Electrical installation guide - Part 52: Selection and erection of electrical equipment - Wiring systems

IEC/TR 61200-52:2013 is Technical Report which serves as a supplement to IEC 60364-5-52:2009 and explains the rules so as to facilitate the design, selection, erection and maintenance of wiring systems. It follows the numbering of that standard. This technical report is written for everyone concerned with the design, the selection and supply of equipment, as well as the persons who install, maintain and use electrical installations. This second edition cancels and replaces the first edition, published in 1993, and constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
- guidance associated with conduit systems, cable ducting systems, cable trunking systems, cable tray systems and cable ladder systems has been added giving, for example, recommended maximum straight lengths of conduit to ease the installation circuit wiring;
- guidance associated with selection and erection of wiring systems in relation to external influences has been extended to cover impact, and other mechanical stresses;
- guidance for grouping of cables has been added; and
- guidance on maximum temperatures of terminals in normal service conditions has been extended.

Guide pour les installations électriques - Partie 52: Choix et mise en oeuvre des matériels électriques - Canalisations

La CEI/TR 61200-52:2013 est un Rapport Technique qui constitue un supplément à la CEI 60364-5-52:2009 et explique les règles de manière à faciliter la conception, le choix, la mise en oeuvre et la maintenance des canalisations. Sa numérotation des articles suit la numérotation de la CEI 60364-5-52. Il est rédigé à l'intention de toute personne concernée par la conception, le choix et la fourniture des matériels, ainsi qu'à l'intention des personnes qui installent, assurent la maintenance et utilisent des installations électriques. Cette deuxième édition annule et remplace la première édition, parue en 1993, et constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
- des recommandations concernant les systèmes de conduits, systèmes de conduits-profilés, systèmes de goulottes, systèmes de chemins de câbles et systèmes d'échelles à câbles ont été ajoutées pour donner, par exemple, les longueurs maximales recommandées pour les conduits afin de faciliter l'installation des circuits;
- les recommandations pour le choix et la mise en oeuvre des canalisations en tenant compte des influences externes ont été étendues aux impacts et autres contraintes mécaniques;
- des recommandations pour les groupements de câbles ont été ajoutées; et
- des recommandations sur les températures maximales des bornes en conditions de fonctionnement normal ont été étendues.

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Status
Published
Publication Date
09-Jul-2013
Current Stage
PPUB - Publication issued
Start Date
10-Jul-2013
Completion Date
10-Jul-2013
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IEC/TR 61200-52
Edition 2.0 2013-07
TECHNICAL
REPORT
RAPPORT
TECHNIQUE
Electrical installation guide –
Part 52: Selection and erection of electrical equipment – Wiring systems
Guide pour les installations électriques –
Partie 52: Choix et mise en œuvre des matériels électriques – Canalisations
IEC/TR 61200-52:2013
---------------------- Page: 1 ----------------------
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---------------------- Page: 2 ----------------------
IEC/TR 61200-52
Edition 2.0 2013-07
TECHNICAL
REPORT
RAPPORT
TECHNIQUE
Electrical installation guide –
Part 52: Selection and erection of electrical equipment – Wiring systems
Guide pour les installations électriques –
Partie 52: Choix et mise en œuvre des matériels électriques – Canalisations
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX M
ICS 29.060.01; 91.140.50 ISBN 978-2-8322-0882-3

Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale
---------------------- Page: 3 ----------------------
– 2 – TR 61200-52 © IEC:2013
CONTENTS

FOREWORD ........................................................................................................................... 3

520 Introduction ................................................................................................................. 5

520.1 Scope .............................................................................................................. 5

520.2 Normative references ....................................................................................... 5

521 Types of wiring system ................................................................................................ 6

521.6 Conduit systems, cable ducting systems, cable trunking systems, cable

tray systems and cable ladder systems ............................................................ 6

522 Selection and erection of wiring systems in relation to external influences ................... 7

522.4 Presence of solid foreign bodies ...................................................................... 7

522.6 Impact .............................................................................................................. 7

522.8 Other mechanical stresses ............................................................................... 7

522.8.101 Reduction of the risk of short-circuit or earth fault ........................ 7

522.11 Solar radiation and ultraviolet radiation ............................................................ 7

523 Current-carrying capacities .......................................................................................... 8

526 Electrical connections .................................................................................................. 8

526.4 Maximum temperatures of terminals in normal service conditions ..................... 8

526.4.101 General ....................................................................................... 8

526.4.201 Limitation of temperature at a terminal ......................................... 8

526.4.301 Limitation of the effects of temperature at a terminal in

normal service ............................................................................. 9

526.8 Connection of multiwire, fine wire and very fine wire conductors .................... 10

528 Proximity of wiring systems to other services ............................................................. 10

528.2 Proximity of communication cables................................................................. 10

Annex B, Current-carrying capacity ....................................................................................... 11

Annex I (informative) List of notes concerning certain countries ............................................ 12

Bibliography .......................................................................................................................... 13

Table 52A – Cable surrounded by thermal insulation ............................................................ 11

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TR 61200-52 © IEC:2013 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRICAL INSTALLATION GUIDE –
Part 52: Selection and erection of electrical equipment –
Wiring systems
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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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

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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. However, a

technical committee may propose the publication of a technical report when it has collected

data of a different kind from that which is normally published as an International Standard, for

example "state of the art".
IEC 61200-52, which is a technical report, has been prepared by IEC technical
committee 64: Electrical installations and protection against electric shock.

This second edition cancels and replaces the first edition, published in 1993, and constitutes

a technical revision.

This edition includes the following significant technical changes with respect to the previous

edition:
---------------------- Page: 5 ----------------------
– 4 – TR 61200-52 © IEC:2013

a) the scope has been modified; whilst the Guide does not form part of the IEC 60364 series,

it serves as a supplement to IEC 60364-5-52:2009 and explains the rules so as to facilitate

the design, selection, erection and maintenance of wiring systems;

b) guidance associated with conduit systems, cable ducting systems, cable trunking systems,

cable tray systems and cable ladder systems has been added giving, for example,

recommended maximum straight lengths of conduit to ease the installation circuit wiring;

c) guidance associated with selection and erection of wiring systems in relation to external

influences has been extended to cover impact, and other mechanical stresses.
d) guidance for grouping of cables has been added.

e) guidance on maximum temperatures of terminals in normal service conditions has been

extended;

f) guidance on the connection of multi wire, fine wire and very fine wire conductors has been

added;
g) guidance on proximity of communication cables has been added;
h) guidance on cables in contact with thermal insulation has been added.

This technical report serves as a supplement to IEC 60364-5-52:2009 and follows the

numbering of that standard.
The text of this technical report is based on the following documents:
Enquiry draft Report on voting
64/1875/DTR 64/1887/RVC

Full information on the voting for the approval of this technical report can be found in the

report on voting indicated in the above table.

This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

The committee has decided that the contents of this publication will remain unchanged until

the stability 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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TR 61200-52 © IEC:2013 – 5 –
ELECTRICAL INSTALLATION GUIDE –
Part 52: Selection and erection of electrical equipment –
Wiring systems
520 Introduction
520.1 Scope

This Technical Report serves as a supplement to IEC 60364-5-52:2009 and explains the rules

so as to facilitate the design, selection, erection and maintenance of wiring systems.

It is written for everyone concerned with the design, the selection and supply of equipment, as

well as the persons who install, maintain and use electrical installations.
520.2 Normative references

The following documents, in whole or in part, are normatively referenced in this document and

are indispensable for its application. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any
amendments) applies.

IEC 60227-4, Polyvinyl chloride insulated cables of rated voltages up to and including

450/750 V – Part 4: Sheathed cables for fixed wiring

IEC 60245-4, Rubber insulated cables – Rated voltages up to and including 450/750 V –

Part 4: Cords and flexible cables

IEC 60364-4-43:2008, Low-voltage electrical installations – Part 4-43 Protection for safety –

Protection against overcurrent

IEC 60364-5-51:2005, Electrical installations of buildings – Part 5-51: Selection and erection

of electrical equipment – Common rules

IEC 60364-5-52:2009, Low-voltage electrical installations – Part 5-52: Selection and erection

of electrical equipment – Wiring systems

IEC 60502-1, Power cables with extruded insulation and their accessories for rated voltages

from 1 kV (U = 1,2 kV) up to 30 kV (U = 36 kV) – Part 1: Cables for rated voltages of 1 kV

m m
(U = 1,2 kV) and 3 kV (U = 3,6 kV)
m m

IEC/TR 60890, A method of temperature-rise assessment by extrapolation for partially type-

tested assemblies (PTTA) of low-voltage switchgear and controlgear

IEC/TR 60943, Guidance concerning the permissible temperature rise for parts of electrical

equipment, in particular for terminals

IEC 61084 (all parts), Cable trunking and ducting systems for electrical installations

IEC 61084-2-2, Cable trunking and ducting systems for electrical installations – Part 2-2:

Particular requirements – Cable trunking systems and cable ducting systems intended for

underfloor and flushfloor installations
---------------------- Page: 7 ----------------------
– 6 – TR 61200-52 © IEC:2013
IEC 61386 (all parts), Conduit systems for cable management

IEC 61386-21, Conduit systems for cable management – Part 21: Particular requirements –

Rigid conduit systems

IEC 61386-22, Conduit systems for cable management – Part 22: Particular requirements –

Pliable conduit systems

IEC 61386-23, Conduit systems for cable management – Part 23: Particular requirements –

Flexible conduit systems
IEC 61439 (all parts), Low-voltage switchgear and controlgear assemblies
521 Types of wiring system
521.6 Conduit systems, cable ducting systems, cable trunking systems, cable tray
systems and cable ladder systems

The following includes recommendations to ease the installation, or replacement, of circuits

installed in conduit.

a) Straight conduit lengths between access points should not exceed 25 m. Conduit lengths

which include changes in direction should not exceed 15 m between access points. There

should be no more than three changes in direction between access points.
b) The number of bends in any run should be minimized.
c) Any bending radius should be as large as possible and in accordance with the
manufacturer's instructions.

d) The cables or insulated conductors should not occupy more than one-third of the total

internal cross-sectional area of the conduit.

e) Conduit systems should be installed so as to minimize the mechanical stress on the

conduit.

f) If conduit systems are to be installed outdoors, consideration should be given to the

ambient temperature and effects of solar radiation as indicated in 522.1 and 522.11.

g) Where self-recovering conduit has to be embedded in concrete, consideration should be

given to the possibility of permanent deformation of the cross-section of the conduit that

might result in damage to the enclosed cables or insulated conductors. Where necessary,

measures should be taken such as additional mechanical protection or the use of conduit

having suitably increased diameter or resistance to compression.

When electrical accessories are mounted in trunking or ducting systems that are installed in

or under a floor, the type of floor treatment likely to be used (wet or dry) should be taken into

consideration.

Where cable trunking systems are installed in a skirting position (e.g. Item 6 of Table A52.3 of

IEC 60364-5-52:2009), damage caused by the ingress of water can be avoided by placing the

insulated conductors laid within at least 10 mm above the floor level.

Cable trunking systems and cable ducting systems intended for underfloor and flushfloor

installations are covered by IEC 61084-2-2.

Where cable tray systems are used, the use of a cover can also be necessary, for example for

mechanical protection or design reasons or preventing access (e.g. in the basin of public

fountains).
---------------------- Page: 8 ----------------------
TR 61200-52 © IEC:2013 – 7 –
522 Selection and erection of wiring systems in relation to external
influences
522.4 Presence of solid foreign bodies (AE)

Cable management systems will not protect against ingress of solid foreign bodies unless they

comply with a protection degree at least IP2X.
522.6 Impact

Trunking, ducting and conduit systems provide mechanical protection to the cable, but cable

tray and cable tray with cover might not provide such mechanical protection, as, according to

the product standard, they are not tested for this purpose.
522.8 Other mechanical stresses (AJ)
522.8.101 Reduction of the risk of short-circuit or earth fault

Where devices for short-circuit protection are placed in accordance with 434.2.1 of

IEC 60364-4-43:2008, it is required that the conductors shall be installed so as to reduce the

risk of a short-circuit to a minimum.

This implies that conductor arrangements should be made so as to minimize the risk of

contact between the conductors and contact of live conductors with earthed parts and to

provide protection against damage due to external influences (e.g. mechanical damage).

Examples of such arrangements are as follows:

a) Arrangement consisting of single-core cables in accordance with IEC 60502-1, single-core

non-metallic sheathed cables in accordance with IEC 60227-4 or single-core rubber

insulated and sheathed flexible cables in accordance with IEC 60245-4 and where the risk

of mechanical damage is prevented.

b) Cables and rubber-insulated and sheathed flexible cables laid so that they are accessible

but not in the vicinity of combustible materials and where the risk of mechanical damage is

prevented.

c) Cables with non-metallic sheath installed in rigid, flexible or pliable conduits in accordance

with IEC 61386-21, IEC 61386-22 or IEC 61386-23.

d) Cables with non-metallic sheath installed in trunking or ducting systems in accordance

with the IEC 61084 series.

With regard to safety, an arrangement of cables or insulated conductors which could burn out

without endangering their environment (e.g. buried cables) is considered to be equivalent to a

circuit installed so as to reduce the risk of a short-circuit to a minimum.
522.11 Solar radiation (AN) and ultraviolet radiation

Where wiring systems are installed outdoors, particular attention should be given to the

effects of solar radiation. The two main effects to be considered are the heating effects and

the UV stability. As indicated in 512.2.2 of IEC 60364-5-51:2005 and Table 51A of that

standard, if the product does not, by its construction, have the characteristics relevant to the

external influences of its location, it may nevertheless be used on condition that it is provided

with appropriate additional protection in the erection of the installation, such as interposition

of screens.

NOTE The IEC 60287 [1] series gives a method for determining the current-carrying capacity in case of solar

radiation.
Figures in square brackets refer to the Bibliography.
---------------------- Page: 9 ----------------------
– 8 – TR 61200-52 © IEC:2013
523 Current-carrying capacities

The current-carrying capacity of a cable is affected by the type of insulation material of the

cable, ambient temperature, installation method, grouping and presence of thermal insulation.

See the NOTE in 522.11.

Annex B of IEC 60364-52:2009 includes tabulated reduction factors for a limited number of

circuits. Increasing the number of circuits in a group (conductors within a single installation

method) will require further reduction in the current-carrying capacity of those conductors

(smaller reduction factors than specified for the maximum number of circuits or conductors),

due to increased heating effects. Because of this, it is recommended that such groups, with

more circuits or conductors than the maximum indicated in the tables, be divided into smaller

groups of circuits or conductors with spacing provided between the groups.
526 Electrical connections
526.4 Maximum temperatures of terminals in normal service conditions
526.4.101 General

The temperature of a terminal is the sum of the ambient temperature and its temperature rise

in normal service.

Product standards give conventional limit values for temperature rise under defined test

conditions. For installation conditions that differ from the defined test conditions, rating factors

may need to be applied and guidance should be obtained from the manufacturer. Relevant

standards in this respect are the IEC 61439 series and IEC 60890.

The temperature at a terminal is affected by the heat dissipated in normal service by the

equipment. This heat may be caused by internal losses dissipated in the equipment and by

neighbouring internal and external heat sources, if any. A possible external heat source is the

cable of the wiring system connected to the terminal equipment.

Compatibility between the temperature achieved at the terminals of equipment and the

temperature permitted for the insulation of the conductors and cables should be obtained by

appropriate arrangement during design/installation.
Current-carrying capacities of conductors, the values of which are tabulated in

IEC 60364-5-52, are calculated so that the temperature on the cores does not exceed the

permissible temperature determined by the selection of the insulation. These current-carrying

capacities do not take account of any temperature rise at a termination.
526.4.201 Limitation of temperature at a terminal

It is necessary to limit the temperature at a terminal so that the maximum steady-state or

peak temperature limits of the insulation of the conductors connected to the terminal and of

any insulating material used to support the connection are not exceeded. The temperature at

a terminal can be limited by one or more of the following measures:

a) Limitation of contents of enclosures (cubicles, cabinets, trunkings, conduits). The

limitation of contents of trunkings and conduits is recommended when a large number of

circuits issue from the same panel; in this case it is preferable to divide the circuits

between several runs of trunking or conduit.

b) Spacing between equipment in order to improve natural ventilation. Spacing between

adjacent equipment permits better dissipation of heat. It is necessary to refer to the

manufacturer's instructions. This solution is especially recommended when a great

number of items of equipment are installed in the same enclosure (cubicle or cabinet).

---------------------- Page: 10 ----------------------
TR 61200-52 © IEC:2013 – 9 –

c) Appropriate arrangement of equipment dissipating heat inside enclosures. It is

recommended that equipment dissipating heat is installed in an appropriate way so that

the correct operation of other equipment will not be impaired. Other means, such as the

interposition of screens or deflectors, may be used for this purpose.

d) Natural or forced ventilation or air-conditioning of cubicles, cabinets or locations. Forced

ventilation of the equipment may be necessary, for reasons other than cooling, in specific

applications, for example to protect against ingress of dust.

e) Derating of equipment by use of equipment having higher rated current, consequently

dissipating less heat. Derating of equipment can be used to reduce the temperature of

terminals, provided that such derating is permitted for the equipment.

f) Selection of material for enclosures of cubicles or cabinets in which terminals are installed

in order to improve the thermal dissipation. Thin metallic enclosures will dissipate heat

more readily than thick walled enclosures manufactured from insulation materials.

g) Maintenance of correct clamping of conductors in the terminals. Arrangements should be

made to ensure the maintenance of clamping pressure of conductors in their terminals.

Such arrangements may be built in (for example, use of resilient connections) or result

from instructions for the inspection of the installation.

h) Introduction of an intermediate terminal (of the appropriate rated operating temperature)

outside the current-using equipment enables a conductor of larger cross-sectional area or

a higher temperature type of cable to be connected.

i) Where cables that are permitted to run at a temperature exceeding 70 °C (such as cross-

linked insulated cables) are connected to equipment or accessories designed to operate

at a temperature not exceeding 70 °C, the conductor size should be chosen based on the

current ratings for 70 °C cables of a similar construction.

j) Separation of conductors of multicore cables between the end of the sheath and the

terminal will lead to a decrease in the terminal temperature. Choice of a sufficient length

for the separation may be based on experiment or on a calculation according to
IEC/TR 60943.

k) Connection of a short length of conductor, at the termination, whose cross-sectional area

is larger than that required by the current, will reduce the temperature at the termination.

Increasing the cross-sectional area of conductors for other reasons (voltage drop,

withstand of short-circuit currents, reduction of the fault loop impedance) improves the

thermal withstand of the conductors and hence reduces the possibility of excessive

temperatures at terminations.

526.4.301 Limitation of the effects of temperature at a terminal in normal service

The effect of temperature rise of terminals can be limited by one or more of the following:

a) Selection of the in
...

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