IEC 60364-5-54:2011

Low-voltage electrical installations - Part 5-54: Selection and erection of electrical equipment - Earthing arrangements and protective conductors

IEC 60364-5-54:2011 addresses the earthing arrangements and protective conductors including protective bonding conductors in order to satisfy the safety of the electrical installation. This third edition cancels and replaces the second edition, published in 2002, and constitutes a technical revision. The main changes with respect to the previous edition are listed below:
- clarification of the definition of protective conductor;
- improved specification of mechanical characteristics of the earth electrode;
- introduction of earth electrode for protection against electric shock and lighting protection;
- annexes describing concrete-embedded foundation earth electrodes and soil-embedded earth electrode.

Installations électriques basse-tension - Partie 5-54: Choix et mise en oeuvre des matériels électriques - Installations de mise à la terre et conducteurs de protection

La CEI 60364-5-54:2011 concerne les installations de mise à la terre et les conducteurs de protection, y compris les conducteurs de liaison de protection afin de satisfaire à la sécurité de l'installation électrique. Cette troisième édition annule et remplace la deuxième édition, parue en 2002, et constitue une révision technique. Les principales modifications par rapport à l'édition précédente sont les suivantes:
- la définition de conducteur de protection a été clarifiée;
- les caractéristiques mécaniques et physiques de la prise de terre ont été mieux spécifiées;
- introduction d'une prise de terre pour la protection contre les chocs électriques et la protection foudre;
- annexes qui décrivent les prises de terre à fond de fouille noyées dans le béton et les prises de terre noyées dans le sol.

Nizkonapetostne električne inštalacije - 5-54. del: Izbira in namestitev električne opreme - Ozemljitve, zaščitni vodniki in vodniki za zaščitno izenačitev potencialov

General Information

• Status: Published
• Publication Date: 22-Mar-2011
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 29.020 - Electrical engineering in general
• ICS: 91.140.50 - Electricity supply systems
• Technical Committee: TC 64 - Electrical installations and protection against electric shock
• Current Stage: PPUB - Publication issued
• Start Date: 23-Mar-2011
• Completion Date: 23-Mar-2011
• Ref Project: dSIST IEC 60364-5-54:2010 - Low-voltage electrical installations - Part 5-54: Selection and erection of electrical equipment - Earthing arrangements, protective conductors and protective bonding conductors

Standards Content (Sample)

IEC 60364-5-54
Edition 3.0 2011-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
BASIC SAFETY PUBLICATION
PUBLICATION FONDAMENTALE DE SÉCURITÉ
Low-voltage electrical installations –
Part 5-54: Selection and erection of electrical equipment – Earthing
arrangements and protective conductors
Installations électriques basse-tension –
Partie 5-54: Choix et mise en œuvre des matériels électriques – Installations de
mise à la terre et conducteurs de protection
IEC 60364-5-54:2011
---------------------- Page: 1 ----------------------
THIS PUBLICATION IS COPYRIGHT PROTECTED
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---------------------- Page: 2 ----------------------
IEC 60364-5-54
Edition 3.0 2011-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
BASIC SAFETY PUBLICATION
PUBLICATION FONDAMENTALE DE SÉCURITÉ
Low-voltage electrical installations –
Part 5-54: Selection and erection of electrical equipment – Earthing
arrangements and protective conductors
Installations électriques basse-tension –
Partie 5-54: Choix et mise en œuvre des matériels électriques – Installations de
mise à la terre et conducteurs de protection
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX X
ICS 29.020; 91.140.50 ISBN 978-2-88912-400-8
® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale
---------------------- Page: 3 ----------------------
– 2 – 60364-5-54  IEC:2011
CONTENTS

FOREWORD ........................................................................................................................... 4

INTRODUCTION ..................................................................................................................... 6

541 General ......................................................................................................................... 7

541.1 Scope ................................................................................................................. 7

541.2 Normative references ......................................................................................... 7

541.3 Terms and definitions ......................................................................................... 8

542 Earthing arrangements .................................................................................................. 9

542.1 General requirements ......................................................................................... 9

542.2 Earth electrodes ............................................................................................... 10

542.3 Earthing conductors ......................................................................................... 12

542.4 Main earthing terminal ...................................................................................... 13

543 Protective conductors .................................................................................................. 13

543.1 Minimum cross-sectional areas ........................................................................ 13

543.2 Types of protective conductors ......................................................................... 15

543.3 Electrical continuity of protective conductors .................................................... 16

543.4 PEN, PEL or PEM conductors .......................................................................... 16

543.5 Combined protective and functional earthing conductors .................................. 18

543.6 Currents in protective earthing conductors ....................................................... 19

543.7 Reinforced protective earthing conductors for protective earthing

conductor currents exceeding 10mA ................................................................. 19

543.8 Arrangement of protective conductors .............................................................. 19

544 Protective bonding conductors ..................................................................................... 19

544.1 Protective bonding conductors for connection to the main earthing

terminal ............................................................................................................ 19

544.2 Protective bonding conductors for supplementary bonding ............................... 20

Annex A (normative) Method for deriving the factor k in 543.1.2 (see also IEC 60724

and IEC 60949) ..................................................................................................................... 21

Annex B (informative) Example of earthing arrangements and protective conductors ........... 25

Annex C (informative) Erection of concrete-embedded foundation earth electrodes ............. 27

Annex D (informative) Erection of soil-embedded earth electrodes ....................................... 30

Annex E (informative) List of notes concerning certain countries .......................................... 34

Bibliography .......................................................................................................................... 40

Figure 54.1 – Examples of a PEN conductor connection ....................................................... 18

Figure B.54.1 – Examples of earthing arrangements for foundation earth electrode,

protective conductors and protective bonding conductors ..................................................... 26

Table 54.1 – Minimum size of commonly used earth electrodes, embedded in soil or

concrete used to prevent corrosion and provide mechanical strength .................................... 11

Table 54.2 – Minimum cross-sectional area of protective conductors (where not

calculated in accordance with 543.1.2) ................................................................................. 14

Table A.54.1 – Value of parameters for different materials .................................................... 21

Table A.54.2 – Values of k for insulated protective conductors not incorporated in

cables and not bunched with other cables ............................................................................. 22

Table A.54.3 – Values of k for bare protective conductors in contact with cable

covering but not bunched with other cables .......................................................................... 22

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60364-5-54  IEC:2011 – 3 –

Table A.54.4 – Values of k for protective conductors as a core incorporated in a cable

or bunched with other cables or insulated conductors ........................................................... 23

Table A.54.5 – Values of k for protective conductors as a metallic layer of a cable, e.g.

armour, metallic sheath, concentric conductor, etc. ............................................................... 24

Table A.54.6 – Values of k for bare conductors where there is no risk of damage to any

neighbouring material by the temperature indicated .............................................................. 24

Table D.54.1 – Resistivity for types of soil ............................................................................ 31

Table D.54.2 – Variation of the resistivity for different types of soil ....................................... 31

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– 4 – 60364-5-54  IEC:2011
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
LOW-VOLTAGE ELECTRICAL INSTALLATIONS –
Part 5-54: Selection and erection of electrical equipment –
Earthing arrangements and protective conductors
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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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 60364-5-54 has been prepared by IEC technical committee

64: Electrical installations and protection against electric shock.

This third edition cancels and replaces the second edition, published in 2002, and constitutes

a technical revision.
The main changes with respect to the previous edition are listed below:
– clarification of the definition of protective conductor;
– improved specification of mechanical characteristics of the earth electrode;

– introduction of earth electrode for protection against electric shock and lighting protection;

– annexes describing concrete-embedded foundation earth electrodes and soil-embedded

earth electrode.
The text of this standard is based on the following documents:
---------------------- Page: 6 ----------------------
60364-5-54  IEC:2011 – 5 –
FDIS Report on voting
64/1755/FDIS 64/1766/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.

It has the status of a basic safety publication in accordance with IEC Guide 104.

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

The reader's attention is drawn to the fact that Annex E lists all of the "in-some-country"

clauses on differing practices of a less permanent nature relating to the subject of this

standard.

A list of all parts in the IEC 60364 series, under the general title: Low-voltage electrical

installations, can be found on the IEC website.

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.
---------------------- Page: 7 ----------------------
– 6 – 60364-5-54  IEC:2011
INTRODUCTION

Clause numbering is sequential, preceded by the number of this Part. Numbering of figures

and tables takes the number of this part followed by a sequential number, i.e. Table 54.1,

54.2, etc. Numbering of figures and tables in annexes takes the letter of the annex, followed

by the number of the part, followed by a sequential number, e.g. A.54.1, A.54.2, etc.

---------------------- Page: 8 ----------------------
60364-5-54  IEC:2011 – 7 –
LOW-VOLTAGE ELECTRICAL INSTALLATIONS –
Part 5-54: Selection and erection of electrical equipment –
Earthing arrangements and protective conductors
541 General
541.1 Scope

This part of IEC 60364 addresses the earthing arrangements and protective conductors

including protective bonding conductors in order to satisfy the safety of the electrical

installation.
541.2 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 60364-4-41:2005, Low-voltage electrical installations – Part 4-41: Protection for safety –

Protection against electric shock

IEC 60364-4-44:2007, Low-voltage electrical installations – Part 4-44: Protection for safety –

Protection against voltage disturbances and electromagnetic disturbances

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

of electrical equipment – Common rules

IEC 60439-2, Low-voltage switchgear and controlgear assemblies – Part 2: Particular

requirements for busbar trunking systems (busways)

IEC 61439-1, Low-voltage switchgear and controlgear assemblies – Part 1: General rules

IEC 61439-2, Low-voltage switchgear and controlgear assemblies – Part 2: Power switchgear

and controlgear assemblies

IEC 60724, Short-circuit temperature limits of electric cables with rated voltages of 1 kV (U =

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

IEC 60909-0, Short-circuit currents in three-phase a.c. systems – Part 0: Calculation of

currents

IEC 60949, Calculation of thermally permissible short-circuit currents, taking into account

non-adiabatic heating effects

IEC 61140:2001, Protection against electric shock – Common aspects for installation and

equipment
IEC 61534-1, Powertrack systems – Part 1: General requirements
IEC 62305 (all parts) Protection against lightning

IEC 62305-3:2006, Protection against lightning – Part 3: Physical damage to structures and

life hazard
---------------------- Page: 9 ----------------------
– 8 – 60364-5-54  IEC:2011
541.3 Terms and definitions

For the purposes of this document, the terms and definitions of IEC 61140, together with the

following definitions, apply.

Definitions used for earthing arrangements, protective conductors and protective bonding

conductors are illustrated in Annex B and listed below:
541.3.1
exposed-conductive-part

conductive part of equipment which can be touched and which is not normally live, but which

can become live when basic insulation fails
[IEC 60050-826:2004, 826-12-10]
541.3.2
extraneous-conductive-part

conductive part not forming part of the electrical installation and liable to introduce an electric

potential, generally the electric potential of a local earth
[IEC 60050-825:2004, IEV 826-12-11]
541.3.3
earth electrode

conductive part, which may be embedded in the soil or in a specific conductive medium, e.g.

concrete, in electrical contact with Earth
[IEC 60050-826:2004, 826-13-05, modified]
541.3.4
concrete-embedded foundation earth electrode

earth electrode embedded in concrete of a building foundation, generally in the form of a

closed loop
[IEC 60050-826:2004, 826-13-08, modified]
541.3.5
soil-embedded foundation earth electrode

earth electrode buried in the soil under a building foundation, generally in the form of a closed

loop
[IEC 60050-826:2004, 826-13-08, modified]
541.3.6
protective conductor

conductor provided for purposes of safety, for example protection against electric shock

[IEC 60050-826:2004, 826-13-22]

NOTE Examples of a protective conductor include a protective bonding conductor, a protective earthing conductor

and an earthing conductor when used for protection against electric shock.
---------------------- Page: 10 ----------------------
60364-5-54  IEC:2011 – 9 –
541.3.7
protective bonding conductor
protective conductor provided for protective-equipotential-bonding
[IEC 60050-826:2004, 826-13-24]
541.3.8
earthing conductor

conductor which provides a conductive path, or part of the conductive path, between a given

point in a system or in an installation or in equipment and an earth-electrode network

[IEC 60050-826:2004, 826-13-12]

NOTE For the purposes of this part of IEC 60364, an earthing conductor is the conductor which connects the

earth electrode to a point in the equipotential bonding system, usually the main earthing terminal.

541.3.9
main earthing terminal
main earthing busbar

terminal or busbar which is part of the earthing arrangement of an installation and enabling

the electrical connection of a number of conductors for earthing purposes
[IEC 60050-826:2004, 826-13-15]
541.3.10
protective earthing conductor
protective conductor provided for protective earthing
[IEC 60050-826:2004, 826-13-23]
541.3.11
functional earthing

earthing a point or points in a system or in an installation or in equipment, for purposes other

than electrical safety
[IEC 60050-826:2004, IEV 826-13-10]
541.3.12
earthing arrangement

all the electrical connections and devices involved in the earthing of a system, installation or

an equipment
[IEC 60050-195:2004, 195-02-20]
542 Earthing arrangements
542.1 General requirements

542.1.1 The earthing arrangements may be used jointly or separately for protective and

functional purposes according to the requirements of the electrical installation. The

requirements for protective purposes shall always take precedence.

542.1.2 Where provided, earth electrodes within an installation shall be connected to the

main earthing terminal using an earthing conductor.
NOTE An installation does not need to have its own earth electrode.
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– 10 – 60364-5-54  IEC:2011

542.1.3 Where the supply to an installation is at high voltage, requirements concerning the

earthing arrangements of the high voltage supply and of the low-voltage installation shall also

comply with Clause 442 of IEC 60364-4-44:2007.

542.1.4 The requirements for earthing arrangements are intended to provide a connection to

earth which:
– is reliable and suitable for the protective requirements of the installation;

– can carry earth fault currents and protective conductor currents to earth without danger

from thermal, thermo-mechanical and electromechanical stresses and from electric shock

arising from these currents;
– if relevant, is also suitable for functional requirements;

– is suitable for the foreseeable external influences (see IEC 60364-5-51), e.g. mechanical

stresses and corrosion.

542.1.5 Consideration shall be given to the earthing arrangements where currents with high

frequencies are expected to flow (see Clause 444 of IEC 60364-4-44:2007).

542.1.6 Protection against electric shock, as stated in IEC 60364-4-41, shall not be

adversely affected by any foreseeable change of the earth electrode resistance (e.g. due to

corrosion, drying or freezing).
542.2 Earth electrodes

542.2.1 The type, materials and dimensions of earth electrodes shall be selected to

withstand corrosion and to have adequate mechanical strength for the intended lifetime.

NOTE 1 For corrosion, the following parameters may be considered: the soil pH at the site, soil resistivity, soil

moisture, stray and leakage a.c. and d.c. current, chemical contamination, and proximity of dissimilar materials.

For materials commonly used for earth electrodes, the minimum sizes, from the point of view

of corrosion and mechanical strength, when embedded in the soil or in concrete, shall be as

specified in Table 54.1.

NOTE 2 The minimum thickness of protective coating is greater for vertical earth electrodes than for horizontal

earth electrodes because of their greater exposure to mechanical stresses while being embedded.

If a lightning protection system is required, 5.4 of IEC 62305-3:2006 applies.
---------------------- Page: 12 ----------------------
60364-5-54  IEC:2011 – 11 –
Table 54.1 – Minimum size of commonly used earth electrodes, embedded in soil or
concrete used to prevent corrosion and provide mechanical strength
Cross- Thickness
Weight of
Diameter sectional Thickness of coating/
coating
Material and surface Shape
area sheathing
2 2
mm mm mm g/m µm
Steel embedded in Round wire 10
concrete (bare, hot
Solid tape or strip 75 3
galvanized or stainless)
Strip or shaped strip/plate
90 3 500 63
– Solid plate – Lattice plate
Round rod installed
16 350 45
vertically
Round wire installed
10 350 45
c horizontally
Steel hot-dip galvanized
Pipe 25 2 350 45
Stranded
70
(embedded in concrete)
Cross profile installed
(290) 3
vertically
Round rod installed
Steel copper-sheathed (15) 2 000
vertically
Round rod installed e
14 250
vertically
Steel with electro-
Round wire installed
deposited copper coating (8) 70
horizontally
Strip installed horizontally 90 3 70
Strip or shaped strip/plate 90 3
Round rod installed
vertically
Stainless steel
Round wire installed
horizontally
Pipe 25 2
Strip 50 2
Round wire installed
(25) 50
horizontally
Solid round rod installed
(12) 15
vertically
1,7 for
Copper
individual
Stranded wire
(25) 50
strands of
wire
Pipe 20 2
Solid plate (1,5) 2
Lattice plate 2

NOTE Values in brackets are applicable for protection against electric shock only, while values not in brackets are

applicable for lightning protection and for protection against electric shock.
Chromium ≥16 %, Nickel ≥5 %, Molybdenum ≥2 %, Carbon ≤0,08 %.
As rolled strip or slit strip with rounded edges.
The coating shall be smooth, continuous and free from flux stains.

Where experience shows that the risk of corrosion and mechanical damage is extremely low, 16 mm² can be used.

This thickness is provided to withstand mechanical damage of copper coating during the installation process. It may

---------------------- Page: 13 ----------------------
– 12 – 60364-5-54  IEC:2011

be reduced to not less than 100 µm where special precautions to avoid mechanical damage of copper during the

installation process (e.g. drilled holes or special protective tips) are taken according to the manufacturer’s

instructions.

542.2.2 The efficacy of any earth electrode depends on its configuration and upon local soil

conditions. One or more earth electrodes suitable for the soil conditions and the value of

resistance to earth required shall be selected.
Annex D gives methods of estimation of earth electrode resistance.
542.2.3 The following are examples of earth electrodes which may be used:
– concrete-embedded foundation earth electrode;
NOTE For more information see Annex C.
– soil-embedded foundation earth electrode;

– metallic electrode embedded directly in soil vertically or horizontally (e.g. rods, wires,

tapes, pipes or plates);

– metal sheath and other metal coverings of cables according to local conditions or

requirements;

– other suitable underground metalwork (e.g. pipes) according to local conditions or

requirements;

– welded metal reinforcement of concrete (except pre-stressed concrete) embedded in the

earth.

542.2.4 When selecting the type and embedded depth of an earth electrode, consideration

shall be given to possible mechanical damage and to local conditions to minimize the effect of

soil drying and freezing.

542.2.5 Consideration shall be given to electrolytic corrosion when using different materials

in an earthing arrangement. For external conductors (e.g. earthing conductor) connected to a

concrete-embedded foundation earth electrode, the connection made from hot-dip galvanized

steel shall not be embedded in the soil.

542.2.6 The earthing arrangement shall not rely on a metallic pipe for flammable liquids or

gases as the earth electrode and their buried length shall not be considered when

dimensioning the earth electrode.
NOTE This requirement does not preclude the protective equipotential bo
...