IEC 60670-22:2024

IEC 60670-22 ®
Edition 2.0 2024-12
EXTENDED VERSION
INTERNATIONAL
STANDARD
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inside
This full version of IEC 60670-22:2024 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 22: Particular requirements for connecting boxes and enclosures
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IEC 60670-22 ®
Edition 2.0 2024-12
EXTENDED VERSION
INTERNATIONAL
STANDARD
colour
inside
This full version of IEC 60670-22:2024 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 22: Particular requirements for connecting boxes and enclosures
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.120.10 ISBN 978-2-8327-0114-0

– 2 – IEC 60670-22:2024 EXV © IEC 2024
CONTENTS
FOREWORD . 6
1 Scope . 9
2 Normative references . 9
3 Terms and definitions . 10
4 General requirements . 15
5 General remarks on tests . 16
5.1 Test conditions and number of samples . 16
5.2 Compliance general requirement . 16
6 Ratings . 17
7 Classification . 17
8 Marking . 19
8.1 General . 19
8.2 Durability of the marking on the boxes and enclosures . 20
9 Dimensions. 21
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 . 25
12.1 General . 25
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 . 32
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 . 43
12.13.1 General . 43
12.13.2 Boxes intended for mounting on a wooden structural member of a wall . 43

12.13.3 Boxes intended for mounting to a wooden structural member of a ceiling . 43
12.13.4 Boxes intended for mounting to a steel-stud structural member of a wall . 43
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 . 45
12.14 Cable gland entry . 45
12.15 Boxes and enclosures with inlets or spouts (hubs) for conduits . 46
12.16 Internal volume of boxes and enclosures . 46
13 Resistance to ageing, protection against ingress of solid objects and against
harmful ingress of water . 48
13.1 Resistance to ageing . 48
13.2 Protection against the ingress of solid objects . 49
13.3 Protection against harmful ingress of water . 50
14 Insulation resistance and electric strength . 55
15 Mechanical strength . 57
15.1 General . 57
15.2 Impact test at low temperature . 58
15.3 Compression test . 59
15.4 Impact test for boxes and enclosures . 60
15.5 Compression test for enclosures made of natural or synthetic rubber or a
mixture of both . 65
15.6 Test for boxes and enclosures declared with IK code . 67
16 Resistance to heat . 67
16.1 Parts of insulating material necessary to retain current-carrying parts . 67
16.2 Parts of insulating material not necessary to retain current-carrying parts . 68
16.3 Boxes and enclosures of insulating materials classified according to 7.2.2.2
or 7.2.2.3 . 68
16.3.1 Mechanical strength. 68
16.3.2 Parts of insulating material necessary to retain parts of the earthing
circuit . 69
17 Creepage distances, clearances and distances through sealing compound . 72
18 Resistance of insulating material to abnormal heat and fire . 72
19 Resistance to tracking . 74
20 Resistance to corrosion . 75
21 Electromagnetic compatibility (EMC) . 75
Annex A (informative) Examples of enclosures and parts thereof . 76
Annex B (normative) Test for boxes and enclosures declared with IK code . 77
Annex AA (informative) Examples of connecting boxes/enclosures . 78
Annex BB (informative) Schematic presentation of connecting devices as a basis for
the definitions . 80
Annex CC (normative) Additional requirements for boxes and enclosures exposed to
direct sunlight . 81
Annex DD (normative) Additional requirements for connecting boxes and enclosures
having encapsulation capability . 82
DD.1 General . 82
DD.2 Applicability of this annex . 82
DD.3 General requirements . 82
Bibliography . 87

– 4 – IEC 60670-22:2024 EXV © IEC 2024
Figure 1 – Examples of membranes and grommets . 13
Figure 2 – Test piston dimensions. 21
Figure 3 – Demonstration of the non-penetration of the internal volume . 22
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 16 – Verification of fixing means for boxes and enclosures classified according
to 7.2.2.1 . 42
Figure 17 – Test of the force and measurement of the displacement . 44
Figure 18 – Volume measurement. 47
Figure 19 – Reference surfaces for boxes and enclosures . 52
Figure 20 – Test wall . 53
Figure 21 – Example of the protected volume . 55
Figure 22 – Apparatus for impact test at low temperature. 59
Figure 23 – Mounting block for flush-type boxes and enclosures in order to apply
blows on the rear surface . 61
Figure 24 – Sequence of blows for parts A, B, C, D, E, F and G . 64
Figure 25 – Test devices for load compression test for enclosures made of natural or

synthetic rubber or a mixture of both . 67
Figure 26 – Rigid crossbar . 69
Figure 101 – Single terminal device . 70
Figure 102 – Multiway terminal device . 71
Figure 27 – Diagrammatic representation of the glow-wire test . 74
Figure A.1 – Examples of enclosures and parts thereof. 76
Figure AA.1 – Four examples of connecting boxes/enclosures . 78
Figure AA.2 – Examples of cable joints . 79
Figure BB.1 – Schematic presentation . 80

Table 1 – Classification of boxes and enclosures . 17
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 . 56
Table 7 – Determination of parts A, B, C, D E, F and G . 61
Table 8 – Height of fall for impact test . 62
Table 101 – Relationship between rated connecting capacity and test current . 71
Table 102 – Creepage distances, clearances and distances through sealing compound . 72

– 6 – IEC 60670-22:2024 EXV © IEC 2024
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
BOXES AND ENCLOSURES FOR ELECTRICAL ACCESSORIES FOR
HOUSEHOLD AND SIMILAR FIXED ELECTRICAL INSTALLATIONS –

Part 22: Particular requirements for connecting boxes and enclosures

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
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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
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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 60670-22:2024 is displayed on a blue background.

IEC 60670-22 has been prepared by subcommittee 23B: Plugs, socket-outlets and switches, of
IEC technical committee 23: Electrical accessories. It is an International Standard.
This second edition cancels and replaces the first edition published in 2003 and
Amendment 1:2015. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) addition of cable joints as a new type of box with the related tests and requirements;
b) addition of tests and requirements for boxes and enclosures exposed to direct sunlight with
the related Annex CC;
c) addition of connecting boxes and enclosures having encapsulation capability as a new type
of boxes with the related tests, requirements and related Annex DD.
The text of this International Standard is based on the following documents:
Draft Report on voting
23B/1535/FDIS 23B/1553/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 connecting boxes and
enclosures.
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.

– 8 – IEC 60670-22:2024 EXV © IEC 2024
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.

BOXES AND ENCLOSURES FOR ELECTRICAL ACCESSORIES FOR
HOUSEHOLD AND SIMILAR FIXED ELECTRICAL INSTALLATIONS –

Part 22: Particular requirements for connecting boxes and enclosures

1 Scope
This part of IEC 60670 applies to boxes, enclosures and parts of enclosures (hereafter called
"boxes" and "enclosures") for electrical accessories with a rated voltage not exceeding
1 000 V AC and 1 500 V DC intended for household or similar fixed electrical installations,
either indoors or outdoors.
Boxes and enclosures complying with this document are suitable for use at ambient
temperatures not normally exceeding +40 °C, but their average over a period of 24 h does not
exceed +35 °C, with a lower limit of the ambient air temperature of −5 °C.
Other temperatures outside the above range can apply according to the classification of the
boxes and the enclosures.
This document applies to junction connecting boxes or tapping connecting boxes or both.
NOTE Unless otherwise stated, throughout the document the term "boxes" also applies to "enclosures".
This document is intended to apply to boxes and enclosures for electrical accessories within
the scope of IEC technical committee 23.
A box or an enclosure which is an integral part of an electrical accessory and provides protection
for that accessory against external influences (for example mechanical impact, ingress of solid
objects or water, etc.) is covered by the relevant standard for such an accessory.
This document gives test requirements for boxes and enclosures declared with IK code, see
Annex B (normative).
This document also applies to types of boxes and enclosures as modified in IEC 60670-21,
IEC 60670-22, IEC 60670-23, and IEC 60670-24.
This document does not apply to:
– ceiling roses;
– luminaire supporting couplers;
– boxes, enclosures and parts of enclosures specifically designed to be used for cable
trunking and ducting systems complying with IEC 61084 and which are not intended to be
installed outside of these systems.
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

– 10 – IEC 60670-22:2024 EXV © IEC 2024
IEC 60112:2020, Method for the determination of the proof and the comparative tracking indices
of solid insulating materials
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 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 60981:2019, Extra-heavy duty rigid steel conduits
IEC 60998 (all parts), Connecting devices for low-voltage circuits for household and similar
purposes
IEC 60999-1:1999, Connecting devices – Electrical copper conductors – Safety requirements
for screw-type and screwless-type clamping units – Part 1: General requirements and particular
2 2
requirements for clamping units for conductors from 0,2 mm up to 35 mm (included)
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
ISO 62:2008, Determination of water absorption
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.
– 12 – IEC 60670-22:2024 EXV © IEC 2024
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.]
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 accessory
Note 1 to entry: See Figure 1.
3.17
composite material
combination of metal and insulating material
3.18
spout
hub
open entry of a box permitting the insertion and containment of a conduit
3.19
cable retention
ability to limit the displacement of a fitted cable against pull forces

– 14 – IEC 60670-22:2024 EXV © IEC 2024
3.20
cable anchorage
ability to limit the displacement of a fitted flexible cable against pull and push forces and torques
3.21
blanking-plug
component used to close an open inlet or an open knock-out
3.22
U
n
rated voltage
voltage assigned by the manufacturer for a specific operating condition of the box or enclosure
[SOURCE: IEC 60050-442:1998, 442-01-03, modified – The symbol has been added as a term,
the domain "(of accessories)" has been deleted; in the definition, "accessory" has been replaced
with "box or enclosure".]
3.101
connecting box
junction box
box allowing connection of conductors
3.101.1
junction connecting box
connecting box allowing connection of one or more junctions
3.101.2
tapping connecting box
connecting box allowing connection of one or more taps from one or more main conductors
Note 1 to entry: Connecting boxes according to 3.101.1 and 3.101.2 may be combined.
3.102
connecting box with integrated clamping units
box allowing connection of conductors in which clamping units are permanently retained as an
integrated part of the box (see Annex AA)
Note 1 to entry: For example, see Figure AA.1
3.103
connecting box with incorporated terminals or connecting devices
box allowing connection of conductors with detachable terminals or connecting devices retained
within the box by mechanical means (see Annex AA)
Note 1 to entry: For example, see Figure AA.1
3.104
connecting box with provisions for subsequent incorporation of terminals or
connecting devices
box allowing connection of conductors with provisions for incorporating terminals or connecting
devices to be retained within the box by mechanical means (see Annex AA)
Note 1 to entry: For example, see Figure AA.1
3.105
connecting box for floating terminals or connecting devices
box allowing connection of conductors intended to accommodate terminals or connecting
devices but without provision to retain them (see Annex AA)
Note 1 to entry: For example, see Figure AA.1

3.106
rated connecting capacity
cross-sectional area of the largest conductors as declared by the manufacturer
3.107
terminal
conductive part of one pole comprising one or more clamping unit(s) and insulation if necessary
3.108
clamping unit
part(s) of a terminal necessary for the mechanical clamping and the electrical connection of the
conductor(s) including the parts which are necessary to ensure correct contact pressure
3.109
connecting device
device for the electrical connection of two or more conductors comprising one or more terminals
and if necessary, insulation and/or ancillary parts
Note 1 to entry: For a schematic representation of connecting devices see Figure BB.1 of Annex BB.
3.110
cable joint
connecting enclosure provided with cable glands (or other means) having cable anchorage
function, intended to make a connection between two or more insulated cables to form a
continuous circuit in the fixed installation
Note 1 to entry: For example, see Figure AA.2
3.111
junction
connection between two or more conductor ends
3.112
tapping
connection of a conductor end (called "tapped conductor") on any point of another conductor
(called "main conductor")
Note 1 to entry: The main conductor is not interrupted.
3.113
CBEC
connecting box having encapsulation capability
box allowing the connection of conductors and intended to encapsulate the clamping units,
terminals or connecting devices with an encapsulating compound
3.114
encapsulating compound
material to encapsulate the clamping units, terminals or connecting devices in CBEC
4 General requirements
Boxes and enclosures shall be so designed and constructed that, in normal use, their
performance is reliable, and safety is achieved by reducing risk to a tolerable level, as defined
in ISO/IEC Guide 51.
Connecting devices incorporated in connecting boxes shall comply with the requirements of the
IEC 60998 series; integrated clamping units shall comply with the requirements of
IEC 60999-1:1999.
– 16 – IEC 60670-22:2024 EXV © IEC 2024
NOTE 101 In the following countries terminal blocks according to IEC 60947-7-1 and IEC 60947-7-2 are allowed to
be incorporated in connecting boxes: DE.
Compliance is checked by meeting all the relevant requirements and tests specified.
5 General remarks on tests
5.1 Test conditions and number of samples
Tests according to this document are type tests.
Unless otherwise specified in this document, boxes and enclosures are tested as delivered.
Accessories complying with other standards are not tested again.
Tests on boxes and enclosures of insulating material shall be performed after a preconditioning
period of at least 48 h at ambient temperature between +15 °C and +35 °C and relative air
humidity between 45 % and 85 %.
NOTE For some materials a longer preconditioning period can be requested by the manufacturer.
Unless otherwise specified, the tests are carried out in the order of the clauses, at an ambient
temperature between +15 °C and +35 °C on a set of three specimens.
It is recommended that the tests are carried out at an ambient temperature of (20 ± 5) °C.
5.2 Compliance general requirement
The specimens are submitted to all the relevant tests and the requirements are satisfied if all
the applicable tests are deemed to have been passed.
If one of the specimens does not satisfy a test due to an assembly or a manufacturing fault,
that test and any preceding ones which may have influenced the results of the test shall be
repeated and also the tests which follow shall be carried out in the required sequence on
another full set of specimens, all of which shall comply with the requirements.
NOTE When submitting the first set of specimens, the applicant can also submit the additional set of specimens
which can be necessary, if one specimen fails. The testing station will then, without further request, test the additional
set of specimens and will only reject if a further failure occurs. If the additional set of specimens is not submitted at
the same time, the failure of one specimen will entail rejection.
In this document the term "instructions" is understood to mean manufacturer's instructions.
Connecting boxes with provision for subsequent incorporation of clamping units are tested with
the clamping units recommended by the manufacturer.
Connecting devices that are in accordance with the IEC 60998 series are not required to be
tested again.
NOTE 101 In the following countries terminal blocks according to IEC 60947-7-1 and IEC 60947-7-2 are not
required to be tested again: DE.
NOTE 102 In the following countries connecting boxes shall be tested either:
• with their incorporated terminals or connecting devices or
• with the terminals or connecting devices recommended by the manufacturer for connecting boxes with provision
for subsequent incorporation of terminals or connecting devices: UK.

6 Ratings
6.1 The preferred values of the rated voltage of the integrated or incorporated connecting
devices are 125 V, 250 V, 300 V, 400 V, 500 V, 600 V, 690 V, 800 V, 1 000 V AC and
1 500 V DC.
2 2 2 2
6.2 The standard rated connecting capacities are 0,2 mm , 0,34 mm , 0,5 mm , 0,75 mm ,
2 2 2 2 2 2 2 2 2
1 mm , 1,5 mm , 2,5 mm , 4 mm , 6 mm , 10 mm , 16 mm , 2
...

IEC 60670-22 ®
Edition 2.0 2024-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Boxes and enclosures for electrical accessories for household and similar fixed
electrical installations –
Part 22: Particular requirements for connecting boxes and enclosures

Boîtes et enveloppes pour appareillage électrique pour installations électriques
fixes pour usages domestiques et analogues –
Partie 22: Exigences particulières pour les boîtes et enveloppes de connexion
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IEC 60670-22 ®
Edition 2.0 2024-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Boxes and enclosures for electrical accessories for household and similar fixed

electrical installations –
Part 22: Particular requirements for connecting boxes and enclosures

Boîtes et enveloppes pour appareillage électrique pour installations électriques

fixes pour usages domestiques et analogues –

Partie 22: Exigences particulières pour les boîtes et enveloppes de connexion

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.120.10  ISBN 978-2-8327-0046-4

– 2 – IEC 60670-22:2024 © IEC 2024
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 General requirements . 7
5 General remarks on tests . 7
6 Ratings . 8
7 Classification . 8
8 Marking . 9
9 Dimensions. 9
10 Protection against electric shock . 9
11 Provision for earthing . 9
12 Construction . 10
13 Resistance to ageing, protection against ingress of solid objects and against
harmful ingress of water . 11
14 Insulation resistance and electric strength . 11
15 Mechanical strength . 11
16 Resistance to heat . 12
17 Creepage distances, clearances and distances through sealing compound . 14
18 Resistance of insulating material to abnormal heat and fire . 15
19 Resistance to tracking . 15
20 Resistance to corrosion . 15
21 Electromagnetic compatibility (EMC) . 15
Annex AA (informative) Examples of connecting boxes/enclosures . 16
Annex BB (informative) Schematic presentation of connecting devices as a basis for
the definitions . 18
Annex CC (normative) Additional requirements for boxes and enclosures exposed to
direct sunlight . 19
Annex DD (normative) Additional requirements for connecting boxes and enclosures
having encapsulation capability . 20
Bibliography . 25

Figure 101 – Single terminal device . 13
Figure 102 – Multiway terminal device . 13
Figure AA.1 – Four examples of connecting boxes/enclosures . 16
Figure AA.2 – Examples of cable joints . 17
Figure BB.1 – Schematic presentation . 18

Table 101 – Relationship between rated connecting capacity and test current . 14
Table 102 – Creepage distances, clearances and distances through sealing compound . 14

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
BOXES AND ENCLOSURES FOR ELECTRICAL ACCESSORIES FOR
HOUSEHOLD AND SIMILAR FIXED ELECTRICAL INSTALLATIONS –

Part 22: Particular requirements for connecting boxes and enclosures

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.
IEC 60670-22 has been prepared by subcommittee 23B: Plugs, socket-outlets and switches, of
IEC technical committee 23: Electrical accessories. It is an International Standard.
This second edition cancels and replaces the first edition published in 2003 and
Amendment 1:2015. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) addition of cable joints as a new type of box with the related tests and requirements;
b) addition of tests and requirements for boxes and enclosures exposed to direct sunlight with
the related Annex CC;
– 4 – IEC 60670-22:2024 © IEC 2024
c) addition of connecting boxes and enclosures having encapsulation capability as a new type
of boxes with the related tests, requirements and related Annex DD.
The text of this International Standard is based on the following documents:
Draft Report on voting
23B/1535/FDIS 23B/1553/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 connecting boxes and
enclosures.
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.

BOXES AND ENCLOSURES FOR ELECTRICAL ACCESSORIES FOR
HOUSEHOLD AND SIMILAR FIXED ELECTRICAL INSTALLATIONS –

Part 22: Particular requirements for connecting boxes and enclosures

1 Scope
Clause 1 of IEC 60670-1:2024 applies with the following addition:
Add the following after the third paragraph:
This document applies to junction connecting boxes or tapping connecting boxes or both.
NOTE Unless otherwise stated, throughout the document the term "boxes" also applies to "enclosures".
2 Normative references
Clause 2 of IEC 60670-1:2024 applies with the following additions:
IEC 60998 (all parts), Connecting devices for low-voltage circuits for household and similar
purposes
IEC 60999-1:1999, Connecting devices – Electrical copper conductors – Safety requirements
for screw-type and screwless-type clamping units – Part 1: General requirements and particular
2 2
requirements for clamping units for conductors from 0,2 mm up to 35 mm (included)
ISO 62:2008, Determination of water absorption
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
Clause 3 of IEC 60670-1:2024 applies with the following additions:
3.101
connecting box
junction box
box allowing connection of conductors
3.101.1
junction connecting box
connecting box allowing connection of one or more junctions

– 6 – IEC 60670-22:2024 © IEC 2024
3.101.2
tapping connecting box
connecting box allowing connection of one or more taps from one or more main conductors
Note 1 to entry: Connecting boxes according to 3.101.1 and 3.101.2 may be combined.
3.102
connecting box with integrated clamping units
box allowing connection of conductors in which clamping units are permanently retained as an
integrated part of the box (see Annex AA)
Note 1 to entry: For example, see Figure AA.1
3.103
connecting box with incorporated terminals or connecting devices
box allowing connection of conductors with detachable terminals or connecting devices retained
within the box by mechanical means (see Annex AA)
Note 1 to entry: For example, see Figure AA.1
3.104
connecting box with provisions for subsequent incorporation of terminals or
connecting devices
box allowing connection of conductors with provisions for incorporating terminals or connecting
devices to be retained within the box by mechanical means (see Annex AA)
Note 1 to entry: For example, see Figure AA.1
3.105
connecting box for floating terminals or connecting devices
box allowing connection of conductors intended to accommodate terminals or connecting
devices but without provision to retain them (see Annex AA)
Note 1 to entry: For example, see Figure AA.1
3.106
rated connecting capacity
cross-sectional area of the largest conductors as declared by the manufacturer
3.107
terminal
conductive part of one pole comprising one or more clamping unit(s) and insulation if necessary
3.108
clamping unit
part(s) of a terminal necessary for the mechanical clamping and the electrical connection of the
conductor(s) including the parts which are necessary to ensure correct contact pressure
3.109
connecting device
device for the electrical connection of two or more conductors comprising one or more terminals
and if necessary, insulation and/or ancillary parts
Note 1 to entry: For a schematic representation of connecting devices see Figure BB.1 of Annex BB.

3.110
cable joint
connecting enclosure provided with cable glands (or other means) having cable anchorage
function, intended to make a connection between two or more insulated cables to form a
continuous circuit in the fixed installation
Note 1 to entry: For example, see Figure AA.2
3.111
junction
connection between two or more conductor ends
3.112
tapping
connection of a conductor end (called "tapped conductor") on any point of another conductor
(called "main conductor")
Note 1 to entry: The main conductor is not interrupted.
3.113
CBEC
connecting box having encapsulation capability
box allowing the connection of conductors and intended to encapsulate the clamping units,
terminals or connecting devices with an encapsulating compound
3.114
encapsulating compound
material to encapsulate the clamping units, terminals or connecting devices in CBEC
4 General requirements
Clause 4 of IEC 60670-1:2024 is applicable with the following addition:
Connecting devices incorporated in connecting boxes shall comply with the requirements of the
IEC 60998 series; integrated clamping units shall comply with the requirements of
IEC 60999-1:1999.
NOTE 101 In the following countries terminal blocks according to IEC 60947-7-1 and IEC 60947-7-2 are allowed to
be incorporated in connecting boxes: DE.
5 General remarks on tests
Clause 5 of IEC 60670-1:2024 applies with the following addition:
5.2 Add at the end of Subclause 5.2:
Connecting boxes with provision for subsequent incorporation of clamping units are tested with
the clamping units recommended by the manufacturer.
Connecting devices that are in accordance with the IEC 60998 series are not required to be
tested again.
NOTE 101 In the following countries terminal blocks according to IEC 60947-7-1 and IEC 60947-7-2 are not
required to be tested again: DE.

– 8 – IEC 60670-22:2024 © IEC 2024
NOTE 102 In the following countries connecting boxes shall be tested either:
• with their incorporated terminals or connecting devices or
• with the terminals or connecting devices recommended by the manufacturer for connecting boxes with provision
for subsequent incorporation of terminals or connecting devices: UK.
6 Ratings
Clause 6 of IEC 60670-1:2024 is replaced by the following:
6.1 The preferred values of the rated voltage of the integrated or incorporated connecting
devices are 125 V, 250 V, 300 V, 400 V, 500 V, 600 V, 690 V, 800 V, 1 000 V AC and
1 500 V DC.
2 2 2 2
6.2 The standard rated connecting capacities are 0,2 mm , 0,34 mm , 0,5 mm , 0,75 mm ,
2 2 2 2 2 2 2 2 2
1 mm , 1,5 mm , 2,5 mm , 4 mm , 6 mm , 10 mm , 16 mm , 25 mm , 35 mm .
NOTE 101 For the time being, designation by wire gauge may be used in some countries (for example AWG in US
and CA), instead of the cross-sectional areas expressed in mm .
NOTE 102 The approximate relation between mm and AWG sizes is given in Annex A of IEC 60999-1:1999.
NOTE 103 In UK, a standard connecting capacity of 1,25 mm is used.
2 2 2 2 2 2
NOTE 104 In Japan, standard connecting capacities of 0,9 mm ,1,25 mm , 2,0 mm , 3,5 mm , 5,5 mm , 8 mm ,
2 2
, 22 mm are used.
14 mm
7 Classification
Clause 7 of IEC 60670-1:2024 applies with the following addition:
Add the following to Table 1:
7.101 The method of fixing the 7.101.1 With integrated clamping units
terminals or connecting devices
7.101.2 With incorporated terminals or
in the connecting box
connecting devices
7.101.3 With provisions for subsequent
incorporation of terminals or connecting
devices
7.101.4 Without fixing (for floating
terminals or connecting devices)
7.102 The capability to 7.102.1 Without the capability to
encapsulate the clamping units, encapsulate the clamping units,
terminals or connecting devices terminals or connecting devices
7.102.2 With the capability to
encapsulate the clamping units,
terminals or connecting devices (see
Annex DD)
8 Marking
Clause 8 of IEC 60670-1:2024 applies with the following additions:
8.1 General
Add the following after list item k):
l) rated voltage for boxes with integrated or incorporated terminals or connecting devices;
m) rated connecting capacity (see Note 101);
n) maximum number of conductors to be placed in the box (see Note 101);
The information in items m) and n) is optional for boxes classified according to 7.101.4.
The manufacturer may mark or declare more than one combination of m) and n).
NOTE 101 In the following countries this information in Subclause 8.1 is mandatory for boxes classified according
to 7.101.4: DE and SE.
o) boxes and enclosures classified according to 7.101.1 or 7.101.2 shall be marked with an
appropriate rated current which does not exceed the test current given in Table 101.
NOTE 102 In the following country the marking of the rated current is optional: DE
Add the following subclauses:
8.101 Symbols
When symbols are used they shall be as follows:
Volt . V
Rated connecting capacity . mm or  or AWG
8.102 Instructions for cable joints
Information shall be given in the manufacturer's instructions that cable joints are not intended
for portable use or for being buried underground. These instructions are not required to be
provided with the product.
9 Dimensions
Clause 9 of IEC 60670-1:2024 applies.
10 Protection against electric shock
Clause 10 of IEC 60670-1:2024 applies.
11 Provision for earthing
Clause 11 of IEC 60670-1:2024 applies.

– 10 – IEC 60670-22:2024 © IEC 2024
12 Construction
Clause 12 of IEC 60670-1:2024 applies with the following modifications:
12.2.1 Add the following after the first paragraph:
In connecting boxes where the fixing means of covers or cover-plates serve also to fix the
connecting device, the fixing means shall maintain the connecting device in the correct position
after removal of the cover or cover-plate.
Compliance is checked by inspection.
12.3 Drain holes
Add after the last paragraph:
This Subclause 12.3 does not apply for cable joints.
12.7 Boxes and enclosures with a cable anchorage(s)
Subclause 12.7 of IEC 60670-1:2024 applies with the following addition before Figure 12:
For the purpose of cable joints, the test of 12.7 is repeated with rigid cables as specified in the
instructions.
Add the following subclauses:
12.101 Connecting boxes shall have adequate space to allow the correct connection of
conductors which are specified in the relevant clauses of the particular requirements of
IEC 60998-2-1, IEC 60998-2-2, IEC 60998-2-3, and IEC 60998-2-4 concerning the number and
cross-sectional area of the conductors.
For connecting boxes classified according to 7.101.1, 7.101.2 and 7.101.3, compliance is
checked by fitting the maximum number of conductors of the maximum cross-sectional area if
that is the worst-case combination. If not, the most unfavourable combination shall be checked.
This test shall be carried out in conjunction with that of 12.102.
For boxes classified according to 7.101.4 compliance is checked by fitting the maximum number
of conductors and connecting devices as declared in 8.1 m) and 8.1 n). The test is carried out
only if m) and n) of 8.1 are marked or declared.
12.102 Retention means for terminals or connecting devices shall withstand the mechanical
stresses occurring during installation and normal use.
Compliance is checked by connecting conductors in accordance with IEC 60998-2-1,
IEC 60998-2-2, IEC 60998-2-3 or IEC 60998-2-4 as applicable for the type of the connecting
device used.
After the test there shall be no harmful deformation, cracks or similar damage which would lead
to non-compliance with this document.
12.103 Connecting boxes classified according to 7.101.1, 7.101.2 and 7.101.3 shall comply
with the temperature rise requirements of 16.102.

12.104 Cable joints shall be classified according to 7.4.2, having means for cable anchorage,
and provided with cable glands or other means as defined by the manufacturer.
Compliance is checked by inspection and by the test of 12.7.
NOTE IEC 62444 is applicable to cable glands for electrical installations.
13 Resistance to ageing, protection against ingress of solid objects and against
harmful ingress of water
Clause 13 of IEC 60670-1:2024 applies with the following addition:
13.3.3 Replace the last paragraph by the following:
The specimens, except connecting boxes classified according to 7.101.4, shall withstand an
electric strength test specified in 14.2 which shall be started within 5 min of the completion of
the test according to this Subclause 13.3.3.
14 Insulation resistance and electric strength
Clause 14 of IEC 60670-1:2024 applies with the following addition:
Add the following:
14.2.101 For boxes with integrated or incorporated terminals or connecting devices, the
measurements are made consecutively as indicated below.
Each clamping unit of a connecting device shall be tested when connected with conductors of
the smallest and tested when connected with connectors of the largest cross-sectional area.
The insulation resistance is then measured with a DC voltage of approximately 500 V applied,
the measurement being made 1 min after application of the voltage:
a) between all clamping units connected together and the body for connecting devices without
fixing means or between all clamping units connected together and the mounting base for
connecting devices with fixing means;
b) between each clamping unit and all others connected to the body for connecting devices
without fixing means or between each clamping unit and all others connected to the
mounting base for connecting devices with fixing means.
The metal foil is applied in such a way that the sealing compound, if any, is effectively tested.
The insulation resistance shall be not less than 5 MΩ.
15 Mechanical strength
Clause 15 of IEC 60670-1:2024 applies with the following modifications:
15.2 Impact test at low temperature
Replace the sixth paragraph with the following paragraph:
Damage to the finish, small dents which do not reduce creepage distances or clearances below
the value specified in Table 102 and small chips which do not adversely affect the protection
against electric shock or harmful ingress of water are disregarded.

– 12 – IEC 60670-22:2024 © IEC 2024
Add the following subclause:
15.101 Additional requirements for boxes and enclosures exposed to direct sunlight
When boxes or enclosures are declared to be resistant to UV radiation, they are tested
according to Annex CC of this document.
This test applies only to boxes and enclosures classified according to 7.1.1, 7.1.3 and 7.1.4.
16 Resistance to heat
Clause 16 of IEC 60670-1:2024 applies with the following addition:
Add the following subclauses:
16.101 Resistance to heat of connecting devices
16.101.1 Connecting devices having parts of insulating material shall be sufficiently resistant
to heat.
Compliance is checked by the test of 16.101.2 to 16.101.4 performed on three extra specimens.
16.101.2 The specimens or portions of the specimens are kept for 1 h in a heating cabinet at
a temperature of (85 ± 2) °C.
During the test they shall not undergo any change impairing their further use and sealing
compound if any, shall not flow to such an extent that live parts are exposed.
After the test and after the specimens have been allowed to cool to approximately ambient
temperature, there shall be no access to live parts which are normally not accessible when the
specimens are mounted as in normal use, even if the test probe B of IEC 61032 is applied with
a force not exceeding 5 N.
After the test, markings shall still be legible.
16.101.3 Parts of the insulating material not necessary to retain current carrying parts and
parts of the earthing circuit in position, even though they are in contact with them, are subjected
to a ball-pressure test as described in IEC 60670-1:2024, Clause 16 but at a temperature of (70
± 2) °C or (40 ± 2) °C, plus the highest temperature rise determined for the relevant part during
the test of 16.102.5, whichever is the higher.
16.101.4 Parts of the insulating material necessary to retain current carrying parts and parts
of the earthing circuit in position are subjected to a ball pressure test in a heating cabinet at
a temperature of (125 ± 2) °C.
16.102 Resistance to heat of connecting devices integrated in connecting boxes
16.102.1 Connecting devices integrated in connecting boxes shall be so constructed that the
temperature rise in normal use does not exceed the value specified in 16.102.5.
Compliance is checked by the tests of 16.102.2 to 16.102.3.
NOTE 101 In the following countries connecting devices integrated or incorporated in connecting boxes shall be so
constructed that the temperature rise in normal use does not exceed the values specified in 16.102.5. Compliance
is checked by the tests of 16.102.2 to 16.102.4: UK.

16.102.2 Connecting devices with a single terminal (see Figure 101) having one or more
clamping units shall be connected to conductors in the intended manner and under the most
unfavourable conditions.
Figure 101 – Single terminal device
16.102.3 For multiway terminal devices a maximum of three adjacent terminals are connected
in series. If single pole connecting devices are designed to be mounted side by side, three
devices are placed in the intended manner and connected together (see Figure 102).

Figure 102 – Multiway terminal device
16.102.4 The connections are made with new rigid or flexible conductors of the largest cross-
sectional area appropriate to the clamping units, the clamping units being connected according
to the specifications of the relevant part of IEC 60998.
Conductor length shall be 1 m for a cross-sectional area up to and including 10 mm and 2 m
for a cross-sectional area above 10 mm . Conductor length may be reduced in agreement with
the manufacturer.
16.102.5 Temperature rise measurements are made when the device under test has reached
thermal equilibrium. It is generally accepted that the temperature is stable when the temperature
of the part under test does not increase by more than 1 K/h. During the test the devices are
loaded with an alternating current having the value shown in Table 101 for the corresponding
rated connecting capacity.
The temperature is determined by means of colour changing indicators or thermocouples, so
chosen and positioned that they have a negligible effect on the temperature being determined
(e.g. on the metallic part in contact with the conductor).

– 14 – IEC 60670-22:2024 © IEC 2024
Table 101 – Relationship between rated connecting capacity and test current
Rated connecting capacity Test current
mm A
0,2 4
0,34 5
0,5 6
0,75 9
1 13,5
1,5 17,5
2,5 24
4 32
6 41
10 57
16 76
25 101
35 125
The temperature rise of current-carrying parts of the clamping unit shall not exceed 45 K, it
being understood that in the case of an insulated device the temperature rise of the conductor
shall be measured as close as possible to the clamping unit.
For the purpose of the test of 16.101.3, the temperature rise of external parts of insulating
material not necessary to retain current-carrying parts and parts of the earthing circuit in
position, even though they are in contact with them, is also determined.
17 Creepage distances, clearances and distances through sealing compound
Creepage distances, clearances and distances through sealing compound shall not be less than
the value shown in Table 102.
This test does not apply to connecting boxes for floating terminals or connecting devices
classified according to 7.101.4.
Table 102 – Creepage distances, clearances and distances through sealing compound
Creepage distance, clearance and
Rated voltage
distance through sealing compound
V mm
≤ 130 1,5
> 130 and ≤ 250 3,0
> 250 and ≤ 450 4,0
> 450 and ≤ 750 6,0
> 750 8,0
Compliance is checked by measurement between the following parts:
Creepage distances and clearances:
– between live parts of different polarity;
– between live parts and
• metal covers and boxes without insulating lining;
• the surface on which the box is mounted.
Distances through sealing compound:
– between live parts covered with sealing compound and the surface on which the box is
mounted.
For multi-way terminal devices and terminals without fixing means but with protection, distances
are measured between live parts and any opening which represents the closest point liable to
touch any other part when the terminal is fitted with conductors having the largest
cross-sectional area.
In cases where various terminals or connecting devices may be mounted in the box, the most
unfavourable combinations shall be tested.
18 Resistance of insulating material to abnormal heat and fire
Clause 18 of IEC 60670-1:2024 applies.
19 Resistance to tracking
Clause 19 of IEC 60670-1:2024 applies.
20 Resistance to corrosion
Clause 20 of IEC 60670-1:2024 applies.
21 Electromagnetic compatibility (EMC)
Clause 21 of IEC 60670-1:2024 applies.

– 16 – IEC 60670-22:2024 © IEC 2024
Annex AA
(informative)
Examples of connecting boxes/enclosures
a) Connecting box with integrated clamping units
according to 7.101.1
b) Connecting box with incorporated terminals or
connecting devices according to 7.101.2

c) Connecting box with provisions for subsequent
incorporation of terminals or connecting devices
according to 7.101.3
d) Connecting box without fixing (for floating
terminals or connecting devices) according to
7.101.4
Figure AA.1 – Four examples of connecting boxes/enclosures

Key
1) Cable
2) Cable gland
3) Connecting device
4) Box
Figure AA.2 – Examples of cable joints

– 18 – IEC 60670-22:2024 © IEC 2024
Annex BB
(informative)
Schematic presentation of connecting devices
as a basis for the definitions

Figure BB.1 – Schematic presentation

Annex CC
(normative)
Additional requirements for boxes and
enclosures exposed to direct sunlight
Boxes and enclosures declared to be resistant to UV radiation shall comply with the following
tests.
The tests shall be made on six test specimens of standard size according to ISO 178:2019 and
on six test specimens of standard size according to ISO 179-1 exposed for 500 h to Xenon-arc,
Method A, Cycle 1 in accordance with ISO 4892-2. The specimens shall be mounted in the UV
apparatus in an appropriate manner:
• suitable for both the product to be tested and the test equipment and,
• so that the samples do not touch each other.
Compliance is checked by verification that the flexural strength (according to ISO 178) and
Charpy impact (according to ISO 179-1) of synthetic materials have 70 % minimum retention.
For the test carried out in accordance with ISO 178, the surface of the specimens exposed to
UV shall be turned face down and the pressure applied to the non-exposed surface.
For the test carried out in accordance with ISO 179-1 no notch shall be cut into the specimens
and the impact shall be applied to the exposed surface. For materials whose impact bending
strength cannot be determined prior to exposure because no rupture has occurred, not more
than three of the exposed test specimens shall be allowed to break.
The specimens shall not show cracks or deterioration visible to normal or corrected vision
without additional magnification.
These tests are not required to be carried out if the manufacturer can provide data from the
material supplier to demonstrate that materials of the same thickness or thinner comply with
this requirement.
– 20 – IEC 60670-22:2024 © IEC 2024
Annex DD
(normative)
Additional requirements for connecting boxes and
enclosures having encapsulation capability
DD.1 General
Under certain ambient conditions, water condensation inside boxes or enclosures and the entry
of water and solid objects can lead to insulation faults and failure of internally connected
circuits. Encapsulation with a compound is intended to prevent this from occurring.
DD.2 Applicability of this annex
This Annex DD applies to boxes and enclosures having the capability to encapsulate the
clamping units, terminals or connecting devices and their connections with conductors
according to classification 7.102.2.
These boxes and enclosures are intended to prevent the formation of water condensation and
the entry of water and solid objects.
NOTE Boxes and enclosures according to this Annex DD can be used for example in the ground, high humidity
areas, flooded areas (temporarily submerged) and ground-level installation (rain, snow).
The use of connecting boxes having encapsulation capability (CBEC) buried in the ground is
limited to use at a reduced depth and where they are not subjected to significant compression
forces due to the passage of vehicles, people or similar case.
This Annex DD does not apply to
– cable accessories (for example products covered by EN 50393);
– products buried in the ground with traffic loads;
– other inaccessible, encapsulated connections.
NOTE The following modifications to this document are applicable to connecting boxes and enclosures having
encapsulation capability. The clause numbers in that follow refer to the clause numbers in the main body text of this
document that are modified.
DD.3 General requirements
Add the following at the end of the clause:
CBEC shall be used with connecting devices and encapsulating compound according to the
manufacturer's instructions.
5.1 Test conditions and number of samples
Add the following at the
...