, Cu, or Fe and produce conductive nitrous salts,
which are deposited and concentrated in some places during drying. The presence of those
irregular conductive paths give way to tracking of the insulating surfaces. Nitrous salts have
been detected by spectrographic analysis of deposits on insulating surfaces after the
application of the method A.
When using method B of the first edition of IEC 60932, spectrographic analysis mainly
showed the presence of deposits of NaCl, small amounts of metal chloride salts and traces of
nitride salts. Chemical concentration was higher, but exposure time was much less.
Inter-laboratory comparison focused on usual epoxy insulating parts showed a good
relationship between the final results of application of method A and method B of first edition
of IEC 60932.
TS 62271-304 © IEC:2008 – 15 –

Annex B
(normative)
Climatic test room
The test object shall be placed in the test room with minimum distances to the walls as shown

in Figure B.1.
≥ 1,0 m
≥ 1,0 m ≥ 1,0 m
Test object
≥ 0,5 m
IEC  848/08
Figure B.1 – Climatic test room

– 16 – TS 62271-304 © IEC:2008

Annex C
(informative)
Example of typical environment

The following Table C.1 is intended to give examples of determination of the pollution level of

typical environment.
Table C.1 – Example of typical environment

Pollution level Example of typical environments
Light - Areas without industries and with low density of houses
equipped with heating plants
- Agricultural areas
All these areas shall be situated at least
- Mountainous areas
10 km to 20 km from the sea and shall not
be exposed to winds directly from the sea
Heavy - Areas with industries not particularly producing pollution smoke
and/or with average density of houses equipped with heating
plants
- Areas exposed to wind from the sea but not too close to the
coast (at least several kilometres distant)
- Areas with high density of industries and suburbs of large cities
with high density of heating plants producing pollution
- Areas close to the sea
___________
– 18 – TS 62271-304 © CEI:2008

SOMMAIRE
AVANT-PROPOS.19

1 Domaine d'application et objet.21

2 Références normatives.21

3 Degrés de sévérité des conditions de service sous condensation et pollution .22

4 Classification de l'appareillage sous enveloppe .23

5 Procédure de classification.23

6 Moyens d'essais et exigences correspondantes.25

6.1 Chambre d'essai climatique.25
6.2 Exigences de contrôle .25
6.3 Moyens d’alimentation.25
7 Choix et disposition de l'appareillage pour l'essai .25
7.1 Choix de l'appareillage .25
7.2 Disposition de l'appareillage.25
8 Essai de vieillissement .26
8.1 Essai de vieillissement de niveau 1 .26
8.2 Essai de vieillissement de niveau 2 .27
9 Méthode de diagnostic après l'essai de vieillissement .27
9.1 Généralités.27
9.2 Méthode de diagnostic électrique .28
9.3 Méthode de diagnostic mécanique (option).28
9.4 Evaluation .29
Annexe A (normative) Cycles climatiques .30
Annexe B (normative) Chambre climatique .31
Annexe C (informative) Exemple d’environnements typiques .32

Figure 1 – Diagramme de la procédure de classification .24
Figure 2 – Essai de vieillissement de niveau 1.27
Figure 3 – Essai de tension de tenue à fréquence industrielle sous forte humidité,
après essai de vieillissement .28
Figure B.1 – Chambre d’essai climatique .31

Tableau C.1 – Exemples d’environnement typiques .32

TS 62271-304 © CEI:2008 – 19 –

COMMISSION ÉLECTROTECHNIQUE INTERNATIONALE

____________
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

AVANT-PROPOS
1) La Commission Electrotechnique Internationale (CEI) est une organisation mondiale de normalisation
composée de l'ensemble des comités électrotechniques nationaux (Comités nationaux de la CEI). La CEI a
pour objet de favoriser la coopération internationale pour toutes les questions de normalisation dans les
domaines de l'électricité et de l'électronique. A cet effet, la CEI – entre autres activités – publie des Normes
internationales, des Spécifications techniques, des Rapports techniques, des Spécifications accessibles au
public (PAS) et des Guides (ci-après dénommés "Publication(s) de la CEI"). Leur élaboration est confiée à des
comités d'études, aux travaux desquels tout Comité national intéressé par le sujet traité peut participer. Les
organisations internationales, gouvernementales et non gouvernementales, en liaison avec la CEI, participent
également aux travaux. La CEI collabore étroitement avec l'Organisation Internationale de Normalisation (ISO),
selon des conditions fixées par accord entre les deux organisations.
2) Les décisions ou accords officiels de la CEI concernant les questions techniques représentent, dans la mesure
du possible, un accord international sur les sujets étudiés, étant donné que les Comités nationaux de la CEI
intéressés sont représentés dans chaque comité d’études.
3) Les Publications de la CEI se présentent sous la forme de recommandations internationales et sont agréées
comme telles par les Comités nationaux de la CEI. Tous les efforts raisonnables sont entrepris afin que la CEI
s'assure de l'exactitude du contenu technique de ses publications; la CEI ne peut pas être tenue responsable
de l'éventuelle mauvaise utilisation ou interprétation qui en est faite par un quelconque utilisateur final.
4) Dans le but d'encourager l'uniformité internationale, les Comités nationaux de la CEI s'engagent, dans toute la
mesure possible, à appliquer de façon transparente les Publications de la CEI dans leurs publications
nationales et régionales. Toutes divergences entre toutes Publications de la CEI et toutes publications
nationales ou régionales correspondantes doivent être indiquées en termes clairs dans ces dernières.
5) La CEI elle-même ne fournit aucune attestation de conformité. Des organismes de certification indépendants
fournissent des services d'évaluation de conformité et, dans certains secteurs, accèdent aux marques de
conformité de la CEI. La CEI n'est responsable d'aucun des services effectués par les organismes de
certification indépendants.
6) Tous les utilisateurs doivent s'assurer qu'ils sont en possession de la dernière édition de cette publication.
7) Aucune responsabilité ne doit être imputée à la CEI, à ses administrateurs, employés, auxiliaires ou
mandataires, y compris ses experts particuliers et les membres de ses comités d'études et des Comités
nationaux de la CEI, pour tout préjudice causé en cas de dommages corporels et matériels, ou de tout autre
dommage de quelque nature que ce soit, directe ou indirecte, ou pour supporter les coûts (y compris les frais
de justice) et les dépenses découlant de la publication ou de l'utilisation de cette Publication de la CEI ou de

toute autre Publication de la CEI, ou au crédit qui lui est accordé.
8) L'attention est attirée sur les références normatives citées dans cette publication. L'utilisation de publications
référencées est obligatoire pour une application correcte de la présente publication.
9) L’attention est attirée sur le fait que certains des éléments de la présente Publication de la CEI peuvent faire
l’objet de droits de propriété intellectuelle ou de droits analogues. La CEI ne saurait être tenue pour
responsable de ne pas avoir identifié de tels droits de propriété et de ne pas avoir signalé leur existence.
La tâche principale des comités d’études de la CEI est l’élaboration des Normes
internationales. Exceptionnellement, un comité d’études peut proposer la publication d’une
spécification technique
• lorsqu’en dépit de maints efforts, l’accord requis ne peut être réalisé en faveur de la
publication d’une Norme internationale, ou
• lorsque le sujet en question est encore en cours de développement technique ou quand,
pour une raison quelconque, la possibilité d’un accord pour la publication d’une Norme
internationale peut être envisagée pour l’avenir mais pas dans l’immédiat.

– 20 – TS 62271-304 © CEI:2008

Les spécifications techniques font l’objet d’un nouvel examen trois ans au plus tard après leur
publication afin de décider éventuellement de leur transformation en Normes internationales.

La CEI 62271-304, qui est une spécification technique, a été établie par le sous-comité 17C:
Ensembles d’appareillages à haute tension, du comité d’études 17 de la CEI: Appareillage.

Le texte de cette spécification technique est issu des documents suivants:

Projet d’enquête Rapport de vote

17C/402/DTS 17C/422A/RVC
Le rapport de vote indiqué dans le tableau ci-dessus donne toute information sur le vote ayant
abouti à l'approbation de cette spécification technique.
Cette première édition de la CEI/TS 62271-304 annule et remplace la première édition de la
CEI/TR 60932 parue en 1988 dont elle constitue une révision technique.
Le fondement des modifications de ce document révisé consiste en la prise en compte du
mode d’utilisation actuel de l’appareillage haute tension de moins de 52 kV
Cette publication a été rédigée selon les Directives ISO/CEI, Partie 2.
Une liste de toutes les parties de la série CEI 62271, présentée sous le titre général
Appareillage à haute tension, peut être consultée sur le site web de la CEI.
Le comité a décidé que le contenu de cette publication ne sera pas modifié ava
...