IEC 60670-21:2024

IEC 60670-21 ®
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 21: Particular requirements for boxes and enclosures with provision for
suspension means
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IEC 60670-21 ®
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 21: Particular requirements for boxes and enclosures with provision for
suspension means
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.120.99 ISBN 978-2-8327-0111-9

– 2 – IEC 60670-21:2024 RLV © IEC 2024
CONTENTS
FOREWORD . 3
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 General requirements . 7
5 General notes remarks on tests . 7
6 Ratings . 7
7 Classification . 8
8 Marking . 8
9 Dimensions. 8
10 Protection against electric shock . 8
11 Provision for earthing . 9
12 Construction . 9
13 Resistance to ageing, protection against ingress of solid objects and against
harmful ingress of water . 9
14 Insulation resistance and electric strength . 9
15 Mechanical strength . 9
16 Resistance to heat . 13
17 Creepage distances, clearances and distances through sealing compound . 14
18 Resistance of insulating material to abnormal heat and to fire . 14
19 Resistance to tracking . 14
20 Resistance to corrosion . 14
21 Electromagnetic compatibility (EMC) . 14

Figure 101 – Examples of suspension means . 7
Figure 102 – Examples of boxes and enclosures with provision for suspension means . 10
Figure 103 – Verification of suspension means intended to be used on a wall . 12
Figure 104 – Inclined ceiling test. 13

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

Part 21: Particular requirements for boxes and
enclosures with provision for suspension means

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
This redline version of the official IEC Standard allows the user to identify the changes
made to the previous edition IEC 60670-21:2004+AMD1:2016 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 60670-21:2024 RLV © IEC 2024
IEC 60670-21 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 2004 and
Amendment 1:2016. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) Complete revision of the tests and requirements of the suspension means.
The text of this International Standard is based on the following documents:
Draft Report on voting
23B/1534/FDIS 23B/1552/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all parts in the IEC 60670 series, published under the general title Boxes and enclosures
for electrical accessories for household and similar fixed installations, can be found on the IEC
website.
This document is to be used in conjunction with IEC 60670-1:2024. It lists the changes
necessary to convert that standard into a specific standard for housing protective devices and
other power dissipating electrical equipment.
Where this document states "addition", "modification" or "replacement", the relevant
requirement, test specifications or explanatory matter in IEC 60670-1:2024 shall be adapted
accordingly.
Clauses and subclauses, notes, figures or tables which are additional to those in
IEC 60670-1:2024 are numbered starting from 101.
Additional annexes to IEC 60670-1:2024 are numbered AA, BB, etc.
In this publication the following print types are used:
• requirements proper: in roman type.
• test specifications: in italic type.
• notes: in smaller roman type.

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

– 6 – IEC 60670-21:2024 RLV © IEC 2024
BOXES AND ENCLOSURES FOR ELECTRICAL ACCESSORIES FOR
HOUSEHOLD AND SIMILAR FIXED ELECTRICAL INSTALLATIONS –

Part 21: Particular requirements for boxes and
enclosures with provision for suspension means

1 Scope
Clause 1 of IEC 60670-1:2024 is applicable with the following modification:
Addition after the fourth third paragraph:
This document applies to boxes and enclosures for ceiling and wall mounting with provision for
suspension means.
2 Normative references
Clause 2 of IEC 60670-1:2024 is applicable.
3 Terms and definitions
Clause 3 of IEC 60670-1:2024 is applicable with the following modification:
Addition:
3.101
box with provision for suspension means
box intended to be used for suspending and supporting mechanical loads and which accepts
the suspension means
3.102
suspension means
means comprising any necessary components (hooks, brackets, etc.) which may be delivered
with the box and enclosure or supplied separately (see Figure 101)
Note 1 to entry: Examples of suspension means are shown in Figure 101.

a) Box provided with provision for suspension means

b) Suspension means
c) Box and enclosure delivered with suspension means

Figure 101 – Examples of suspension means
4 General requirements
Clause 4 of IEC 60670-1:2024 is applicable.
5 General notes remarks on tests
Clause 5 of IEC 60670-1:2024 is applicable.
6 Ratings
Void.
– 8 – IEC 60670-21:2024 RLV © IEC 2024
7 Classification
Clause 7 of IEC 60670-1:2024 is applicable with the following modification:
Addition to Table 1:
b
aa
7.101.1 For suspension of supporting a
7.101 The provision for suspension means
luminaire.
7.101.2 For suspension of supporting a ceiling
fan.
b
aa
The suspension means may be provided with the box or not.

8 Marking
Clause 8 of IEC 60670-1:2024 is applicable with the following modification:
8.1 General
Addition after item j):
k) the mass in kg, if the test force declared by the manufacturer is greater than 250 N for boxes
and enclosures classified according to 7.101.1.
NOTE 1 In the following countries boxes for luminaire support are marked "For luminaire support". Where boxes
are intended to support a mass greater than 15,8 kg, the mass is to be marked: US.
NOTE 2 In Denmark shall the marking in kg reflect a safety factor of 5 times.
Addition after item k):
l) for boxes and enclosures classified according to 7.101.1, the maximum supported mass in
kilograms declared by the manufacturer.
NOTE 101 In the following countries boxes for luminaire support are marked "For luminaire support". Where boxes
are intended to support a mass greater than 15,8 kg, the mass is to be marked: US.
NOTE 102 In the following country the marking in kilograms shall reflect a safety factor of 5 times: DK.
9 Dimensions
Clause 9 of IEC 60670-1:2024 is applicable.
10 Protection against electric shock
Clause 10 of IEC 60670-1:2024 is applicable with the following modification:
Addition:
Conductive parts of suspension means inside the box or enclosure shall be:
– protected by a layer of insulating material which complies with the tests for insulating linings,
or
– located such that it will not come in contact with electrical conductors or live parts, or
– reliably connected to the earthing means complying with requirements of 11.1 when fitted
as for normal use.
11 Provision for earthing
Clause 11 of IEC 60670-1:2024 is applicable.
12 Construction
Clause 12 of IEC 60670-1:2024 is applicable with the following modification:
Addition:
12.101 Provision for suspension means
Unless otherwise declared by the manufacturer, screws for fixing accessories and/or covers are
not considered as provision for suspension means.
12.102 Minimum mass to be supported by suspension means
Boxes and enclosures with provision for suspension means shall be able to support a mass of
at least 5 kg.
NOTE For fixing means of a luminaire, a minimum supported mass of 5 kg is given in IEC 60364-5-55:2011, 559.5.2.
Compliance is checked by the tests of 15.101.
13 Resistance to ageing, protection against ingress of solid objects and against
harmful ingress of water
Clause 13 of IEC 60670-1:2024 is applicable.
14 Insulation resistance and electric strength
Clause 14 of IEC 60670-1:2024 is applicable.
15 Mechanical strength
Clause 15 of IEC 60670-1:2024 is applicable with the following modification:
Addition:
1.10115.101 Boxes and enclosures with provision for suspension means
15.101.1 Boxes and enclosures with provision for suspension means shall withstand the
thermal and mechanical stresses occurring in normal use.
Boxes and enclosures with provision for suspension means according to:
– 7.101.1 shall comply with the requirements of 15.101.12 and 15.101.23;
– 7.101.2 shall comply with the requirements of 15.101.34.
Examples of boxes and enclosures with provision for suspension means are shown in
Figure 102.
– 10 – IEC 60670-21:2024 RLV © IEC 2024

a) Boxes and enclosures which are intended for suspension of loads from a ceiling.

b) Boxes and enclosures which are intended for suspension of loads from a wall

c) Boxes and enclosures which are intended to support a ceiling fan

Key
1 ceiling
2 wall
3 box
4 suspension mean
5 ceiling fan
Figure 102 – Examples of boxes and enclosures with provision for suspension means
15.101.12 Boxes and enclosures which are intended for suspension of loads from a ceiling
shall withstand a test force of 250 N or a higher test force Y X corresponding to five times the
maximum supported mass in kilograms declared by the manufacturer.
The test force F in newtons is the result of the maximum supported mass in kilograms multiplied
by the gravity and multiplied by a safety factor of 5; this value is rounded up to the next decimal,
for example: 5 kg × 9,81 m/s × 5 ≈ 245, gives a test force of 250 N.
NOTE 1 101 In the following countries there is no requirement for all boxes and enclosures for suspension means
to withstand 250 N and no requirement for non-metallic boxes and enclosures to withstand 90° C: UK.
NOTE 2102 In the following country, the test force Y shall correspond to 5 times the marking in kilograms as required
in item k) of 8.1: DK
NOTE 3103 In Spain, there are no requirements for all boxes and enclosures for suspension means to withstand
90 °C.
Compliance is checked by the following test.
The specimen is fitted with a suspension means and installed as for normal use according to
the manufacturer's instructions, any screw being tightened to two-thirds of the torque given in
the relevant column of Table 4.
Greater values of torque may be used if so declared by the manufacturer, when the relevant
information is provided.
The suspension means is then loaded with a weight of (250 ± 5) N or with a weight (Y ± 2 %) N
declared by the manufacturer, whichever is the higher, for 24 h.
For boxes and enclosures according to 7.1.1 and 7.1.3 the test is performed in a heating cabinet
at (90 ± 2)°C.
For boxes and enclosures according to 7.1.2 and 7.1.4 the test is performed at ambient
temperature.
A test force of (250 ± 5) N, or of (X ± 2 %) N, is applied to the suspension means for 24 h at
ambient temperature.
For boxes and enclosures according to 7.1.1 and 7.1.3 the test is repeated in a heating cabinet
at (90 ± 2) °C for 1 h with a test force of (50 ± 1) N, or a higher test force corresponding to the
mass declared by the manufacturer without considering the safety factor.
NOTE 4104 In the following country the test of this Subclause 15.101.2 shall be carried out at (80 ± 2) °C instead
of (90 ± 2) °C: NL.
During the test, the box and the enclosure or the suspension means shall not become detached
and the specimen shall show no damage which leads to non-compliance with this document.
15.101.23 Boxes and enclosures which are intended to be used in or on for suspension of
loads from a wall shall withstand a test force of 100 N or a higher test force Y corresponding to
two times the maximum supported mass in kilograms declared by the manufacturer.
NOTE 1 This means may be screws otherwise intended for fixing a part of the box, for example the cover or cover
plate.
NOTE 2 In the following countries there is no requirement for all suspension means to withstand 100 N: UK.
Compliance is checked by inspection and by the following test.
The box or the enclosure including covers and cover plates (if any) shall be installed as for
normal use according to the manufacturer's instructions and shall be placed in a heating
cabinet, any screw being tightened to two-thirds of the torque given in the relevant column of
Table 4.
A force, equally distributed between each means if more than one, of (100 ± 5) N or of (Y ± 2 %)
N declared by the manufacturer, is then applied for 24 h at (40 ± 2)°C perpendicularly to the
wall.
A force, equally distributed between each means if more than one, of (100 ± 2) N or of
(Y ± 2 %) N is then applied for 24 h at (40 ± 2) °C downward at a distance not exceeding 5 mm
protruding from the plane formed by the mounting surface of the luminaire as shown in
Figure 103.
– 12 – IEC 60670-21:2024 RLV © IEC 2024

Key
1 test specimen
2 sheet of plywood
3 lever
4 main axis of the box
Figure 103 – Verification of suspension means intended to be used on a wall
During the test, the box or enclosure or the suspension means shall not become detached and
the specimen shall show no damage which leads to non-compliance with this document.
15.101.34 Boxes and enclosures which are intended to support a ceiling fan shall withstand
the thermal and mechanical stress occurring in normal use.
During the test the box or enclosure or its supporting means shall not be pulled loose from the
test structure when subjected to the following tests.
One specimen shall be tested in each of the horizontal and inclined positions.
A specimen shall be mounted in accordance with the manufacturer’s instructions to a supporting
test structure so as to be tested while both in a horizontal position and inclined 30° from the
horizontal with the mounting screws perpendicular to the ceiling and the fan blades parallel to
the floor (see Figure 102 Figure 104).

Dimensions in millimetres
Key
1 Box
2 Ceiling
Figure 104 – Inclined ceiling test
A test fan having four blades with a diameter of (1 320 ± 25) mm, weighing or ballasted to a
weight of (155 ± 5) N (corresponding to a mass of (15,8 ± 0,5) kg) or the rated load Y declared
by the manufacturer, whichever is higher, shall be used for the tests. A 0,392 N (corresponding
to a mass of 40 g) imbalance shall be placed at the centre of gravity of one blade, measured
independently from the test fan.
The test fan shall be provided with a downrod of rigid metal pipe of a length sufficient to position
the lower end of the fan blades (305 ± 25) mm below the surface of the ceiling after mounting.
The downrod shall be welded at the upper end to a 7,9 mm thick fan mounting bracket.
The test fan mounting bracket shall be secured to the box or enclosure in accordance with the
manufacturer's instructions. Screws or nuts shall be tightened with a torque given in the relevant
column in Table 4. A universal type joint mounting construction shall not be used for the test.
The fan motor shall be such that the speed can be controlled.
The speed of the test fan shall be adjusted to maintain a blade tip speed of 1 220 m/min
(294 r/min).
The blade pitch shall be reduced to a minimum. The fan shall operate continuously at the
+1
prescribed speed for (24 ) h.
At the end of the 24 h, one of the cover retaining screws or nuts shall be loosened two full turns
and the fan shall operate as specified for an additional 24 h for each mounting condition,
horizontal and inclined. This additional test is not required for constructions that employ cover
retaining or fan mounting screws with captive, locking type washers or locknuts.
Additionally, there shall be no stripping of threads, cracking, crazing, breaking, or visible
damage to the box or enclosure or its supporting means (other than bending).
16 Resistance to heat
Clause 16 of IEC 60670-1:2024 is applicable.

– 14 – IEC 60670-21:2024 RLV © IEC 2024
17 Creepage distances, clearances and distances through sealing compound
Void.
18 Resistance of insulating material to abnormal heat and to fire
Clause 18 of IEC 60670-1:2024 is applicable.
19 Resistance to tracking
Clause 19 of IEC 60670-1:2024 is applicable.
20 Resistance to corrosion
Clause 20 of IEC 60670-1:2024 is applicable.
21 Electromagnetic compatibility (EMC)
Clause 21 of IEC 60670-1:2024 is applicable.
a) Box provided with provision for suspension means
Example of provision for suspension means

IEC  433/04
b) Suspension means
IEC  434/04
c) Box and enclosure delivered with suspension means

IEC  435/04
Figure 101 – Examples of suspension means

– 16 – IEC 60670-21:2024 RLV © IEC 2024

330 mm
30°
IEC  436/04
Key
1  Box
2  Ceiling
Figure 102 – Inclined ceiling test

___________
305 mm
IEC 60670-21 ®
Edition 2.0 2024-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Boxes and enclosures for electrical accessories for household and similar fixed
electrical installations –
Part 21: Particular requirements for boxes and enclosures with provision for
suspension means
Boîtes et enveloppes pour appareillage électrique pour installations électriques
fixes pour usages domestiques et analogues –
Partie 21: Règles particulières concernant les boîtes et enveloppes avec
dispositifs de suspension
– 2 – IEC 60670-21:2024 © IEC 2024
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 General requirements . 6
5 General remarks on tests . 6
6 Ratings . 6
7 Classification . 7
8 Marking . 7
9 Dimensions. 7
10 Protection against electric shock . 7
11 Provision for earthing . 7
12 Construction . 8
13 Resistance to ageing, protection against ingress of solid objects and against
harmful ingress of water . 8
14 Insulation resistance and electric strength . 8
15 Mechanical strength . 8
16 Resistance to heat . 12
17 Creepage distances, clearances and distances through sealing compound . 13
18 Resistance of insulating material to abnormal heat and to fire . 13
19 Resistance to tracking . 13
20 Resistance to corrosion . 13
21 Electromagnetic compatibility (EMC) . 13

Figure 101 – Examples of suspension means . 6
Figure 102 – Examples of boxes and enclosures with provision for suspension means . 9
Figure 103 – Verification of suspension means intended to be used on a wall . 11
Figure 104 – Inclined ceiling test. 12

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

Part 21: Particular requirements for boxes and
enclosures with provision for suspension means

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 60670-21 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 2004 and
Amendment 1:2016. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) Complete revision of the tests and requirements of the suspension means.

– 4 – IEC 60670-21:2024 © IEC 2024
The text of this International Standard is based on the following documents:
Draft Report on voting
23B/1534/FDIS 23B/1552/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all parts in the IEC 60670 series, published under the general title Boxes and enclosures
for electrical accessories for household and similar fixed installations, can be found on the IEC
website.
This document is to be used in conjunction with IEC 60670-1:2024. It lists the changes
necessary to convert that standard into a specific standard for housing protective devices and
other power dissipating electrical equipment.
Where this document states "addition", "modification" or "replacement", the relevant
requirement, test specifications or explanatory matter in IEC 60670-1:2024 shall be adapted
accordingly.
Clauses and subclauses, notes, figures or tables which are additional to those in
IEC 60670-1:2024 are numbered starting from 101.
Additional annexes to IEC 60670-1:2024 are numbered AA, BB, etc.
In this publication the following print types are used:
• requirements proper: in roman type.
• test specifications: in italic type.
• notes: in smaller roman type.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn, or
• revised.
BOXES AND ENCLOSURES FOR ELECTRICAL ACCESSORIES FOR
HOUSEHOLD AND SIMILAR FIXED ELECTRICAL INSTALLATIONS –

Part 21: Particular requirements for boxes and
enclosures with provision for suspension means

1 Scope
Clause 1 of IEC 60670-1:2024 is applicable with the following modification:
Addition after the third paragraph:
This document applies to boxes and enclosures for ceiling and wall mounting with provision for
suspension means.
2 Normative references
Clause 2 of IEC 60670-1:2024 is applicable.
3 Terms and definitions
Clause 3 of IEC 60670-1:2024 is applicable with the following modification:
Addition:
3.101
box with provision for suspension means
box intended to be used for suspending and supporting mechanical loads and which accepts
the suspension means
3.102
suspension means
means comprising any necessary components (hooks, brackets, etc.) which may be delivered
with the box and enclosure or supplied separately
Note 1 to entry: Examples of suspension means are shown in Figure 101.

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a) Box provided with provision for suspension means

b) Suspension means
c) Box and enclosure delivered with suspension means

Figure 101 – Examples of suspension means
4 General requirements
Clause 4 of IEC 60670-1:2024 is applicable.
5 General remarks on tests
Clause 5 of IEC 60670-1:2024 is applicable.
6 Ratings
Void.
7 Classification
Clause 7 of IEC 60670-1:2024 is applicable with the following modification:
Addition to Table 1:
b
7.101.1 For supporting a luminaire.
7.101 The provision for suspension means
7.101.2 For supporting a ceiling fan.
b
The suspension means may be provided with the box or not.

8 Marking
Clause 8 of IEC 60670-1:2024 is applicable with the following modification:
8.1 General
Addition after item k):
l) for boxes and enclosures classified according to 7.101.1, the maximum supported mass in
kilograms declared by the manufacturer.
NOTE 101 In the following countries boxes for luminaire support are marked "For luminaire support". Where boxes
are intended to support a mass greater than 15,8 kg, the mass is to be marked: US.
NOTE 102 In the following country the marking in kilograms shall reflect a safety factor of 5 times: DK.
9 Dimensions
Clause 9 of IEC 60670-1:2024 is applicable.
10 Protection against electric shock
Clause 10 of IEC 60670-1:2024 is applicable with the following modification:
Addition:
Conductive parts of suspension means inside the box or enclosure shall be:
– protected by a layer of insulating material which complies with the tests for insulating linings,
or
– located such that it will not come in contact with electrical conductors or live parts, or
– reliably connected to the earthing means complying with requirements of 11.1 when fitted
as for normal use.
11 Provision for earthing
Clause 11 of IEC 60670-1:2024 is applicable.

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12 Construction
Clause 12 of IEC 60670-1:2024 is applicable with the following modification:
Addition:
12.101 Provision for suspension means
Unless otherwise declared by the manufacturer, screws for fixing accessories and/or covers are
not considered as provision for suspension means.
12.102 Minimum mass to be supported by suspension means
Boxes and enclosures with provision for suspension means shall be able to support a mass of
at least 5 kg.
NOTE For fixing means of a luminaire, a minimum supported mass of 5 kg is given in IEC 60364-5-55:2011, 559.5.2.
Compliance is checked by the tests of 15.101.
13 Resistance to ageing, protection against ingress of solid objects and against
harmful ingress of water
Clause 13 of IEC 60670-1:2024 is applicable.
14 Insulation resistance and electric strength
Clause 14 of IEC 60670-1:2024 is applicable.
15 Mechanical strength
Clause 15 of IEC 60670-1:2024 is applicable with the following modification:
Addition:
15.101 Boxes and enclosures with provision for suspension means
15.101.1 Boxes and enclosures with provision for suspension means shall withstand the
thermal and mechanical stresses occurring in normal use.
Boxes and enclosures with provision for suspension means according to:
– 7.101.1 shall comply with the requirements of 15.101.2 and 15.101.3;
– 7.101.2 shall comply with the requirements of 15.101.4.
Examples of boxes and enclosures with provision for suspension means are shown in
Figure 102.
a) Boxes and enclosures which are intended for suspension of loads from a ceiling.

b) Boxes and enclosures which are intended for suspension of loads from a wall

c) Boxes and enclosures which are intended to support a ceiling fan

Key
1 ceiling
2 wall
3 box
4 suspension mean
5 ceiling fan
Figure 102 – Examples of boxes and enclosures with provision for suspension means
15.101.2 Boxes and enclosures which are intended for suspension of loads from a ceiling shall
withstand a test force of 250 N or a higher test force X corresponding to five times the maximum
supported mass in kilograms declared by the manufacturer.
The test force F in newtons is the result of the maximum supported mass in kilograms multiplied
by the gravity and multiplied by a safety factor of 5; this value is rounded up to the next decimal,
for example: 5 kg × 9,81 m/s × 5 ≈ 245, gives a test force of 250 N.
NOTE 101 In the following countries there is no requirement for all boxes and enclosures for suspension means to
withstand 250 N and no requirement for non-metallic boxes and enclosures to withstand 90° C: UK.
NOTE 102 In the following country, the test force Y shall correspond to 5 times the marking in kilograms as required
in item k) of 8.1: DK
NOTE 103 In Spain, there are no requirements for all boxes and enclosures for suspension means
...