IEC 60670-24:2024

IEC 60670-24 ®
Edition 3.0 2024-12
EXTENDED VERSION
INTERNATIONAL
STANDARD
colour
inside
This full version of IEC 60670-24:2024 includes the content of the references made to
IEC 60670-1:2024
Boxes and enclosures for electrical accessories for household and similar fixed
electrical installations –
Part 24: Particular requirements for enclosures for housing protective devices
and other power dissipating electrical equipment
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.

IEC Secretariat Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
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 IEC Products & Services Portal - products.iec.ch
The advanced search enables to find IEC publications by a Discover our powerful search engine and read freely all the
variety of criteria (reference number, text, technical publications previews, graphical symbols and the glossary.
committee, …). It also gives information on projects, replaced With a subscription you will always have access to up to date
and withdrawn publications. content tailored to your needs.

IEC Just Published - webstore.iec.ch/justpublished
Electropedia - www.electropedia.org
Stay up to date on all new IEC publications. Just Published
The world's leading online dictionary on electrotechnology,
details all new publications released. Available online and once
containing more than 22 500 terminological entries in English
a month by email.
and French, with equivalent terms in 25 additional languages.

Also known as the International Electrotechnical Vocabulary
IEC Customer Service Centre - webstore.iec.ch/csc
(IEV) online.
If you wish to give us your feedback on this publication or need

further assistance, please contact the Customer Service
Centre: sales@iec.ch.
IEC 60670-24 ®
Edition 3.0 2024-12
EXTENDED VERSION
INTERNATIONAL
STANDARD
colour
inside
This full version of IEC 60670-24:2024 includes the content of the references made to
IEC 60670-1:2024
Boxes and enclosures for electrical accessories for household and similar fixed
electrical installations –
Part 24: Particular requirements for enclosures for housing protective devices
and other power dissipating electrical equipment
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.120.10 ISBN 978-2-8327-0115-7

– 2 – IEC 60670-24:2024 EXV © IEC 2024
CONTENTS
FOREWORD . 7
1 Scope . 10
2 Normative references . 10
3 Terms and definitions . 12
4 General requirements . 17
5 General remarks on tests . 17
5.1 Test conditions and number of samples . 17
5.2 Compliance general requirement . 17
6 Ratings . 17
7 Classification . 18
8 Marking . 19
8.1 General . 19
8.2 Durability of the marking on the boxes and enclosures . 20
9 Dimensions. 22
10 Protection against electric shock . 22
11 Provision for earthing . 22
11.1 Boxes and enclosures with exposed conductive parts . 22
11.2 Boxes and enclosures of insulating material classified according to 7.2.2.2
and 7.2.2.3 . 23
11.3 Boxes or enclosures with removable sides according to 7.1.2 . 25
11.4 Earthing terminal threads . 25
12 Construction . 26
12.1 General . 26
12.2 Lids, covers or cover-plates or parts of them . 26
12.2.1 General . 26
12.2.2 Screw-type fixing . 26
12.2.3 Non-screw-type fixing operable without the use of a tool or a key . 26
12.2.4 Non-screw-type fixing operable with the use of a tool or a key . 32
12.3 Drain holes . 33
12.4 Mounting of enclosures . 33
12.5 Boxes and enclosures with inlets for flexible cables . 33
12.6 Boxes and enclosures with inlets for applications other than flexible cables . 33
12.7 Boxes and enclosures with a cable anchorage(s) . 34
12.8 Boxes and enclosures with cable retention means . 35
12.9 Knock-outs intended to be removed by mechanical impact . 36
12.9.1 General . 36
12.9.2 Knock-out retention . 36
12.9.3 Knock-out removal . 36
12.9.4 Flat surfaces surrounding knock-outs . 37
12.10 Screw fixings . 37
12.11 Fixing of boxes and enclosures classified according to 7.2.1 . 38
12.12 Fixing of flush type and semi-flush type boxes and enclosures classified
according to 7.2.2.1 . 41
12.13 Boxes and enclosures classified according to 7.2.2.2 and 7.2.2.3 . 42
12.13.1 General . 42
12.13.2 Boxes intended for mounting on a wooden structural member of a wall . 42

12.13.3 Boxes intended for mounting to a wooden structural member of a ceiling . 42
12.13.4 Boxes intended for mounting to a steel-stud structural member of a wall . 42
12.13.5 Internal volume of boxes and enclosures classified according to 7.2.2.2
and 7.2.2.3 . 44
12.13.6 Boxes intended for mounting in a finished structure . 44
12.14 Cable gland entry . 44
12.15 Boxes and enclosures with inlets or spouts (hubs) for conduits . 45
12.16 Internal volume of boxes and enclosures . 45
13 Resistance to ageing, protection against ingress of solid objects and against
harmful ingress of water . 46
13.1 Resistance to ageing . 46
13.2 Protection against the ingress of solid objects . 48
13.3 Protection against harmful ingress of water . 49
14 Insulation resistance and electric strength . 53
15 Mechanical strength . 55
15.1 General . 55
15.2 Impact test at low temperature . 55
15.3 Compression test . 57
15.4 Impact test for boxes and enclosures . 57
15.5 Compression test for enclosures made of natural or synthetic rubber or a
mixture of both . 62
15.6 Test for boxes and enclosures declared with IK code . 64
16 Resistance to heat . 64
16.1 Parts of insulating material necessary to retain current-carrying parts . 64
16.2 Parts of insulating material not necessary to retain current-carrying parts . 65
16.3 Boxes and enclosures of insulating materials classified according to 7.2.2.2
or 7.2.2.3 . 65
16.3.1 Mechanical strength. 65
16.3.2 Parts of insulating material necessary to retain parts of the earthing
circuit . 66
17 Creepage distances, clearances and distances through sealing compound . 66
18 Resistance of insulating material to abnormal heat and fire . 67
19 Resistance to tracking . 69
20 Resistance to corrosion . 70
21 Electromagnetic compatibility (EMC) . 70
101 Verification of the maximum capability to dissipate power (P ) . 70
de
102 Verification of temperature rise . 77
Annex A (informative) Examples of enclosures and parts thereof . 79
Annex B (normative) Test for boxes and enclosures declared with IK code . 80
Annex AA (normative) Instructions to be given by the manufacturer of the GP
enclosure to the installer on how to integrate accessories, and providing an example of
calculation . 81
AA.1 Selection of the GP enclosure . 81
AA.2 Diversity factor . 82
AA.3 Markings . 82
AA.4 Test and verification to be carried out by the installer . 83
AA.5 Example of calculation without electronic devices . 86
AA.6 Example calculation to take into account the power loss of electronic devices . 88

– 4 – IEC 60670-24:2024 EXV © IEC 2024
Annex BB (normative) Instructions to be given by the manufacturer of the PD
enclosure to the installer on how to integrate accessories . 92
BB.1 General . 92
BB.2 Rated current and main characteristics . 92
BB.3 Devices to be integrated by the installer. 92
BB.4 Dimensions . 92
BB.5 Connections . 93
BB.6 Protection against electric shock . 93
BB.7 IP degree and IK code . 93
BB.8 Wiring . 93
Annex CC (normative) Additional requirements for enclosures exposed to direct
sunlight . 94
Annex DD (normative) Additional requirements for enclosures to accommodate
multimedia and communication equipment . 95
DD.1 Overview. 95
DD.2 Instructions . 95
DD.3 Protection against electric shock . 95
DD.4 Construction of separate area to accommodate multimedia equipment. 95
DD.5 Fixing of multimedia equipment . 96
DD.6 Verification of temperature rise . 96
Annex EE (normative) Additional requirements for enclosures for use with connected
devices or equipment . 97
EE.1 General . 97
EE.2 Application . 97
EE.3 General requirements . 97
EE.4 Additional classification . 97
EE.5 Instructions . 97
EE.6 Marking . 98
EE.7 Construction requirements . 98
EE.8 Verification. 99
EE.9 EMC aspects . 100
Bibliography . 101

Figure 1 – Examples of membranes and grommets . 14
Figure 2 – Test piston dimensions. 21
Figure 4 – Earthing strap . 24
Figure 5 – Test strap . 24
Figure 6 – Arrangement for test on covers or cover-plates (see 12.2.3.2 and 12.2.3.3) . 28
Figure 7 – Gauge for the verification of the outline of lids, covers or cover-plates . 29
Figure 8 – Examples of application of the gauge of Figure 7 on covers fixed without
screws on a mounting surface or supporting surface . 30
Figure 9 – Compliance criteria of application of the gauge of Figure 7 . 31
Figure 10 – Gauge for verification of grooves, holes and reverse tapers . 32
Figure 11 – Sketch showing the direction of application of the gauge of Figure 10 . 32
Figure 12 – Apparatus for testing the cable anchorage . 35
Figure 13 – Example of mounting block for boxes to be embedded in masonry (flush
type and semi-flush type) . 40
Figure 14 – Example of the fixing of the auxiliary device mounted on a specimen . 40

Figure 15 – Example of test apparatus for the test . 41
Figure 17 – Test of the force and measurement of the displacement . 43
Figure 18 – Volume measurement. 46
Figure 19 – Reference surfaces for boxes and enclosures . 50
Figure 20 – Test wall . 51
Figure 21 – Example of the protected volume . 53
Figure 22 – Apparatus for impact test at low temperature. 56
Figure 23 – Mounting block for flush-type boxes and enclosures in order to apply
blows on the rear surface . 58
Figure 24 – Sequence of blows for parts A, B, C, D, E, F and G . 61
Figure 25 – Test devices for load compression test for enclosures made of natural or

synthetic rubber or a mixture of both . 64
Figure 26 – Rigid crossbar . 66
Figure 27 – Diagrammatic representation of the glow-wire test . 69
Figure 101 – Arrangement for the verification of the maximum capability to dissipate
power (P ) and for verification of temperature rise of surface type enclosures . 72
de
Figure 102 – Heating resistor for the verification of the maximum capability to dissipate
power (P ) . 73
de
Figure 103 – Position of the resistor for enclosures designed or intended to be fitted
with rail mounting modular accessories and electrical equipment . 74
Figure 104 – Position of the resistor(s) for enclosures other than those designed or
intended to be fitted with rail mounting accessories and electrical equipment . 75
Figure 105 – Position of the resistor(s) for enclosures other than those designed or
intended to be fitted with rail mounting accessories and electrical equipment and
allowing the mounting of several accessories and electrical equipment in different
positions . 76
Figure A.1 – Examples of enclosures and parts thereof. 79
Figure AA.1 – Diagram of the equipped GP enclosure . 86
Figure AA.2 – Diagram of the equipped GP enclosure . 89

Table 1 – Classification of boxes and enclosures . 18
Table 2 – Forces to be applied to lids, covers, cover-plates or actuating members
whose fixing is not dependent on screws . 27
Table 3 – Forces and torques to be applied to cable anchorages . 34
Table 4 – Tightening torques for the verification of the mechanical strength of screws . 38
Table 5 – Torque test values for cable glands . 45
Table 6 – Test voltage for electric strength test . 54
Table 7 – Determination of parts A, B, C, D E, F and G . 58
Table 8 – Height of fall for impact test . 59
Table 101 – Creepage distances, clearances and distances through sealing compound . 67
Table 102 – Diversity factor . 78
Table 103 – Temperatures of accessible surfaces . 78
Table AA.1 – Diversity factor. 82
Table AA.2 – Tests and verifications . 83
Table AA.3 – Calculation of P . 87
dp
– 6 – IEC 60670-24:2024 EXV © IEC 2024
Table AA.4 – Calculation of P . 87
au
Table AA.5 – Calculation of P . 90
dp
Table AA.6 – Calculation of P . 91
au
Table AA.7 – Calculation of P . 91
el
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
BOXES AND ENCLOSURES FOR ELECTRICAL ACCESSORIES FOR
HOUSEHOLD AND SIMILAR FIXED ELECTRICAL INSTALLATIONS –

Part 24: Particular requirements for enclosures for housing protective
devices and other power dissipating electrical equipment

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) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
This extended version (EXV) of the official IEC Standard provides the user with the full
content of the Standard.
to IEC 60670-1:2024.
The specific content of IEC 60670-24:2024 is displayed on a blue background.

– 8 – IEC 60670-24:2024 EXV © IEC 2024
IEC 60670-24 has been prepared by subcommittee 23B: Plugs, socket-outlets and switches, of
IEC technical committee 23: Electrical accessories. It is an International Standard.
This third edition cancels and replaces the second edition published in 2011. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) revision of requirements for protection against electric shock in Clause 10;
b) addition of requirements for functional earthing in 11.101;
c) revision of the requirements for fixing of flush type and semi-flush type enclosures in 12.12;
d) revision of the requirements for resistance of insulating material to abnormal heat and to
fire in Clause 18;
e) addition of calculations to take into account the power loss of electronic devices in
Clause AA.6;
f) addition of tests and requirements for enclosures exposed to direct sunlight with the related
Annex CC;
g) addition of tests and requirements for enclosures with separate area to accommodate
multimedia-equipment with the related Annex DD;
h) addition of tests and requirements for enclosures used with connected devices or equipment
with the related Annex EE.
The text of this International Standard is based on the following documents:
Draft Report on voting
23B/1536/FDIS 23B/1554/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all parts in the IEC 60670 series, published under the general title Boxes and enclosures
for electrical accessories for household and similar fixed installations, can be found on the IEC
website.
This document is to be used in conjunction with IEC 60670-1:2024. It lists the changes
necessary to convert that standard into a specific standard for housing protective devices and
other power dissipating electrical equipment.
Where this document states "addition", "modification" or "replacement", the relevant
requirement, test specifications or explanatory matter in IEC 60670-1:2024 shall be adapted
accordingly.
Clauses and subclauses, notes, figures or tables which are additional to those in
IEC 60670-1:2024 are numbered starting from 101.
Additional annexes to IEC 60670-1:2024 are numbered AA, BB, etc.

In this publication the following print types are used:
• requirements proper: in roman type.
• test specifications: in italic type.
• notes: in smaller roman type.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn, or
• revised.
IMPORTANT – The "colour inside" logo on the cover page of this document indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this document using a colour printer.

– 10 – IEC 60670-24:2024 EXV © IEC 2024
BOXES AND ENCLOSURES FOR ELECTRICAL ACCESSORIES FOR
HOUSEHOLD AND SIMILAR FIXED ELECTRICAL INSTALLATIONS –

Part 24: Particular requirements for enclosures for housing protective
devices and other power dissipating electrical equipment

1 Scope
This part of IEC 60670 applies to enclosures and parts of them for housing protective devices
and other power dissipating electrical equipment intended to be used with a rated voltage not
exceeding 400 V and a total incoming load current not exceeding 125 A for household and
similar fixed electrical installations.
These enclosures are intended to be installed in locations where unskilled persons have access.
They are intended to be equipped with electrical equipment by skilled persons (installers).
These enclosures are intended to be installed where the prospective short circuit current does
not exceed 10 kA unless they are protected by current limiting protective devices with a cut-off
current not exceeding 17 kA.
Enclosures complying with this document are suitable for use at ambient temperature not
normally exceeding 40 °C, but their average temperature over a period of 24 h does not exceed
35 °C, with a lower limit of the ambient air temperature of −5 °C.
An enclosure which is an integral part of an electrical accessory and provides protection against
external influences (e.g. mechanical impacts, ingress of solid objects or of water), is covered
by the relevant standard for such an accessory.
This document does not apply to a low-voltage switchgear and controlgear assembly as defined
in the IEC 60439 series or IEC 61439 series nor to a main entrance panel which can be part of
the distribution board.
This document does not apply to surface type boxes, flush and semi-flush type boxes suitable
for the housing of accessories for household and similar use such as switches, electronic
switches, socket-outlets, which are covered by IEC 60670-1 only.
NOTE 1 Enclosures according to this document are mainly used for distribution board for housing protective devices
and other power dissipating electrical equipment and are installed at the beginning of the electrical circuit whereas
boxes according to IEC 60670-1 are installed at the end of it.
NOTE 2 A main entrance panel is a set composed of a panel or an enclosure equipped with a meter and/or the
main incoming device. Main entrance panels comply with their appropriate standards or the requirements of the local
supplier, if any.
NOTE 3 In the following country this document cannot be used in installations with a 230 V single-phase supply
rated up to 100 A that is under the control of ordinary persons. Integration of mechanical and electrical devices into
an enclosure must be verified by compliance with IEC 61439-3 [British standard EN 61439-3]: UK.
NOTE 4 In the following country this document can only be used for GP enclosures with the instructions according
to Annex A. For the other types of enclosures the integration of mechanical and electrical devices into an enclosure
is verified by compliance with DS EN 61439-3: DK.
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 60068-2-75:2014, Environmental testing – Part 2-75: Tests – Test Eh: Hammer tests
IEC 60112:2020, Method for the determination of the proof and the comparative tracking indices
of solid insulating materials
IEC 60364-4-41:2005, Low-voltage electrical installations – Part 4-41: Protection for safety –
Protection against electric shock
IEC 60364-4-41:2005/AMD1:2017
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/AMD1:2021
IEC 60417, Graphical symbols for use on equipment, available at http://www.graphical-
symbols.info/equipment
IEC 60423:2007, Conduit systems for cable management – Outside diameters of conduits for
electrical installations and threads for conduits and fittings
IEC 60529:1989, Degrees of protection provided by enclosures (IP Code)
IEC 60529:1989/AMD1:1999
IEC 60529:1989/AMD2:2013
IEC 60664-1, Insulation coordination for equipment within low-voltage supply systems – Part 1:
Principles, requirements and tests
IEC 60695-2-11:2021, Fire hazard testing – Part 2-11: Glowing/hot-wire based test methods –
Glow-wire flammability test method for end-products
IEC 60695-10-2:2014, Fire hazard testing – Part 10-2: Abnormal heat – Ball pressure test
IEC 60898-1, Electrical accessories – Circuit-breakers for overcurrent protection for household
and similar installations – Part 1: Circuit-breakers for a.c. operation
60981:2019, Extra-heavy duty rigid steel conduits
IEC
IEC 61008-2-1, Residual current operated circuit-breakers without integral overcurrent
protection for household and similar uses (RCCB's) – Part 2-1: Applicability of the general rules
to RCCB's functionally independent of line voltage
IEC 61009-2-1, Residual current operated circuit-breakers with integral overcurrent protection
for household and similar uses (RCBO's) – Part 2-1: Applicability of the general rules to RCBO's
functionally independent of line voltage
IEC 61032:1997, Protection of persons and equipment by enclosures – Probes for verification
IEC 61140:2016, Protection against electric shock – Common aspects for installation and
equipment
IEC 62262:2002, Degrees of protection provided by enclosures for electrical equipment against
external mechanical impacts (IK code)
IEC 62262:2002/AMD1:2021
ISO/IEC Guide 51, Safety aspects – Guidelines for their inclusion in standards

– 12 – IEC 60670-24:2024 EXV © IEC 2024
ISO/IEC 11801-1:2017, Information technology – Generic cabling for customer premises –
Part 1: General requirements
ISO 178:2019, Plastics – Determination of flexural properties
ISO 179-1:2010, Plastics – Determination of Charpy impact properties – Part 1:
Non-instrumented impact test
ISO 4892-2:2013, Plastics – Methods of exposure to laboratory light sources – Part 2:
Xenon-arc lamps
ISO 4892-2:2013/AMD1:2021
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1
enclosure
combination of parts, such as boxes, backplates, covers, cover-plates, lids, box extensions,
accessories, etc., providing after assembly and installation as in normal use, an appropriate
protection against external influences, and a defined protection against contact with enclosed
live parts from any accessible direction
Note 1 to entry: See Annex A.
3.2
box
part of an enclosure provided with means for fixing a cover, cover-plate, accessory, etc., and
intended to receive accessories (such as socket-outlets, switches, etc.)
Note 1 to entry: The accessory can be entirely or partly inside the enclosure.
3.3
box extension
part of an enclosure which is intended to extend a box for the purpose of either increasing the
internal volume of the box or enclosure or to adjust for mounting the box flush or semi-flush
with the finished surface of a wall or the like
3.4
backplate
part of a surface mounting enclosure provided with means for fixing a cover, cover-plate,
accessory (such as socket-outlets, switches, etc)
3.5
lid
cover
cover-plate
part of an enclosure, not integral with or part of an accessory, which may either retain an
accessory in position or enclose it

3.6
raised cover
cover intended for mounting directly onto a box to provide for the attachment of accessories
and to increase the internal volume of the enclosure
Note 1 to entry: The centre portion of the cover is raised to accommodate a specific wall or ceiling thickness and
to permit the mounting of the accessory on it, flush with the surface of the wall or ceiling.
3.7
exposed conductive part
conductive part of electrical equipment, which can be touched, and which is not normally live,
but which can become live when basic insulation fails
3.8
surface mounting enclosure
surface mounting box
box or enclosure which is intended for mounting on a surface
Note 1 to entry: See Annex A.
3.9
flush-mounting box
flush-mounting enclosure
box or enclosure which is intended for mounting flush with the surface
Note 1 to entry: See Annex A.
3.10
semi-flush mounting box
semi-flush mounting enclosure
box or enclosure which is intended to fit within a mounting surface and partially projects from
the mounting surface
3.11
cable gland
device designed to permit the entry of a cable, flexible cable or insulated conductor into an
enclosure, and which provides sealing and retention and eventually may also provide other
functions such as earthing, bonding, insulation, cable guarding, strain relief or a combination of
these
3.12
seal
material used to fill up the space between the inside of a gland and the cable passing through,
usually compressed by the gland and thereby forming a joint
3.13
gasket
material introduced between mating surfaces of an enclosure which when under compression
forms a joint
3.14
grommet
component used to support and protect the cable or conduit at the point of entry; it may also
prevent the ingress of moisture or contaminants
Note 1 to entry: See Figure 1.
[SOURCE: IEC 60050-581:2008, 581-27-19, modified – The words "part of", "or an accessory"
and "wires or" have been omitted from the definition and "or conduit" added; Note 1 to entry
added.]
– 14 – IEC 60670-24:2024 EXV © IEC 2024

Key
1 box
2 entry membrane
3 enclosure
4 protective membrane
5 grommet
6 electrical accessory
Figure 1 – Examples of membranes and grommets
3.15
entry membrane
component or an integral part of an enclosure used to protect the cable which may be used to
support the cable or conduit at the point of entry
Note 1 to entry: An entry membrane may also prevent the ingress of moisture or contaminants and may be part of
a grommet (see Figure 1).
3.16
protective membrane
component or an integral part of an enclosure that is not intended to be penetrated in normal
use and is intended to provide protection against ingress of water or solid objects and/or to
allow the operation of an acc
...