EN IEC 61439-4:2026

• Abstract:

  NOTE Throughout this standard, the abbreviation ACS (ASSEMBLY for construction site, see 3.1.101) is used for a low-voltage switchgear and controlgear assembly intended for use on construction and similar sites. This part of 61439 defines the specific requirements of ACS as follows: - ASSEMBLIES for which the rated voltage does not exceed 1 000 V in case of AC or 1 500 V in case of DC; - ASSEMBLIES where the nominal primary voltage and the nominal secondary voltage of transformers incorporated in ACS are within the limits specified above; - ASSEMBLIES intended for use on construction sites, both indoors and outdoors, i.e. temporary places of work to which the public do not generally have access and where building construction, installation, repairs, alteration or demolition of property (buildings) or civil engineering (public works) or excavation or any other similar operations are carried out; - transportable (semi-fixed) or mobile ASSEMBLIES with enclosure. The manufacture and/or assembly may be carried out other than by the original manufacturer. This standard does not apply to individual devices and self-contained components, such as motor starters, fuse switches, electronic equipment, etc. which will comply with the relevant product standards. This standard does not apply to ASSEMBLIES for use in the administrative centres of construction sites (offices, cloakrooms, ASSEMBLY rooms, canteens, restaurants, dormitories, toilets, etc.). Requirements for electrical protection provided by equipment manufactured according to this International Standard are given in IEC 60364-7-704.

• Status: Not Published
• Publication Date: 29-Oct-2026
• ICS: 29.130.20 - Low voltage switchgear and controlgear
• Technical Committee: CLC/SR 121B - Low-voltage switchgear and controlgear assemblies
• Drafting Committee: IEC/SC 121B - Low-voltage switchgear and controlgear assemblies
• Current Stage: 6055 - Ratification Completed (DOR) - Publishing
• Start Date: 16-Oct-2024
• Completion Date: 16-Oct-2024
• Directive: 2014/30/EU - Directive 2014/30/EU of the European Parliament and of the Council of 26 February 2014 on the harmonisation of the laws of the Member States relating to electromagnetic compatibility (recast)
• Directive:

  ---

  2014/35/EU - Directive 2014/35/EU of the European Parliament and of the Council of 26 February 2014 on the harmonisation of the laws of the Member States relating to the making available on the market of electrical equipment designed for use within certain voltage limits
• Mandate: M/511 - Mandate to CEN, CENELEC and ETSI relating to harmonised standards in the field of the Low Voltage Directive
• Ref Project: kSIST FprEN IEC 61439-4:2023 - Low-voltage switchgear and controlgear assemblies - Part 4: Particular requirements for assemblies for construction sites (ACS)

• Refers: EN IEC 61558-2-23:2025 - Safety of transformers, reactors, power supply units and combinations thereof - Part 2-23: Particular requirements and tests for transformers and power supply units for construction sites
• Effective Date: 13-Oct-2026
• Refers: EN 60068-2-27:2009 - Environmental testing - Part 2-27: Tests - Test Ea and guidance: Shock
• Effective Date: 13-Oct-2026
• Refers: EN 60068-2-42:2003 - Environmental testing - Part 2-42: Tests - Test Kc: Sulphur dioxide test for contacts and connections
• Effective Date: 13-Oct-2026
• Refers: EN IEC 61439-1:2021 - Low-voltage switchgear and controlgear assemblies - Part 1: General rules
• Effective Date: 13-Oct-2026
• Refers: HD 60364-7-704:2018 - Low voltage electrical installations - Part 7-704: Requirements for special installations or locations - Construction and demolition site installations
• Effective Date: 13-Oct-2026
• Revises: EN 61439-4:2013 - Low-voltage switchgear and controlgear assemblies - Part 4: Particular requirements for assemblies for construction sites (ACS)
• Effective Date: 26-Jul-2021

EN IEC 61439-4:2026 is the CLC/CENELEC standard for low-voltage switchgear and controlgear assemblies for construction sites (ACS). It specifies the particular requirements for ACS used on indoor and outdoor construction and similar sites, including transportable (semi-fixed) and mobile enclosed assemblies. Manufacturers, assemblers, designers, and users use it to define ratings, construction, documentation, and verification for these assemblies.

What does EN IEC 61439-4:2026 specify?

EN IEC 61439-4:2026 covers ACS with rated voltage up to 1 000 V AC or 1 500 V DC, including assemblies with incorporated transformers whose primary and secondary voltages stay within those limits. It applies to construction-site use, not to administrative centres on a site, and it excludes individual devices and self-contained components that are covered by their own product standards.

The standard is organized into Clauses 1 to 11, with Clause 101 adding ACS-specific features. It is read together with IEC 61439-1, so the general rules in Part 1 apply unless this part modifies or replaces them.

Annex	What it covers
C	User information template and items to agree between the manufacturer and the user
D	Design verification list and the verification method for each characteristic
L	Guidance on temperature-rise verification
M	Verification of short-circuit withstand strength of busbar structures by comparison with a tested reference design by calculation; this part states that the Part 1 annex is not applicable here
N	Notes on certain country practices
AA	Void

What are the key requirements of EN IEC 61439-4:2026?

EN IEC 61439-4:2026 focuses on the ratings, enclosure, protection, and verification needed for site use. In practice, it tells the manufacturer what to declare, how to build the ACS, and what to prove by test or assessment before the assembly is supplied.

Ratings, declared characteristics, and marking

Clause 5.3.1 ties the ACS rated current to the incoming circuit, so the incoming side must carry the declared current without exceeding the temperature-rise limits of Part 1. Clause 5.4 requires the manufacturer to declare the rated diversity factor (RDF) or use the table values, which matters when the outgoing circuits are not expected to run at full load all at once.

Clause 5.6 requires the manufacturer to declare the function(s), external design, mobility, degree of protection, mounting method, protection against electric shock, corrosion resistance, special service conditions, and EMC classification. Clause 6 then requires durable marking on the ACS and supporting technical documentation. For a buyer or site designer, this is the basic information needed to match the assembly to the job, the network, and the site conditions.

Clause 6.2.2 also expects the documentation to state which other assemblies may be connected, and whether the compatibility depends on the earthing system or on co-ordination of protective devices. That helps avoid mismatched equipment in a chain of site distribution assemblies.

Service conditions and construction

Clause 7 limits the normal pollution degree to 3 or 4. A microenvironment may be reduced to pollution degree 2 only if the enclosure is at least IP5X and condensation is avoided. Clause 7 also adds heavily polluted atmosphere as a special service condition, which matters for outdoor and industrial construction sites.

Clause 8 places all apparatus inside the enclosure, except for the items allowed by 8.101, and requires protection against corrosion, ultraviolet radiation for insulating external parts, lifting provision, and mechanical strength. It also requires the ACS to withstand the site-related shock and impact conditions defined in the clause. In practice, this is what drives the choice of enclosure material, coating, handles, feet, and wall-fixing arrangements.

Clause 8.2.2 sets the minimum degree of protection at IP44 for the ACS with doors closed and removable parts fitted. It also sets minimum protection for operating faces, doors, and socket-outlets, and requires the declared IP rating to match verified test results. Clause 8.5.3 prevents plugs with different current or voltage ratings from being interchangeable, and requires three-phase connections to keep the same phase order. Clause 8.5.101 limits freely accessible parts to socket-outlets, operating handles, and control buttons, while the main switch actuator must be easily accessible.

Clause 8.8 requires external cable connections to be re-wireable or socket-outlets, and the socket-outlets must have at least 16 A rating. Clause 8.101 requires supports or a wall-fixing system, and Clause 8.102 places the cable outlet high enough for the bending radius of the largest connected cable. These points are practical site-use rules: the ACS must stand safely, be easy to connect, and avoid cable damage.

ACS functional arrangement

Clause 101 defines the ACS as one incoming unit with one or more outgoing units, and it may also include metering units and transformer units. The incoming unit needs a means of isolation and overcurrent protection, plus a way to secure the isolating device in the open position. If upstream protection is used instead, the manufacturer has to give the user the information needed to select it correctly.

Metering units intended for billing purposes need agreement with the energy supplier. Transformer units may be LV/ELV or LV/LV, and the transformers are required to follow IEC 61558-2-23. Outgoing units must provide isolation, load switching, overcurrent protection, and fault protection, and socket-outlet circuits need protection against electric shock and overcurrent. Table 101 gives assumed loading factors for groups of outgoing circuits, which helps the manufacturer declare realistic loading for site distribution.

Design verification and routine checks

Clause 10 and Annex D organize the design verification of the ACS. Table D.1 shows which characteristics are verified by testing, comparison with a reference design, or assessment. The standard includes corrosion testing for heavily polluted atmosphere, mechanical impact and shock testing, verification of enclosure protection, dielectric tests, temperature-rise checks, short-circuit withstand verification, EMC, and mechanical operation.

Where an empty IEC 62208 enclosure is used without performance-degrading changes, the enclosure tests do not need to be repeated except for mechanical strength, unless the ACS is declared for heavily polluted atmosphere. Clause 11 covers routine verification, so each manufactured ACS still needs the checks required before delivery.

What terms does EN IEC 61439-4:2026 define?

EN IEC 61439-4:2026 defines ACS as a low-voltage switchgear and controlgear assembly for construction sites, with the internal electrical and mechanical connections needed for site use indoors and outdoors.

A metering unit is a functional unit equipped with apparatus for metering electrical energy. It is the part used when site energy consumption has to be measured.

A transformer unit is a functional unit consisting mainly of one or more transformers. The standard uses this for ACS that need LV/ELV or LV/LV conversion.

An enclosed ACS is enclosed on all sides, except possibly the mounting surface, so that it provides a defined degree of protection. This is the normal form for site use.

A box-type ACS is an enclosed ACS intended either for mounting on a vertical surface or for standing on a horizontal surface with feet, legs, or a separate mounting arrangement. This affects installation and handling on site.

A transportable ACS is a semi-fixed ACS that is not permanently fixed and may be moved on the same site after disconnection from the supply. A mobile ACS can be moved as work advances without being disconnected from the supply.

The rated diversity factor (RDF) is the declared assumed loading of outgoing circuits or groups of outgoing circuits. It matters because it is part of the current-sizing and load-assumption basis for the assembly.

Who uses EN IEC 61439-4:2026?

EN IEC 61439-4:2026 is used by ACS manufacturers, panel builders, and assemblers who design and build site distribution assemblies. It is also used by electrical designers, temporary power contractors, construction-site operators, energy suppliers involved with metering units, test laboratories, and quality or procurement teams that need to check ratings, protection, IP level, and documentation.

What changed in EN IEC 61439-4:2026 from the previous edition?

The text states that this edition cancels and replaces IEC 60439-4:2004 and is a technical revision. The significant changes listed are:

• the title was changed to “Part 4: Particular requirements for assemblies for construction sites (ACS)”
• the structure and technical content were aligned with IEC 61439-1 where applicable
• the standard was adapted to allow comparison with tested ACS

Which standards are used with EN IEC 61439-4:2026?

Standard	What it contributes
IEC 61439-1	General rules for low-voltage switchgear and controlgear assemblies
IEC 60364-7-704	Installation requirements for construction and demolition site installations
IEC 61140	Common aspects of protection against electric shock
IEC 60068-2-27	Shock test used for mechanical impact and shock verification
IEC 60068-2-42	Sulphur dioxide corrosion test for heavily polluted atmosphere
IEC 61558-2-23	Requirements and tests for transformers and power supply units for construction sites

What does the EN IEC 61439-4:2026 document contain?

EN IEC 61439-4:2026 contains the declaration information, construction rules, service-condition limits, and verification methods needed for ACS. It includes a user information template in Annex C, a design-verification list in Annex D, a table of assumed loading values, and a test figure for impact verification.

The document also gives the ACS-specific functional structure in Clause 101, covering incoming units, outgoing units, metering units, and transformer units. For design and test work, it provides the practical checks for marking, IP rating, corrosion, mechanical strength, short-circuit withstand, EMC, and routine verification.

SLOVENSKI STANDARD
oSIST prEN IEC 61439-4:2022
01-julij-2022
Sestavi nizkonapetostnih stikalnih in krmilnih naprav - 4. del: Posebne zahteve za
sestave na gradbiščih (ACS)
Low-voltage switchgear and controlgear assemblies - Part 4: Particular requirements for
assemblies for construction sites (ACS)
Niederspannungs-Schaltgerätekombinationen - Teil 4: Besondere Anforderungen für
Baustromverteiler (BV)
Ensembles d'appareillage à basse tension - Partie 4: Exigences particulières pour
ensembles de chantiers (EC)
Ta slovenski standard je istoveten z: prEN IEC 61439-4:2022
ICS:
29.130.20 Nizkonapetostne stikalne in Low voltage switchgear and
krmilne naprave controlgear
91.200 Gradbena tehnologija Construction technology
oSIST prEN IEC 61439-4:2022 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN IEC 61439-4:2022
oSIST prEN IEC 61439-4:2022
121B/151/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 61439-4 ED2
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2022-05-13 2022-08-05
SUPERSEDES DOCUMENTS:
121B/142/CD, 121B/149/CC
IEC SC 121B : LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR ASSEMBLIES
SECRETARIAT: SECRETARY:
Germany Mr Jörg Hußmann
OF INTEREST TO THE FOLLOWING COMMITTEES: PROPOSED HORIZONTAL STANDARD:

TC 64,SC 121A
Other TC/SCs are requested to indicate their interest, if
any, in this CDV to the secretary.
FUNCTIONS CONCERNED:
EMC ENVIRONMENT QUALITY ASSURANCE SAFETY

SUBMITTED FOR CENELEC PARALLEL VOTING NOT SUBMITTED FOR CENELEC PARALLEL VOTING
Attention IEC-CENELEC parallel voting
The attention of IEC National Committees, members of
CENELEC, is drawn to the fact that this Committee Draft
for Vote (CDV) is submitted for parallel voting.
The CENELEC members are invited to vote through the
CENELEC online voting system.
This document is still under study and subject to change. It should not be used for reference purposes.
Recipients of this document are invited to submit, with their comments, notification of any relevant patent rights of
which they are aware and to provide supporting documentation.

TITLE:
Low-voltage switchgear and controlgear assemblies - Part 4: Particular requirements for
assemblies for construction sites (ACS)

PROPOSED STABILITY DATE: 2026
NOTE FROM TC/SC OFFICERS:
download this electronic file, to make a copy and to print out the content for the sole purpose of preparing National
Committee positions. You may not copy or "mirror" the file or printed version of the document, or any part of it, for
any other purpose without permission in writing from IEC.

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1 CONTENTS
3 1 Scope . 5
4 2 Normative references . 5
5 3 Terms and definitions . 6
6 3.1 General terms . 6
7 3.2 Constructional units of ASSEMBLIES . 6
8 3.3 External design of ASSEMBLIES . 6
9 3.5 Conditions of installation of ASSEMBLIES . 7
10 4 Symbols and abbreviations . 8
11 5 Interface characteristics . 8
12 6 Information . 8
13 7 Service conditions . 10
14 8 Constructional requirements . 10
15 9 Performance requirements . 13
16 10 Design verification . 13
17 11 Routine verification . 16
18 101 Particular features of ACS . 16
19 Annex C (informative) User information template . 20
20 Annex N (informative) List of notes concerning certain countries . 27
21 Annex AA (Void) . 28
23 Figure 101 – Impact test using striking element . 15
25 Table 101 – Values of assumed loading . 18
26 Table C.1 – Items subject to agreement between the ASSEMBLY manufacturer and the
27 user . 20
28 Table D.1 – List of design verifications to be performed . 24
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32 INTERNATIONAL ELECTROTECHNICAL COMMISSION
33 ____________
35 LOW-VOLTAGE SWITCHGEAR AND
36 CONTROLGEAR ASSEMBLIES –
38 Part 4: Particular requirements for assemblies
39 for construction sites (ACS)
41 FOREWORD
42 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
43 all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
44 international co-operation on all questions concerning standardization in the electrical and electronic fields. To
45 this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
46 Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
47 Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
48 in the subject dealt with may participate in this preparatory work. International, governmental and non-
49 governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
50 with the International Organization for Standardization (ISO) in accordance with conditions determined by
51 agreement between the two organizations.
52 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
53 consensus of opinion on the relevant subjects since each technical committee has representation from all
54 interested IEC National Committees.
55 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
56 Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
57 Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
58 misinterpretation by any end user.
59 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
60 transparently to the maximum extent possible in their national and regional publications. Any divergence
61 between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
62 the latter.
63 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
64 assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
65 services carried out by independent certification bodies.
66 6) All users should ensure that they have the latest edition of this publication.
67 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
68 members of its technical committees and IEC National Committees for any personal injury, property damage or
69 other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
70 expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
71 Publications.
72 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
73 indispensable for the correct application of this publication.
74 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
75 patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
76 International Standard IEC 61439-4 has been prepared by subcommittee 17D: Low-voltage
77 switchgear and controlgear assemblies, of IEC technical committee 17: Switchgear and
78 controlgear.
79 This first edition of IEC 61439-4 cancels and replaces the second edition of IEC 60439-4
80 (2004) and constitutes a technical revision.
81 This edition includes the following significant technical changes with respect to the last edition
82 of IEC 60439-4:
83 • modification of the title as “Part 4: Particular requirements for assemblies for construction
84 sites (ACS)”
85 • alignment on IEC 61439-1 regarding the structure and technical content, as applicable;
86 • to allow comparison with tested ACS.

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87 The text of this standard is based on the following documents:
FDIS Report on voting
17D/460/FDIS 17D/469/RVD
89 Full information on the voting for the approval of this standard can be found in the report on
90 voting indicated in the above table.
91 This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
92 This standard is to be read in conjunction with IEC 61439-1. The provisions of the general
93 rules dealt with in IEC 61439-1 (hereinafter referred to as Part 1) are only applicable to this
94 standard insofar as they are specifically cited. When this standard states “addition”,
95 “modification” or “replacement”, the relevant text in Part 1 is to be adapted accordingly.
96 Subclauses that are numbered with a 101 (102, 103, etc.) suffix are additional to the same
97 subclause in Part 1.
98 Tables and figures in this Part 4 that are new are numbered starting with 101.
99 New annexes in this Part 4 are lettered AA, BB, etc.
100 In this standard, terms written in small capitals are defined in Clause 3.
101 The reader’s attention is drawn to the fact that Annex AA lists all of the “in-some-country”
102 clauses on differing practices of a less permanent nature relating to the subject of this
103 standard.
104 A list of all parts of the IEC 61439 series, under the general title Low-voltage switchgear and
105 controlgear assemblies, can be found on the IEC website.
106 The committee has decided that the contents of this publication will remain unchanged until
107 the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
108 related to the specific publication. At this date, the publication will be
109 • reconfirmed,
110 • withdrawn,
111 • replaced by a revised edition, or
112 • amended.
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115 LOW-VOLTAGE SWITCHGEAR AND
116 CONTROLGEAR ASSEMBLIES –
118 Part 4: Particular requirements for assemblies
119 for construction sites (ACS)
122 1 Scope
123 NOTE Throughout this standard, the abbreviation ACS (ASSEMBLY for construction site, see 3.1.101) is used for
124 a low-voltage switchgear and controlgear assembly intended for use on construction and similar sites.
125 This part of 61439 defines the specific requirements of ACS as follows:
126 – ASSEMBLIES for which the rated voltage does not exceed 1 000 V in case of AC or 1 500 V
127 in case of DC;
128 – ASSEMBLIES where the nominal primary voltage and the nominal secondary voltage of
129 transformers incorporated in ACS are within the limits specified above;
130 – ASSEMBLIES intended for use on construction sites, both indoors and outdoors, i.e.
131 temporary places of work to which the public do not generally have access and where
132 building construction, installation, repairs, alteration or demolition of property (buildings)
133 or civil engineering (public works) or excavation or any other similar operations are carried
134 out;
135 – transportable (semi-fixed) or mobile ASSEMBLIES with enclosure.
136 The manufacture and/or assembly may be carried out other than by the original manufacturer.
137 This standard does not apply to individual devices and self-contained components, such as
138 motor starters, fuse switches, electronic equipment, etc. which will comply with the relevant
139 product standards.
140 This standard does not apply to ASSEMBLIES for use in the administrative centres of
141 construction sites (offices, cloakrooms, ASSEMBLY rooms, canteens, restaurants, dormitories,
142 toilets, etc.).
143 Requirements for electrical protection provided by equipment manufactured according to this
144 International Standard are given in IEC 60364-7-704.
145 2 Normative references
146 This clause of Part 1 is applicable except as follows:
147 Addition:
148 IEC 60068-2-27:2008, Environmental testing − Part 2-27: Tests – Test Ea and guidance:
149 Shock
150 IEC 60068-2-42:2003, Environmental testing − Part 2-42: Tests – Test Kc: Sulphur dioxide
151 test for contacts and connections
152 IEC 60364-7-704, 2017, Low-voltage electrical installations − Part 7-704: Requirements for
153 special installations or locations – Construction and demolition site installations
154 IEC 61140, 2016, Protection against electric shock – Common aspects for installation and
155 equipment
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156 IEC 61439-1, 2020, Low-voltage switchgear and controlgear assemblies – Part 1: General
157 rules
158 IEC 61558-2-23, 2010 Safety of transformers, reactors, power supply units and combinations
159 thereof – Part 2-23: Particular requirements and tests for transformers and power supply units
160 for construction sites
161 3 Terms and definitions
162 This clause of Part 1 is applicable except as follows:
163 Additional terms:
164 3.1 General terms
165 3.1.101
166 low-voltage switchgear and controlgear assembly for construction sites
167 ACS
168 combination of one or several transforming or low voltage switching devices with associated
169 control, measuring, signalling, protective and regulating equipment complete with all their
170 internal electrical and mechanical connections and structural parts, designed and built for use
171 on all construction sites, indoors and outdoors
172 3.2 Constructional units of ASSEMBLIES
173 3.2.101
174 metering unit
175 functional unit equipped with apparatus for metering electrical energy
176 3.2.102
177 transformer unit
178 functional unit consisting mainly of one or several transformers
179 Modifications:
180 3.3 External design of ASSEMBLIES
181 3.3.1
182 open-type ASSEMBLY
183 This term of Part 1 does not apply.
184 3.3.2
185 dead-front ASSEMBLY
186 This term of Part 1 does not apply.
187 Replacements:
188 3.3.3
189 enclosed ACS
190 ACS which is enclosed on all sides with the possible exception of its mounting surface in such
191 a manner as to provide a defined degree of protection
192 3.3.7
193 box-type ACS
194 enclosed ACS intended:
195 – either to be mounted on a vertical surface;

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196 – or to stand on a horizontal surface supported by feet or legs (articulated or not) or by a
197 mounting not forming part of the ACS (see 3.4.2 of Part 1)
198 Modifications:
199 3.5 Conditions of installation of ASSEMBLIES
200 3.5.1
201 ASSEMBLY for indoor installation
202 This term of Part 1 does not apply (see 3.1.101).
203 3.5.2
204 ASSEMBLY for outdoor installation
205 This term of Part 1 does not apply (see 3.1.101).
206 3.5.3
207 ASSEMBLY
stationary
208 This term of Part 1 does not apply.
209 3.5.4
210 movable ASSEMBLY
211 This term of Part 1 does not apply.
212 Additional terms:
213 3.5.101
214 transportable ACS
215 semi-fixed ACS
216 ACS intended for use in a place where it is not permanently fixed; its location may vary during
217 work on the same site. When the equipment shall be moved to another place, it is first
218 disconnected from the supply
219 3.5.102
220 mobile ACS
221 ACS capable of being moved as work advances on the site, without being disconnected from
222 the supply
224 Additional terms:
225 3.101 Function of the ACS
226 3.101.1
227 incoming supply function
228 suitability for connection of the ACS either to electricity public supply network or to the
229 transformer substation or to on site generator
230 3.101.2
231 metering function
232 suitability for the metering of electrical energy consumed on the site
233 3.101.3
234 distribution function
235 suitability to provide the distribution and protection of electrical supply on the construction site
236 by means of terminal connection or socket-outlets

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237 3.101.4
238 transformer function
239 suitability to provide means for transformer voltages or to provide measures of electrical
240 protection
241 Note 1 to entry: Details for their requirements are given in 101.1.
242 4 Symbols and abbreviations
243 This clause of Part 1 is applicable.
244 5 Interface characteristics
245 This clause of Part 1 is applicable except as follows.
246 ASSEMBLY (I )
5.3.1 Rated current of the
nA
247 Replacement of title and text:
248 5.3.1 Rated current of an ACS (I )
nA
249 The rated current of an ACS is that of its incoming circuit.
250 This current shall be carried without the temperature rise of the individual parts exceeding the
251 limits specified in 9.2 of Part 1.
252 5.4 Rated diversity factor (RDF)
253 Addition:
254 The assumed loading of the outgoing circuits of the ACS or group of outgoing circuits shall be
255 declared by the ASSEMBLY manufacturer and may be based on the values in Table 101.
256 When the manufacturer does not declare any RDF the values of Table 101 apply.
257 5.6 Other characteristics
258 Replacement:
259 The following characteristics shall be declared:
260 a) the function(s) assigned by the manufacturer (see 3.101);
261 b) the external design (see 3.3);
262 c) the mobility (see 3.5.101 and 3.5.102);
263 d) the degree of protection (see 8.2);
264 e) the method of mounting, for example fixed or removable parts (see 8.5.1 and 8.5.2);
265 f) protection against electric shock (see 8.4);
266 g) the resistance to corrosion (see 10.2.2.101);
267 h) special service conditions, if applicable (see 7.2);
268 i) electromagnetic compatibility (EMC) classification (see Annex J of Part 1).
269 6 Information
270 This clause of Part 1 is applicable except as follows.

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271 6.1 ASSEMBLY designation marking
272 Replacement of title and text:
273 6.1 ACS designation marking
274 ASSEMBLY manufacturer shall provide each ACS with one or more labels, marked in a
The
275 durable manner and located in a place such that they are visible and legible when the ACS is
276 installed and in operation.
277 Compliance is checked according to the test of 10.2.7 and by inspection.
278 The following information regarding the ACS shall be provided on the label(s):
279 a) ASSEMBLY manufacturer's name or trade mark (see 3.10.2);
280 b) type designation or identification number or any other means of identification, making it
281 possible to obtain relevant information from the ASSEMBLY manufacturer;
282 c) means of identifying date of manufacture;
283 d) IEC 61439-4;
284 e) type of current (and the frequency in the case of AC);
285 f) rated voltage (Un) (of the ACS) (see 5.2.1);
286 g) rated current of the ACS (InA) (see 5.3.1);
287 h) degree of protection (see 8.2);
288 i) the weight where this exceeds 30 kg.
289 If the indication of the name or trademark of the manufacturer appears on the ACS it need not
290 be given on the nameplate.
291 6.2.1 Information relating to the ASSEMBLY
292 Replacement of title and text:
293 6.2.1 Information relating to the ACS
294 The following additional information, where applicable, shall be provided in the ASSEMBLY
295 manufacturer’s technical documentation supplied with the ACS:
296 a) rated operational voltage (Ue) (of a circuit) (see 5.2.2);
297 b) rated impulse withstand voltage (U ) (see 5.2.4);
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298 c) rated insulation voltage (Ui) (see 5.2.3);
299 d) rated current of each circuit (I ) (see 5.3.2);
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300 e) rated peak withstand current (Ipk) (see 5.3.4);
301 f) rated short-time withstand current (I ) together with its duration (see 5.3.4);
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302 g) rated conditional short-circuit current (Icc) (see 5.3.5);
303 h) rated frequency (f ) (see 5.5);
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304 i) rated diversity factor(s) (RDF) (see 5.4);
305 j) functions (see 3.101);
306 k) all necessary information relating to the other declared classifications and characteristics
307 (see 5.6);
308 l) the short-circuit withstand strength and characteristics of short-circuit protective device(s)
309 (see 9.3.2);
310 m) overall dimensions (including projections e.g handles, covers, doors).

oSIST prEN IEC 61439-4:2022
IEC CDV 61439-4 © IEC 2022 10 121B/151/CDV

311 6.2.2 Instructions for handling, installation, operation and maintenance
312 Addition:
313 The manufacturer of the ACS should specify in its technical documentation supplied with the
314 ACS the other types of assemblies which may be connected to it. This information should
315 indicate whether the compatibility is based upon the type of system earthing employed and/or
316 on the need for co-ordination of the electrical protection within the complete installation.
317 The manufacturer should furnish the appropriate documentation for the purpose to maintain
318 the protective measures and the co-ordination of the protective devices within the complete
319 installation.
320 7 Service conditions
321 This clause of Part 1 is applicable except as follows.
322 Modifications:
323 7.1.2 Pollution degree
324 Replacement of the last paragraph with:
325 Only pollution degrees 3 and 4 are applicable.
326 The microenvironment may be reduced to pollution degree 2 if the degree of protection of the
327 enclosure is at least IP5X and care is taken to avoid condensation.
328 7.2 Special service conditions
329 Addition of the following new item:
330 m) heavily polluted atmosphere.
331 8 Constructional requirements
332 This clause of Part 1 is applicable except as follows.
333 8.1.1 General
334 Addition:
335 All the apparatus shall be placed inside the enclosure fitted with such removable panels,
336 cover plates or doors as may be required for connection or maintenance with the possible
337 exception of the items mentioned in 8.101 provided that they withstand the service conditions
338 of Clause 7 and the requirements of 8.1.2 and 8.1.6.
339 8.1.2 Protection against corrosion
340 Replacement:
341 Protection against corrosion shall be ensured by the use of suitable materials or by protective
342 coatings to the exposed surface taking account of the normal service conditions (see 7.1)
343 and/or special service condition (see 7.2). Compliance to this requirement is checked by the
344 test of 10.2.2.
oSIST prEN IEC 61439-4:2022
IEC CDV 61439-4 © IEC 2022 11 121B/151/CDV

345 8.1.4 Resistance to ultra-violet radiation
346 Replacement:
347 For enclosures and external parts made of insulating materials, resistance to ultra-violet
348 radiation shall be verified according to 10.2.4.
349 For external parts made of insulating material of components covered by other IEC standard
350 (for examples socket-outlets, handles of switch, push buttons etc) this test is not required.
351 8.1.5 Mechanical strength
352 Addition:
353 The ACS shall be constructed to withstand mechanical shocks having an acceleration of
354 , a pulse shape of a half-sine wave of 11 ms duration (commensurate with equipment
500 m/s
355 being carried loose in normal road or rail vehicles for long periods).
356 Compliance is verified according to 10.2.6.
357 8.1.6 Lifting provision
358 Replacement:
359 Lifting rings and/or handles (or any other equivalent system) shall be provided on the ACS
360 and be firmly attached to the enclosure or supporting framework.
361 Compliance is checked according to the test of 10.2.5.
362 8.2.1 Protection against mechanical impact
363 Additional paragraph:
364 The ACS shall also withstand impacts of 6 joules energy representing collisions with site
365 construction mechanical handling equipment (see IEC 60068-2-27).
366 For protection against mechanical impact refer to 10.2.6.
367 8.2.2 Protection against contact with live parts, ingress of solid foreign bodies and
368 water
369 Replacement:
370 The degree of protection provided by an ACS against contact with live parts, ingress of solid
371 foreign bodies and water is indicated by the IP code according to IEC 60529 and verified
372 according to 10.3.
373 The degree of protection of the ACS shall be at least IP 44, with all doors closed and all
374 removable panels and cover plates fitted.
375 Ventilation and drainage holes shall not reduce this degree of protection.
376 The degree of protection for an operating face inside a door shall be not less than IP 21
377 provided that the door can be closed under all conditions of use. Where the door cannot be
378 closed the degree of protection for the operating face shall be at least IP 44.

oSIST prEN IEC 61439-4:2022
IEC CDV 61439-4 © IEC 2022 12 121B/151/CDV

379 Unless otherwise specified, the degree of protection indicated by the original manufacturer
380 applies to the complete ACS, when it is installed in accordance with the original
381 manufacturer's instructions.
382 Socket-outlets not protected by the enclosure of the ACS shall have a degree of protection at
383 least equivalent to IP 44, both when the plug is removed or fully inserted.
384 Where the ACS does not have the same IP rating throughout, the original manufacturer shall
385 declare in its technical documentation supplied with the ACS the IP rating for the separate
386 parts. Example: IP 44, operating face IP 21.
387 No IP codes may be given unless the appropriate verifications have been made according to
388 10.3.
389 8.4.3.1 Installation conditions
390 Replacement of the first two paragraphs:
391 The ACS shall include protective measures and be suitable for installations designed to be in
392 accordance with IEC 60364-7-704:2017
393 8.4.4 Additional requirements for class II assemblies
394 e) This item of P
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