IEC 60364-7-721:2017

IEC 60364-7-721 ®
Edition 2.0 2017-06
INTERNATIONAL
STANDARD
Low-voltage electrical installations –
Part 7-721: Requirements for special installations or locations – Electrical
installations in caravans and motor caravans

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IEC 60364-7-721 ®
Edition 2.0 2017-06
INTERNATIONAL
STANDARD
Low-voltage electrical installations –

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

installations in caravans and motor caravans

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.020; 91.140.50 ISBN 978-2-8322-4425-8

– 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

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

– 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
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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 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
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.
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.
A bilingual version of this
...