IEC 60670-22:2024

IEC 60670-22 ®
Edition 2.0 2024-12
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
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
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
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 978-2-8327-0113-3

– 2 – IEC 60670-22:2024 RLV © IEC 2024
CONTENTS
FOREWORD . 3
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 General requirements . 8
5 General notes remarks on tests . 8
6 Ratings . 9
7 Classification . 9
8 Marking . 9
9 Dimensions. 10
10 Protection against electric shock . 11
11 Provision for earthing . 11
12 Construction . 11
13 Resistance to ageing, protection against ingress of solid objects and against
harmful ingress of water . 12
14 Insulation resistance and electric strength . 12
15 Mechanical strength . 13
16 Resistance to heat . 13
17 Creepage distances, clearances and distances through sealing compound . 15
18 Resistance of insulating material to abnormal heat and fire . 16
19 Resistance to tracking . 16
20 Resistance to corrosion . 16
21 Electromagnetic compatibility (EMC) . 16
Annex AA (informative) Examples of connecting boxes/enclosures . 17
Annex BB (informative) Schematic presentation of connecting devices as a basis for
the definitions . 19
Annex CC (normative) Additional requirements for boxes and enclosures exposed to
direct sunlight . 20
Annex DD (normative) Additional requirements for connecting boxes and enclosures
having encapsulation capability . 21
Bibliography . 26

Figure 101 – Single terminal device . 14
Figure 102 – Multiway terminal device . 14
Figure AA.1 – Four examples of connecting boxes/enclosures . 17
Figure AA.2 – Examples of cable joints . 18
Figure BB.1 – Schematic presentation . 19

Table 101 – Relationship between rated connecting capacity and test current . 15
Table 102 – Creepage distances, clearances and distances through sealing compound . 15

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
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6) All users should ensure that they have the latest edition of this publication.
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) 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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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 redline version of the official IEC Standard allows the user to identify the changes
made to the previous edition IEC 60670-22:2003+AMD1:2015 CSV. A vertical bar appears
in the margin wherever a change has been made. Additions are in green text, deletions
are in strikethrough red text.

– 4 – IEC 60670-22:2024 RLV © IEC 2024
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.

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.

– 6 – IEC 60670-22:2024 RLV © IEC 2024
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 fourth third paragraph:
This document applies to junction connecting boxes for junction(s) and/ or tapping(s) 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 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

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.
3.101.3
cord outlet connecting box
connecting box allowing one or more connections to be made between a fixed installation and
a flexible cable
3.102
connecting box with integrated clamping units
connecting box 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
connecting box 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
lowing connection of conductors with provisions for incorporating
connecting box box al
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
connecting box 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.

– 8 – IEC 60670-22:2024 RLV © IEC 2024
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 the
IEC 60999 series 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 notes 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 need are not required to
be tested again.
NOTE 1101 In the following countries terminal blocks according to IEC 60947-7-1 and IEC 60947-7-2 need are not
required to be tested again: DE.

NOTE 2102 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 1 101 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 2 102 The approximate relation between mm and AWG sizes is given in Annex A of IEC 60999-1:1999.
NOTE 3 103 In UK, a standard connecting capacity of 1,25 mm is used.
2 2 2 2 2 2
NOTE 4 104 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
14 mm , 22 mm are used.
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 after j):
– 10 – IEC 60670-22:2024 RLV © IEC 2024
k) rated insulation voltage for boxes with integrated or incorporated terminals or connecting
devices (see note 1),
l) rated connecting capacity (see notes 1 and 2),
m) maximum number of conductors to be placed in the box (see notes 1 and 2).
The information l) and m) are optional for boxes classified according to 7.101.4.
n) 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 1 In the case of:
– integrated clamping units, k), l) and n) should be marked on the boxes,
– incorporated terminals or connecting devices, the marking k), l) and n) if marked on the box or on the
incorporated terminals or connecting devices, should be visible during installation,
– empty boxes for floating terminals or connecting devices classified according to 7.101.4, the marking l) and m),
if marked on the box, should be visible during installation.
NOTE 2 The manufacturer may mark or declare more than one combination of l) and m). This information is
mandatory for boxes classified according to 7.101.4 in the following countries: DE and SE.
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.
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, it 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 Parts 2
of IEC 60998 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 the test is made only if l) and m) of 8.1 are marked or
declared.
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.

– 12 – IEC 60670-22:2024 RLV © IEC 2024
Compliance is checked by connecting conductors in accordance with the relevant Part(s) 2 of
IEC 60998 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 alternatively 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 amendment 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.
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 16.101.12 to 16.101.34 performed on three extra
specimens.
16.101.12 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.
16.101.23 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 16.102.45, whichever is the higher.

– 14 – IEC 60670-22:2024 RLV © IEC 2024
16.101.34 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 16.102.45.
Compliance is checked by the tests of 16.102.12 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 16.102.45. Compliance
is checked by the tests of 16.102.12 to 16.102.34: UK.
16.102.12 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
16.102.23 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
16.102.34 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.
16.102.45 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).
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.
NOTE For the purpose of the test of 16.101.23, 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
– 16 – IEC 60670-22:2024 RLV © IEC 2024
> 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.

Annex AA
(informative)
Examples of connecting boxes/enclosures
a) EnclosuresConnecting box with integrated
clamping units according to 7.101.1

b) EnclosuresConnecting box with incorporated
terminals or connecting devices according to
7.101.2
c) EnclosuresConnecting box with provisions for
subsequent incorporation of terminals or
connecting devices according to 7.101.3

d) EnclosuresConnecting box without fixing (for
floating terminals or connecting devices) according
to 7.101.4
Figure AA.1 – Four examples of connecting boxes/enclosures

– 18 – IEC 60670-22:2024 RLV © IEC 2024

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

Annex BB
(informative)
Schematic presentation of connecting devices
as a basis for the definitions

Figure BB.1 – Schematic presentation

– 20 – IEC 60670-22:2024 RLV © IEC 2024
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.
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 end of the subclause:
CBEC shall be tested when mounted, assembled and wired as for normal use according to the
manufacturer's instructions.
CBECs are tested filled with encapsulating compound unless otherwise specified in this
Annex DD.
– 22 – IEC 60670-22:2024 RLV © IEC 2024
8 Marking
Modification:
8.1 General
Add the following at the end of the subclause, after NOTE 103:
The encapsulating compound to be used shall be specified in the manufacturer's instructions.
If different IP codes are declared for a CBEC when it is filled with encapsulating compound or
without encapsulating compound, both IP codes shall be marked so that it is clear to which
situation each IP code corresponds.
8.101 Symbols
Add the following at the end of the subclause:
IP code when encapsulated
(IEC 60417-6458 (2023-11))
NOTE 101 In the IP code
...