IEC 60364-7-721:2017

Low-voltage electrical installations - Part 7-721: Requirements for special installations or locations - Electrical installations in caravans and motor caravans

IEC 60364-7-721:2017 lays down particular requirements applying to electrical circuits and equipment intended for the use of the caravan for habitation purposes. This new edition includes the following significant technical changes with respect to the previous edition:
- a minimum height of not less than 500 mm above the base of the cylinders is now required for cables passing through the gas cylinder compartment;
- it is now required that each independent installation shall be provided with its own main isolating switch which shall disconnect all live conductors and which shall be suitably placed in a readily accessible location in the caravan.

Installations électriques à basse tension - Partie 7-721: Exigences pour les installations ou emplacements spéciaux - Installations électriques dans les caravanes et caravanes à moteur

IEC 60364-7-721:2017 s’applique aux circuits et matériels électriques des caravanes destinées à des fins de logement. Elles ne s’appliquent pas aux circuits et matériels électriques destinés à la propulsion. Elles ne s’appliquent pas aux installations électriques intérieures des maisons d’habitation mobiles, des caravanes résidentielles fixes et des unités transportables.
Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a) Une hauteur minimale supérieure ou égale à 500 mm au-dessus de la base des bombonnes est désormais exigée pour les câbles passant par le compartiment contenant la bombonne de gaz.
b) Il est désormais exigé que chaque installation indépendante soit fournie avec son dispositif général de sectionnement qui doit déconnecter tous les conducteurs actifs et qui doit être placé de façon appropriée et accessible dans la caravane.
c) La numérotation des articles relatifs aux mesures de protection non autorisées (obstacles, mise hors de portée, emplacements non conducteurs, liaison équipotentielle non reliée) a changé.

General Information

• Status: Published
• Publication Date: 14-Jun-2017
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 11.040 - Medical equipment
• ICS: 11.040.60 - Therapy equipment
• 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
• Drafting Committee: MT 33 - TC 64/MT 33
• Current Stage: PPUB - Publication issued
• Start Date: 30-Jun-2017
• Completion Date: 15-Jun-2017

Standards Content (Sample)

IEC 60364-7-721
®

Edition 2.0 2017-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE


Low-voltage electrical installations –
Part 7-721: Requirements for special installations or locations – Electrical
installations in caravans and motor caravans

Installations électriques à basse tension –
Partie 7-721: Exigences pour les installations ou emplacements spéciaux –
Installations électriques dans les caravanes et caravanes à moteur

IEC 60364-7-721:2017-06 (en-fr)

---------------------- Page: 1 ----------------------
THIS PUBLICATION IS COPYRIGHT PROTECTED
Copyright © 2017 IEC, Geneva, Switzerland

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.


Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite
ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie
et les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez
les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.

IEC Central Office Tel.: [phone]
3, rue de Varembé [e-mail]
CH-1211 Geneva 20 www.iec.ch
Switzerland

About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.

IEC publications search - webstore.iec.ch/advsearchform Electropedia - www.electropedia.org
The advanced search enables to find IEC publications by a The world's leading online dictionary on electrotechnology,
variety of criteria (reference number, text, technical containing more than 22 000 terminological entries in English
committee,…). It also gives information on projects, replaced and French, with equivalent terms in 16 additional languages.
and withdrawn publications. Also known as the International Electrotechnical Vocabulary

(IEV) online.
IEC Just Published - webstore.iec.ch/justpublished
Stay up to date on all new IEC publications. Just Published IEC Glossary - std.iec.ch/glossary
details all new publications released. Available online and 67 000 electrotechnical terminology entries in English and
once a month by email. French extracted from the Terms and Definitions clause of
IEC publications issued since 2002. Some entries have been
IEC Customer Service Centre - webstore.iec.ch/csc collected from earlier publications of IEC TC 37, 77, 86 and
If you wish to give us your feedback on this publication or CISPR.

need further assistance, please contact the Customer Service

Centre: [e-mail].


A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications IEC
Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la
plus récente, un corrigendum ou amendement peut avoir été publié.

Recherche de publications IEC - Electropedia - www.electropedia.org
webstore.iec.ch/advsearchform Le premier dictionnaire d'électrotechnologie en ligne au
La recherche avancée permet de trouver des publications IEC monde, avec plus de 22 000 articles terminologiques en
en utilisant différents critères (numéro de référence, texte, anglais et en français, ainsi que les termes équivalents dans
comité d’études,…). Elle donne aussi des informations sur les 16 langues additionnelles. Egalement appelé Vocabulaire
projets et les publications remplacées ou retirées. Electrotechnique International (IEV) en ligne.

IEC Just Published - webstore.iec.ch/justpublished Glossaire IEC - std.iec.ch/glossary
Restez informé sur les nouvelles publications IEC. Just 67 000 entrées terminologiques électrotechniques, en anglais
Published détaille les nouvelles publications parues. et en français, extraites des articles Termes et Définitions des
Disponible en ligne et une fois par mois par email. publications IEC parues depuis 2002. Plus certaines entrées
antérieures extraites des publications des CE 37, 77, 86 et
Service Clients - webstore.iec.ch/csc CISPR de l'IEC.

Si vous désirez nous donner des commentaires sur cette
publication ou si vous avez des questions contactez-nous:
[e-mail].

---------------------- Page: 2 ----------------------
IEC 60364-7-721

®


Edition 2.0 2017-06




INTERNATIONAL



STANDARD




NORME



INTERNATIONALE











Low-voltage electrical installations –

Part 7-721: Requirements for special installations or locations – Electrical

installations in caravans and motor caravans




Installations électriques à basse tension –

Partie 7-721: Exigences pour les installations ou emplacements spéciaux –


Installations électriques dans les caravanes et caravanes à moteur













INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE


INTERNATIONALE




ICS 29.020; 91.140.50 ISBN 978-2-8322-7406-4




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 – IEC 60364-7-721:2017 © IEC 2017
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
721 Electrical installations in caravans and motor caravans . 7
721.1 Scope . 7
721.2 Normative references . 7
721.3 Terms and definitions . 8
721.31 Purposes, supplies and structure . 8
721.313 Supplies . 8
721.4 Protection for safety . 9
721.41 Protection against electric shock . 9
721.411 Protective measure: automatic disconnection of supply . 9
721.413 Protective measure: electrical separation . 9
721.414 Protective measure: extra-low voltage provided by SELV and PELV . 9
721.415 Additional protection . 9
721.43 Protection against overcurrent . 10
721.5 Selection and erection of equipment . 10
721.51 Common rules . 10
721.510 Introduction . 10
721.512 Operational conditions and external influences . 10
721.514 Identification . 10
721.52 Wiring systems . 10
721.521 Types of wiring systems . 10
721.522 Selection and erection of wiring systems in relation to external
influences . 11
721.524 Cross-sectional areas of conductors . 11
721.526 Electrical connections . 11
721.528 Proximity of wiring systems to other services . 11
721.53 Isolation, switching and control . 12
721.536 Isolation and switching . 12
721.54 Earthing arrangements and protective conductors . 12
721.543 Protective conductors . 12
721.55 Other equipment . 12
Annex A (normative) Instructions for electricity supply . 14
Annex B (informative) Extra low-voltage DC installations . 15
Annex C (informative) Current-carrying capacities . 21
Annex D (informative) List of notes concerning certain countries . 24
Bibliography . 25

Figure C.721.1 – Graph for obtaining minimum cross-sectional area for conductors for
fixed wiring installations with a voltage drop of 0,8 V . 21
Figure C.721.2 – Graph for obtaining minimum cross-sectional area for conductors for
battery cable installations with a voltage drop of 0,3 V . 22

---------------------- Page: 4 ----------------------
IEC 60364-7-721:2017 © IEC 2017 – 3 –
Table 721.1 – Cross-sectional areas of flexible cords and cables for caravan
connection . 13
Table B.721.1 – Functional allocation and cross-sectional areas of cores for caravan

connectors . 18

---------------------- Page: 5 ----------------------
– 4 – IEC 60364-7-721:2017 © IEC 2017
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

LOW-VOLTAGE ELECTRICAL INSTALLATIONS –

Part 7-721: Requirements for special installations or locations –
Electrical installations in caravans and motor caravans

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 itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
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 60364-7-721 has been prepared by IEC technical committee 64:
Electrical installations and protection against electrical shock.
This bilingual version (2019-09) corresponds to the monolingual English version, published in
2017-06.
This second edition cancels and replaces the first edition published in 2007. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) A minimum height of not less than 500 mm above the base of the cylinders is now required
for cables passing through the gas cylinder compartment. Where cables have to run
through a compartment such cables shall be protected against mechanical damage by

---------------------- Page: 6 ----------------------
IEC 60364-7-721:2017 © IEC 2017 – 5 –
installation within a continuous conduit or duct passing through the compartment
(721.528.3.1).
b) It is now required that each independent installation shall be provided with its own main
isolating switch which shall disconnect all live conductors and which shall be suitably
placed in a readily accessible location in the caravan.(721.536.2.1.1)
c) The clause numbers for the protective measures not permitted (obstacles, placing out of
reach, non-conducting locations and earth-free local equipotential bonding) have been
changed.
The text of this International Standard is based on the following documents:
FDIS Report on voting
64/2200/FDIS 64/2210/RVD

Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
The French version of this standard has not been voted upon.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 60364 series, published under the general title Low-voltage
electrical installations, can be found on the IEC website.
The reader's attention is drawn to the fact that Annex D lists all of the “in-some-country”
clauses on differing practices of a less permanent nature relating to the subject of this
standard.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

---------------------- Page: 7 ----------------------
– 6 – IEC 60364-7-721:2017 © IEC 2017
INTRODUCTION
For the purpose of this part (IEC 60364-7-721) the requirements of the general Parts 1 to 6 of
IEC 60364 apply.
The IEC 60364-7-7XX parts of IEC 60364 contain particular requirements for special
installations or locations which are based on the requirements of the general parts of
IEC 60364 (IEC 60364-1 to IEC 60364-6). These IEC 60364-7-7XX parts are considered in
conjunction with the requirements of the general parts.
The particular requirements of this part of IEC 60364 supplement, modify or replace certain of
the requirements of the general parts of IEC 60364 being valid at the time of publication of
this part. The absence of reference to the exclusion of a part or a clause of a general part
means that the corresponding clauses of the general part are applicable (undated reference).
Requirements of other 7XX parts being relevant for installations covered by this part also
apply. This part may therefore also supplement, modify or replace certain of these
requirements valid at the time of publication of this part.
The clause numbering of this part follows the pattern and corresponding references of
IEC 60364. The numbers following the particular number of this part are those of the
corresponding parts, or clauses of the other parts of the IEC 60364 series, valid at the time of
publication of this part, as indicated in the normative references of this document (dated
reference).
If requirements or explanations additional to those of the other parts of the IEC 60364 series
are needed, the numbering of such items appears as 721.101, 721.102, 721.103 etc.
In the case where new or amended general parts with modified numbering were published
after this part was issued, the clause numbers referring to a general part in this 721 part may
no longer align with the latest edition of the general part. Dated references should be
observed.

---------------------- Page: 8 ----------------------
IEC 60364-7-721:2017 © IEC 2017 – 7 –
LOW-VOLTAGE ELECTRICAL INSTALLATIONS –

Part 7-721: Requirements for special installations or locations –
Electrical installations in caravans and motor caravans



721 Electrical installations in caravans and motor caravans
721.1 Scope
The particular requirements of this part of IEC 60364 apply to electrical installations in
caravans and motor caravans.
They apply to those electrical circuits and equipment intended for the use of the caravan for
habitation purposes.
They do not apply to those electrical circuits and equipment for automotive purposes.
They do not apply to the electrical installations of mobile homes, residential park homes and
transportable units.
NOTE 1 For mobile homes and residential park homes the general requirements apply.
NOTE 2 For transportable units see IEC 60364-7-717.
NOTE 3 For the purposes of this document, caravans and motor caravans are referred to as “caravans”
The particular requirements of some parts from the IEC 60364-7 series can also apply to such
installations in caravans, for example IEC 60364-7-701.
721.2 Normative references
The following documents are referred to in the text in such a way that some or all of their
content constitutes requirements 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 60038, IEC standard voltages
IEC 60309-2, Plugs, socket-outlets and couplers for industrial purposes – Part 2: Dimensional
interchangeability requirements for pin and contact-tube accessories
IEC 60332-1-2, Tests on electric and optical fibre cables under fire conditions – Part 1-2: Test
for vertical flame propagation for a single insulated wire or cable – Procedure for 1 kW pre-
mixed flame
IEC 60947-2, Low-voltage switchgear and controlgear – Part 2: Circuit-breakers
IEC 61008-1, Residual current operated circuit-breakers without integral overcurrent
protection for household and similar uses (RCCBs) – Part 1: General rules
IEC 61009-1, Residual current operated circuit-breakers with integral overcurrent protection
for household and similar uses (RCBOs) – Part 1: General rules
IEC 61084 (all parts), Cables trunking and ducting systems for electrical installations

---------------------- Page: 9 ----------------------
– 8 – IEC 60364-7-721:2017 © IEC 2017
IEC 61386 (all parts), Conduit systems for cable management
IEC 62423, Type F and Type B residual current operated circuit-breakers with and without
integral overcurrent protection for household and similar uses
721.3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
721.3.1
leisure accommodation vehicle
unit of living accommodation for temporary or seasonal occupation that may meet the
requirements for the construction and use of road vehicles
721.3.1.1
caravan
trailer leisure accommodation vehicle, used for touring, that meets the requirements for the
construction and use of road vehicles
721.3.1.2
motor caravan
self-propelled leisure accommodation vehicle, used for touring, that meets the requirements
for the construction and use of road vehicles
Note 1 to entry: A motor caravan is either adapted from a series production vehicle, or designed and built on an
existing chassis, with or without the driving cab, the accommodation being either fixed or dismountable.
721.3.1.3
mobile home
transportable leisure accommodation vehicle that includes means for mobility but does not
meet the requirements for the construction and use of road vehicles
721.3.1.4
residential park home
factory produced relocatable dwelling
721.31 Purposes, supplies and structure
721.313 Supplies
721.313.1 General
721.313.1.101 The nominal supply system voltage shall be selected from IEC 60038.
The nominal AC supply voltage of the installation of the caravan shall not exceed 230 V
single-phase, or 400 V three-phase.
The nominal DC supply voltage of the installation of the caravan shall not exceed 48 V.

---------------------- Page: 10 ----------------------
IEC 60364-7-721:2017 © IEC 2017 – 9 –
721.4 Protection for safety
721.41 Protection against electric shock
721.410.3.5
Add the following:
The protective measures of obstacles and placing out of reach as specified in Annex B of
IEC 60364-4-41:2005 shall not be used.
721.410.3.6
Add the following:
The protective measures of non-conducting locations and earth-free local equipotential
bonding as specified in Annex C of IEC 60364-4-41:2005 shall not be used.
NOTE This precludes the use of class 0 equipment.
721.411 Protective measure: automatic disconnection of supply
721.411.3.1.2 Protective equipotential bonding
Metal frame parts or thereto connected construction parts shall be connected through main
protective bonding conductors to the main earthing terminal within the caravan.
721.413 Protective measure: electrical separation
The protective measure: electrical separation shall not be used, except for a shaver socket-
outlet.
721.414 Protective measure: extra-low voltage provided by SELV and PELV
Any part of a caravan installation operating at extra-low voltage shall comply with the
requirements of Clause 414.
For extra-low voltage DC power sources, a maximum of 48 V are allowed. In exceptional
cases, when AC extra-low voltage is required, the voltage (rms) is not allowed to exceed
48 V.
The requirements of Part 721 are also applicable to extra low-voltage DC installation. See
Annex B for recommendations that can be applied in addition.
721.415 Additional protection
721.415.101 Additional protection: residual current protective devices (RCDs)
Addition:
Where protection by automatic disconnection of supply is used, a residual current device with
a rated residual operating current not exceeding 30 mA, complying with IEC 60947-2,
IEC 61008-1, IEC 61009-1 or IEC 62423 breaking all live conductors, shall be provided. Each
supply inlet shall be directly connected to its associated RCD.
NOTE This implies that there cannot be any taps or junctions in this connection.
Consideration should be given to the characteristics of the load in selection of the type of
RCD.

---------------------- Page: 11 ----------------------
– 10 – IEC 60364-7-721:2017 © IEC 2017
721.43 Protection against overcurrent
721.43.101 Final circuits
Each final circuit shall be protected by an overcurrent protective device which disconnects all
live conductors of that circuit.
721.5 Selection and erection of equipment
721.51 Common rules
721.510 Introduction
721.510.3 General
Where there is more than one electrically independent installation, each independent
installation shall be supplied by a separate connecting device and shall be segregated (in
accordance with general rules) such that supplies at different voltages cannot be
interconnected.
NOTE Independent installations. An installation is an assembly of associated electrical equipment having co-
ordinated characteristics to fulfil specific purposes.
721.512 Operational conditions and external influences
721.512.2 External influences
Consideration shall be given to the foreseeable external influences to which the caravan will
be subjected.
721.514 Identification
721.514.1 General
Instructions for use shall be provided with the caravan so that the caravan can be used safely.
The instructions shall comprise:
– a description of the installation;
– a description of the function of the RCD(s) and the use of the test button;
– a description of the function of the main isolating switch(es);
– the text of the instructions of Annex A.
– additional instructions necessary for user maintenance.
721.52 Wiring systems
721.521 Types of wiring systems
721.521.2 The wiring system shall use one or more of the following:
– insulated single-core cables, with flexible class 5 conductors, in non-metallic conduit or
non-metallic trunking system;
– insulated single-core cables, with stranded class 2 conductors (minimum of seven strands),
in non-metallic conduit or non-metallic trunking system;
– sheathed flexible cables.
All cables shall as a minimum meet the requirements of IEC 60332-1-2.
Non-metallic conduit systems shall comply with the relevant part of IEC 61386 (all parts).

---------------------- Page: 12 ----------------------
IEC 60364-7-721:2017 © IEC 2017 – 11 –
Cable trunking systems and cable ducting systems shall comply with the relevant part of
IEC 61084 (all parts).
721.522 Selection and erection of wiring systems in relation to external influences
721.522.7 Vibration (AH)
721.522.7.1 As the wiring will be subjected to vibration, all wiring shall be protected against
mechanical damage either by location or by enhanced mechanical protection. Wiring passing
through metalwork shall be protected by means of suitable bushes or grommets, securely
fixed in position. Precautions shall be taken to avoid mechanical damage due to sharp edges
or abrasive parts.
721.522.8 Other mechanical stresses (AJ)
721.522.8.1.3 All cables, unless enclosed in rigid conduit, trunking, or flexible conduit shall
be supported at intervals not exceeding 0,4 m for vertical runs and 0,25 m for horizontal runs.
721.524 Cross-sectional areas of conductors
2
721.524.1 The cross-sectional area of every conductor shall be not less than 1,5 mm
copper or copper equivalent.
721.526 Electrical connections
721.526.1.101 Addition:
Connections between cables or conductors shall only be made in connecting boxes or by
electrical equipment.
NOTE Connections also include junctions and taps.
721.528 Proximity of wiring systems to other services
721.528.3 Proximity to non-electrical services
721.528.3.1
Add the following at
...