SIST EN 60439-5:2007
(Main)Low-voltage switchgear and controlgear assemblies -- Part 5: Particular requirements for assemblies for power distribution in public networks
Low-voltage switchgear and controlgear assemblies -- Part 5: Particular requirements for assemblies for power distribution in public networks
Substation cable distribution boards (SCDBs) and cable distribution cabinets (CDCs) for power distribution in networks shall comply with all the requi rements of IEC 60439-1 (1999) if not otherwise indicated hereinafter and shall also comply with the particular requirements contained in this publication. This standard gives supplementary requirements for substation cable distribution boards (SCDBs) and cable distribution cabinets (CDCs), which are stationary, type-tested assemblies (TTA). They are used for the distribution of electrical energy in three-phase systems. Opentype ASSEMBLY are not covered by this standard. Individual components, such as fuses and switching devices that comply with other standards, shall also comply with the supplementary requirements of this standard. The object of this standard is to state the definitions and to specify the service conditions, construction requirements, technical characteristics and tests for SCDBs and CDCs. Higher performance and test levels may be required for particular networks, for example, those with meshed connections.
Niederspannungs-Schaltgerätekombinationen - Teil 5: Besondere Anforderungen für Schaltgerätekombinationen in Energieverteilungsnetzen
Ensembles d'appareillage à basse tension -- Partie 5: Règles particulières pour les ensembles pour réseaux de distribution publics
Cette norme fournit les exigences complémentaires pour les tableaux de distribution par câbles pour poste (SCDB) et les ensembles d'appareillage pour réseaux de distribution (ERD), qui sont des ENSEMBLES de série (ES) fixes. Ils sont utilisés pour la distribution de l'énergie électrique dans des systèmes triphasés. Les ENSEMBLES ouverts ne sont pas couverts par cette norme.
Sestavi nizkonapetostnih stikalnih naprav – 5. del: Posebne zahteve za sestave, predvidene za javna elektroenergetska razdelilna omrežja (IEC 60439-5:2006)
General Information
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EUROPEAN STANDARD
EN 60439-5
NORME EUROPÉENNE
October 2006
EUROPÄISCHE NORM
ICS 29.130.20; 29.240.99 Supersedes EN 60439-5:1996 + A1:1998 and EN 50300:2004
English version
Low-voltage switchgear and controlgear assemblies
Part 5: Particular requirements for assemblies
for power distribution in public networks
(IEC 60439-5:2006)
Ensembles d'appareillage Niederspannungs-
à basse tension Schaltgerätekombinationen
Partie 5: Règles particulières Teil 5: Besondere Anforderungen
pour les ensembles pour réseaux für Schaltgerätekombinationen
de distribution publics in Energieverteilungsnetzen
(CEI 60439-5:2006) (IEC 60439-5:2006)
This European Standard was approved by CENELEC on 2006-09-01. CENELEC members are bound to comply
with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard
the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and notified
to the Central Secretariat has the same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus, the Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels
© 2006 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 60439-5:2006 E
---------------------- Page: 2 ----------------------
EN 60439-5:2006 - 2 -
Foreword
The text of document 17D/334/FDIS, future edition 2 of IEC 60439-5, prepared by SC 17D, Low-voltage
switchgear and controlgear assemblies, of IEC TC 17, Switchgear and controlgear, was submitted to the
IEC-CENELEC parallel vote and was approved by CENELEC as EN 60439-5 on 2006-09-01.
This European Standard supersedes EN 60439-5:1996 + A1:1998 and EN 50300:2004.
The main change with respect to EN 60439-5:1996 is the inclusion of substation cable distribution boards
(SCDBs). The title has therefore been amended.
In view of the fact that this publication should be read in conjunction with EN 60439-1:1999, the
numbering of its clauses and subclauses correspond with the latter. The clauses of this standard
supplement, modify or replace clauses in EN 60439-1.
Where there is no corresponding clause or subclause in this standard, the clause or subclause of the
main document applies without modification.
Clauses, subclauses, figures and tables which are additional to those in Part 1 are numbered starting
from 101.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2007-06-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2009-09-01
Annexes ZA and ZB have been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 60439-5:2006 was approved by CENELEC as a European
Standard without any modification.
__________
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- 3 - EN 60439-5:2006
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
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.
NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.
Publication Year Title EN/HD Year
IEC 60068-2-11 1981 Environmental testing EN 60068-2-11 1999
Part 2: Tests - Test Ka: Salt mist
IEC 60068-2-30 2005 Environmental testing EN 60068-2-30 2005
Part 2-30: Tests - Test Db: Damp heat, cyclic
(12 h + 12 h cycle)
IEC 60238 2004 Edison screw lampholders EN 60238 2004
+ corr. January 2005
IEC 60269-1 1998 Low-voltage fuses EN 60269-1 1998
Part 1: General requirements
IEC 60439-1 1999 Low-voltage switchgear and controlgear EN 60439-1 1999
A1 2004 assemblies A1 2004
Part 1: Type-tested and partially type-tested
assemblies
IEC 60446 1999 Basic and safety principles for man-machine EN 60446 1999
interface, marking and identification -
Identification of conductors by colours or
numerals
IEC 60529 1989 Degrees of protection provided by enclosures EN 60529 1991
(IP Code) + corr. May 1993
A1 1999 A1 2000
IEC 60695-11-10 1999 Fire hazard testing EN 60695-11-10 1999
Part 11-10: Test flames - 50 W horizontal and
vertical flame test methods
ISO 3231 1993 Paints and varnishes - Determination of EN ISO 3231 1997
resistance to humid atmospheres containing
sulphur dioxide
ISO 4628-3 2003 Paints and varnishes - Evaluation of EN ISO 4628-3 2003
degradation of coatings - Designation of
quantity and size of defects, and of intensity
of uniform changes in appearance
Part 3: Assessment of degree of rusting
ISO 4892-2 1994 Plastics - Methods of exposure to laboratory EN ISO 4892-2 1999
light sources
Part 2: Xenon arc sources
ISO 6506-1 2005 Metallic materials - Brinell hardness test EN ISO 6506-1 2005
Part 1: Test method
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EN 60439-5:2006 - 4 -
Publication Year Title EN/HD Year
ISO 9223 1992 Corrosion of metals and alloys - Corrosivity of - -
atmosphere - Classification
---------------------- Page: 5 ----------------------
- 5 - EN 60439-5:2006
Annex ZB
(informative)
A-deviations
A-deviation: National deviation due to regulations, the alteration of which is for the time being outside the
competence of the CENELEC member.
This European Standard falls under Directive 73/23/EEC
NOTE (from CEN/CENELEC IR Part 2:2002 , 2.17) Where standards fall under EC Directives, it is the view of the Commission of
the European Communities (OJ No C 59, 1982-03-09) that the effect of the decision of the Court of Justice in case 815/79
Cremonini/Vrankovich (European Court Reports 1980, p. 3583) is that compliance with A-deviations is no longer mandatory and that
the free movement of products complying with such a standard should not be restricted except under the safeguard procedure
provided for in the relevant Directive.
A-deviations in an EFTA-country are valid instead of the relevant provisions of the European Standard in
that country until they have been removed.
Clause Deviation
2.1.102 Spain
(Royal Decree 842/2002 (Reglamento Electrotécnico de Baja Tensión), Article 14)
The configuration of some parts of the electrical installations, including the assemblies for
public distribution cables, are under the responsibility of the utilities.
Furthermore, the requirements may be different for each region in Spain and be regulated by
regional legislation.
__________
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NORME CEI
INTERNATIONALE
IEC
60439-5
INTERNATIONAL
Deuxième édition
STANDARD
Second edition
2006-06
Ensembles d'appareillage à basse tension –
Partie 5:
Règles particulières pour les ensembles
pour réseaux de distribution publics
Low-voltage switchgear and
controlgear assemblies –
Part 5:
Particular requirements for assemblies
for power distribution in public networks
IEC 2006 Droits de reproduction réservés Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in any
utilisée sous quelque forme que ce soit et par aucun procédé, form or by any means, electronic or mechanical, including
électronique ou mécanique, y compris la photocopie et les photocopying and microfilm, without permission in writing from
microfilms, sans l'accord écrit de l'éditeur. the publisher.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch Web: www.iec.ch
CODE PRIX
U
PRICE CODE
Commission Electrotechnique Internationale
International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
Pour prix, voir catalogue en vigueur
For price, see current catalogue
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60439-5 IEC:2006 – 3 –
CONTENTS
FOREWORD.5
1 General .9
2 Definitions .11
3 Classification of ASSEMBLIES .15
4 Electrical characteristics of ASSEMBLIES .17
5 Information to be given regarding the ASSEMBLY .17
6 Service conditions .17
7 Design and construction .19
8 Test specifications.25
Annex A (normative) Minimum and maximum cross-section of copper and aluminium
conductors, suitable for connection.57
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60439-5 IEC:2006 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR ASSEMBLIES –
Part 5: Particular requirements for assemblies
for power distribution in public networks
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
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
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
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
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.
International Standard IEC 60439-5 has been prepared by subcommittee 17D: Low-voltage
switchgear and controlgear assemblies, of IEC technical committee 17: Switchgear and
controlgear.
This second edition cancels and replaces the first edition (1996) and its amendment 1 (1998).
It constitutes a technical revision due to the inclusion of substation cable distribution boards
(SCDBs). The title has therefore been amended.
The text of this standard is based on the following documents:
FDIS Report on voting
17D/334/FDIS 17D/335/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
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60439-5 IEC:2006 – 7 –
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
In view of the fact that this publication should be read in conjunction with IEC 60439-1 (1999),
the numbering of its clauses and subclauses correspond with the latter. The clauses of this
standard supplement, modify or replace clauses in IEC 60439-1.
Where there is no corresponding clause or subclause in this standard, the clause or
subclause of the main document applies without modification.
Clauses, subclauses, figures and tables which are additional to those in Part 1 are numbered
starting from 101.
The IEC 60439 series contains the following parts, under the general title Low-voltage
switchgear and controlgear assemblies:
Part 1: Type-tested and partially type-tested assemblies
Part 2: Particular requirements for busbar trunking systems (busways)
Part 3: Particular requirements for low-voltage switchgear and controlgear assemblies
intended to be installed in places where unskilled persons have access for their use
– Distribution boards
Part 4: Particular requirements for assemblies for construction sites (ACS)
Part 5: Particular requirements for assemblies for power distribution in public networks
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
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
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60439-5 IEC:2006 – 9 –
LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR ASSEMBLIES –
Part 5: Particular requirements for assemblies
for power distribution in public networks
1 General
1.1 Scope and object
Replacement:
Substation cable distribution boards (SCDBs) and cable distribution cabinets (CDCs) for
power distribution in networks shall comply with all the requirements of IEC 60439-1 (1999) if
not otherwise indicated hereinafter and shall also comply with the particular requirements
contained in this publication.
This standard gives supplementary requirements for substation cable distribution boards
(SCDBs) and cable distribution cabinets (CDCs), which are stationary, type-tested assemblies
(TTA). They are used for the distribution of electrical energy in three-phase systems. Open-
type ASSEMBLY are not covered by this standard.
Individual components, such as fuses and switching devices that comply with other standards,
shall also comply with the supplementary requirements of this standard.
The object of this standard is to state the definitions and to specify the service conditions,
construction requirements, technical characteristics and tests for SCDBs and CDCs. Higher
performance and test levels may be required for particular networks, for example, those with
meshed connections.
NOTE 1 If a CDC is equipped with additional equipment (for example meters), in such a way that the main
function is changed considerably, then other standards may also apply as agreed between user and manufacturer
(see 7.6).
NOTE 2 Where local regulations and practices permit, an SCDB or CDC according to this standard may be used
in other than public networks.
SCDBs are suitable for installation in places where only skilled persons have access for their
use; however, outdoor types may be installed in situations which may be accessible to the
public.
SCDBs are connected to the low voltage terminals of distribution transformers by means of
connecting bars, rods or cables.
CDCs are for outdoor installation in places which are accessible to the public, and where only
skilled persons have access for their use.
1.2 Normative references
This subclause of Part 1 applies with the following additions:
IEC 60068-2-11:1981, Environmental testing – Part 2: Tests – Test Ka: Salt mist
---------------------- Page: 11 ----------------------
60439-5 IEC:2006 – 11 –
IEC 60068-2-30:2005, Environmental testing – Part 2-30: Tests – Test Db: Damp heat, cyclic
(12+12-hour cycle)
IEC 60238:2004, Edison screw lampholders
IEC 60269-1:1998, Low-voltage fuses – Part 1: General requirements
IEC 60439-1:1999, Low-voltage switchgear and controlgear assemblies – Part 1: Type-tested
and partially type-tested assemblies
Amendment 1 (2004)
IEC 60446:1999, Basic and safety principles for man-machine interface, marking and
identification – Identification of conductors by colours or numerals
IEC 60529:2001, Degrees of protection provided by enclosures (IP code)
IEC 60695-11-10:1999, Fire hazard testing – Part 11-10: Test flames – 50 W horizontal and
vertical flame test methods
ISO 3231:1993, Paints and varnishes – Determination of resistance to humid atmospheres
containing sulphur dioxide
ISO 4628-3:2003, Paints and varnishes – Evaluation of degradation of coatings – Designation
of quantity and size of defects, and of intensity of uniform changes in appearance – Part 3:
Designation of degree of rusting
ISO 4892-2:1994, Plastics – Methods of exposure to laboratory light sources – Part 2: Xenon-
arc sources
ISO 6506-1:2005, Metallic materials – Brinell hardness test – Part 1: Test method
ISO 9223:1992, Corrosion of metals and alloys – Corrosivity of atmosphere – Classification
2 Definitions
The definitions of Part 1 apply with the following additions and modifications:
2.1.1.2
partially type-tested low-voltage switchgear and controlgear assembly
PTTA
Not applicable.
2.1.101
cable distribution cabinet
CDC
cubicle-type ASSEMBLY for outdoor installation which in use receives electrical energy via
cables from one or more substation cable distribution boards (SCDBs), and distributes that
energy through one or more cables to other equipment
NOTE This other equipment is not intended to consume electrical energy (see Figure 101).
2.1.101.1
ground-mounted cable distribution cabinet
cable distribution cabinet for installation at ground level on a foundation
NOTE The cabinet entries for external conductors are suitable for cables.
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60439-5 IEC:2006 – 13 –
2.1.101.2
pole-mounted cable distribution cabinet
cable distribution cabinet for installation on a pole, on which a transformer is normally
mounted, in an aerial network
NOTE The cabinet entries for external conductors are suitable for cables or insulated overhead line conductors.
2.1.101.3
wall-mounted surface type cable distribution cabinet
cable distribution cabinet for installation on the surface of a wall
NOTE The cabinet entries for external conductors are suitable for cable.
2.1.101.4
wall-mounted recessed type cable distribution cabinet
cable distribution cabinet for installation into a recess in a wall
NOTE 1 A CDC is not designed to support the portion of the wall above the CDC.
NOTE 2 The cabinet entries for external conductors are suitable for cables.
2.1.102
substation cable distribution board
SCDB
an ASSEMBLY for direct connection to one or more distribution transformers, incorporating one
or more incoming circuits (disconnector, switch disconnector, circuit breaker, etc.) that are
connected via busbars to one or more outgoing functional units (fuse disconnectors, fuse
switch disconnectors, circuit breakers, etc.) so as to provide protection for, and a means of
isolating and controlling, the outgoing circuits.
NOTE An SCDB is installed, operated and maintained solely by skilled persons.
2.1.102.1
SCDB – indoor
SCDB-I
substation cable distribution board (SCDB) for installation indoors, including all structural
parts necessary to support busbars, functional units and other ancillary devices, necessary to
complete the ASSEMBLY
2.1.102.2
SCDB – outdoor cable connected
SCDB-CCO
cubicle type substation cable distribution board (SCDB) for outdoor installation which is
independently mounted and connected to the distribution transformer by means of cables
2.1.102.2.1
SCDB-CCO – ground mounted
SCDB-CCO suitable for outdoor installation at or slightly above ground level in a situation
which may be accessible to the public
2.1.102.2.2
SCDB-CCO – pole mounted
SCDB-CCO suitable for outdoor installation above ground level on a pole
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60439-5 IEC:2006 – 15 –
2.1.102.3
SCDB – outdoor transformer mounted
SCDB-TMO
cubicle type substation cable distribution board (SCDB) for outdoor installation, which is
suitable for fixing to the low voltage flange of a distribution transformer
2.1.102.3.1
SCDB-TMO – ground mounted
SCDB-TMO which is suitable for fixing to the low voltage flange of a ground mounted
distribution transformer
2.1.102.3.2
SCDB-TMO – pole mounted
SCDB-TMO which is suitable for fixing to the low voltage flange of a pole mounted distribution
transformer
2.2
constructional units of ASSEMBLIES
2.2.1
section
Not applicable.
2.2.2
sub-section
Not applicable.
2.3
External design of ASSEMBLIES
2.3.1
Open-type ASSEMBLY
Not applicable.
2.3.3.3
desk-type ASSEMBLY
Not applicable.
2.3.4
busbar trunking system
busway
Not applicable.
2.5
conditions of installation of ASSEMBLIES
2.5.4
movable ASSEMBLY
Not applicable
3 Classification of ASSEMBLIES
The third dash is not applicable.
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60439-5 IEC:2006 – 17 –
4 Electrical characteristics of ASSEMBLIES
4.101 Rated current (of SCDB or CDC)
The rated current of an SCDB or CDC is that stated by the manufacturer as the rated current
of the incoming circuit. If there is more than one incoming circuit, the rated current of that
SCDB or CDC is either the arithmetic sum of the rated currents of all incoming circuits that
are intended to be used simultaneously or the rated current of the main phase busbars,
whichever is the lower value. This current shall be carried without the temperature rise of the
individuals part exceeding the limits specified in 7.3 when tested according to 8.2.1.
5 Information to be given regarding the ASSEMBLY
5.1 Nameplates
r) Not applicable
Addition:
u) rated current of an ASSEMBLY as defined in 4.101 .
Nameplates may be placed inside enclosures of the ASSEMBLY provided their intended place
ensures good legibility and visibility when the door is open or the cover is removed.
NOTE Further information may be included by agreement between the user and the manufacturer.
5.2 Markings
Add at the end of the subclause:
It shall be possible to identify each functional unit in a clearly visible manner.
In the case of removable fuse-carriers which are specific to a fuseway, a label shall be placed
on the fuse-carrier as well as on the fuse base, to avoid incorrect interchanging of the fuse-
carrier.
6 Service conditions
6.2.8 Addition:
NOTE Exposure to traffic vibration is a normal service condition for ground mounted SCDBs and CDCs.
6.2.9 Installation in such a manner that the current-carrying capacity or breaking
capacity is affected
Addition:
NOTE Recessing into a wall is not considered to be a special condition for a CDC.
6.2.101 Exposure to heavy snowfall and snowdrift
For installations in regions where heavy snowfalls and snowdrift occur, which necessitate
snow clearance by ploughing, subject to agreement between manufacturer and user, an arctic
climate can be considered a normal condition; however, the lower temperature limit of -25°C
may be applied (see 8.2.101.2.2).
---------------------- Page: 15 ----------------------
60439-5 IEC:2006 – 19 –
7 Design and construction
7.1.1 General
Replace the second sentence of the first paragraph:
The insulating materials used for enclosures, barriers and other insulating parts shall have a
resistance to thermal stress and flame retardant properties in accordance with 8.2.102.
Add at the end of the second paragraph:
The materials of coatings shall be subject to agreement between user and manufacturer and
shall be sufficient to pass the appropriate tests of 8.2.103.
Add at the end of the third paragraph:
The mechanical properties of a SCDB-CCO, SCDB-TMO and CDC shall comply with 8.2.101.
Parts of the SCDB-CCO and CDC intended to be embedded in the ground shall withstand the
stresses imposed on them during installation and normal service (see 8.2.101.6).
Add the following paragraphs at the end of the subclause:
Except in the case of an ASSEMBLY providing protection by total insulation, the frame or
enclosure of the ASSEMBLY shall incorporate a suitable earth terminal of an appropriate size to
provide a connection for an external protective conductor.
For an ASSEMBLY which is expected to feed overhead cable lines, outgoing units shall be
designed in such a way that an attached cable(s) can be earthed at the termination(s).
7.1.1.101 Marking of CDC as an obstacle to snow clearance
Where a ground mounted CDC is suitable for use in an arctic climate in accordance with
6.1.1.2 or alternatively, if required by the user, it shall be possible to mark it as an obstacle to
snow clearance. Holders shall be provided, attached to the CDC, to accommodate marking
rods and it shall be possible to install and make adjustments to the position of the marking rod
from outside the CDC. The holders shall be constructed in a manner which ensures that the
holder or marking rod will give way to a mechanical force before the transmitted force to the
CDC enclosure reaches the value which would adversely affect the degree of protections (IP
code).
7.1.1.102 Ease of operation and maintenance
All parts of the ASSEMBLY shall, as far as practicable, be readily accessible and replaceable
without excessive dismantling. The conditions for interchangeability of parts of the ASSEMBLY
may be subject to an agreement between the user and the manufacturer.
The design shall be such that the cables can be readily connected from the front.
When an SCDB does not have a means of measurement incorporated, it shall be possible, by
the use of a portable instrument, to readily and safely measure voltages in all phases of
incoming units and on both sides of all current breaking and/or switch devices of outgoing
units, also the current in one phase of all outgoing units. During this operation all live parts of
---------------------- Page: 16 ----------------------
60439-5 IEC:2006 – 21 –
the SCDB shall be protected sufficiently to retain the required degree of protection in
accordance with 7.2.1.5. Instructions concerni
...
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