SIST EN 61558-2-23:2010

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 (IEC 61558-2-23:2010)

IEC 61558-2-23:2010 deals with the safety of transformers for construction sites and power supply units incorporating transformers for construction sites. Transformers incorporating electronic circuits are also covered by this standard. This second edition cancels and replaces the first edition published in 2000. It constitutes a technical revision. The main changes consist of updating this Part 2-23 in accordance with IEC 61558-1:2005. This part has the status of a group safety publication in accordance with IEC Guide 104: The preparation of safety publications and the use of basic safety publications and group safety publications. The attention of National Committees is drawn to the fact that equipment manufacturers and testing organizations may need a transitional period following publication of a new, amended or revised IEC publication in which to make products in accordance with the new requirements and to equip themselves for conducting new or revised tests. It is the recommendation of the committee that the content of this publication be adopted for implementation nationally not earlier than 12 months from the date of publication. In the meantime, the previous edition can still be ordered by contacting your local IEC member National Committee or the IEC Central Office.

Sicherheit von Transformatoren, Drosseln, Netzgeräten und entsprechenden Kombinationen - Teil 2-23: Besondere Anforderungen und Prüfungen für Transformatoren und Netzgeräte für Baustellen (IEC 61558-2-23:2010)

Sécurité des transformateurs, bobines d'inductance, blocs d'alimentation et des combinaisons de ces éléments - Partie 2-23: Règles particulières et essais pour les transformateurs et les blocs d'alimentation pour chantiers (CEI 61558-2-23:2010)

La CEI 61558-2-23:2010 traite de la sécurité des transformateurs pour chantiers et des blocs d'alimentation incorporant des transformateurs pour chantiers. Les transformateurs incorporant des circuits électroniques sont également couverts par la présente norme. Cette deuxième édition annule et remplace la première édition publiée en 2000. Elle constitue une révision technique. Les principales modifications consistent en la mise à jour de la présente partie conformément à la CEI 61558-1:2005. La présente partie a le statut de publication groupée de sécurité conformément au Guide CEI 104: Élaboration des publications de sécurité et utilisation des publications fondamentales de sécurité et publications groupées de sécurité. L'attention des Comités Nationaux est attirée sur le fait que les fabricants des appareils et les organismes d'essai peuvent avoir besoin d'une période transitoire, à la parution d'une publication CEI qu'elle soit nouvelle, modifiée ou révisée, pour mettre les produits en conformité avec les nouvelles exigences et pour s'équiper eux-mêmes afin de réaliser de nouveaux essais ou des essais révisés. Le comité recommande que le contenu de la présente publication soit adopté pour mise en oeuvre au niveau national au plus tôt 12 mois après la date de publication. Pendant ce temps, l'édition précédente peut toujours être commandée auprès du Comité National CEI de votre pays ou auprès du bureau Central de la CEI.

Varnost transformatorjev, dušilk, napajalnikov in kombinacij teh elementov - 2-23. del: Posebne zahteve in preskusi za transformatorje in napajalnike za gradbišča (IEC 61558-2-23:2010)

Ta del IEC 61558 obravnava varnost transformatorjev za gradbišča in napajalnikov, ki vsebujejo transformatorje, za gradbišča. Transformatorji, ki vsebujejo elektronska vezja, so prav tako zajeti v tem standardu. Razen če je drugače navedeno, v nadaljevanju izraz transformator zajema  transformatorje za gradbišča in napajalnike, ki vsebujejo transformatorje za gradbišča. Ta del velja za nepremične ali prenosne, enofazne ali večfazne, zračno hlajene (naravno ali vsiljeno), samostojne ali povezane transformatorje, ki so ločilni ali varnostno ločilni transformatorji suhega tipa za uporabo na gradbiščih. Navitje je lahko inkapsulirano ali nekapsulirano. Nazivna napetost napajanja ne presega 1.000 V izmeničnega toka in nazivna frekvenca napajanja in notranja obratovalna frekvenca ne presega 500 Hz. Ta standard v kombinaciji z delom 2-16 za stikalni napajalnik (SMPS) velja tudi za napajalnike z notranjimi obratovalnimi frekvencami, višjimi od 500 Hz. Če sta zahtevi v nasprotju, ima prednost najstrožja. Nazivni izhod ne presega: - 25 kVA za enofazne transformatorje; - 40 kVA za večfazne transformatorje. Ta del velja za transformatorje brez omejitve nazivnega izhoda, ki je predmet dogovora med kupcem in proizvajalcem. Ločilni transformatorji in napajalniki, ki vsebujejo ločilne transformatorje za gradbišča, imajo izhodno napetost v prostem teku in nazivno izhodno napetost, ki presega 50 V izmeničnega toka in ne presega 250 V izmeničnega toka. Varnostni ločilni transformatorji in napajalniki, ki vsebujejo varnostne ločilne transformatorje, za gradbišča, imajo izhodno napetost v prostem teku in nazivno izhodno napetost, ki ne presega 50 V izmeničnega toka. Transformatorji in napajalniki, ki jih zajema ta del, se uporabljajo v napravah, kjer to zahtevajo pravila za namestitev ali specifikacije naprave, z namenom zaščite. Kadar so transformatorji ali napajalniki vgrajeni v nizkonapetostne stikalne in krmilne naprave za gradbišča, kot je opredeljeno v IEC 60439-4, se za sklop uporabljajo dodatne zahteve IEC 60439-4.

General Information

• Status: Published
• Publication Date: 14-Nov-2010
• ICS: 29.180 - Transformers. Reactors
• ICS: 91.200 - Construction technology
• Technical Committee: I96 - Imaginarni 96
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 29-Oct-2010
• Due Date: 03-Jan-2011
• Completion Date: 15-Nov-2010
• Directive: 2006/95/EC - Directive 2006/95/EC of the European Parliament and of the Council of 12 December 2006 on the harmonisation of the laws of Member States relating to electrical equipment designed for use within certain voltage limits (codified version)
• 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
• Ref Project: EN 61558-2-23:2010 - 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

Relations

• Replaces: SIST EN 61558-2-23:2001 - Safety of power transformers, power supply units and similar devices -- Part 2-23: Particular requirements for transformers for construction sites
• Effective Date: 01-Oct-2013
• Replaced By: SIST 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: 01-May-2025
• Revised: SIST EN 61558-2-23:2001 - Safety of power transformers, power supply units and similar devices -- Part 2-23: Particular requirements for transformers for construction sites
• Effective Date: 08-Oct-2013

Overview

EN 61558-2-23:2010 (IEC 61558-2-23:2010) specifies particular safety requirements and tests for transformers and power supply units used on construction sites. It applies to transformers and power supply units (including those that incorporate electronic circuits) intended for use in temporary and rugged site environments. This second edition (2010) supersedes the 2000 edition and updates Part 2-23 in line with IEC/EN 61558-1:2005. The standard is a group safety publication (IEC Guide 104) and is intended to be used together with EN/IEC 61558-1.

Keywords: EN 61558-2-23, IEC 61558-2-23, transformers for construction sites, power supply units, safety requirements, testing.

Key Topics

EN 61558-2-23 supplements EN/IEC 61558-1 by setting construction-site-specific requirements and test criteria. Major topics covered include:

• Scope and definitions for construction-site transformers and PSUs (including devices with electronic circuitry).
• General requirements and ratings (intended use, rated voltages/currents, low-voltage applications up to 1 100 V).
• Performance tests and routine tests - test methods and production checks for safety verification.
• Electrical safety: protection against electric shock, insulation resistance, dielectric strength, leakage current.
• Voltage behaviour: change of input-voltage setting, output voltage/current under load, no-load output and short-circuit voltage.
• Thermal and overload safety: heating limits, short-circuit and overload protection.
• Mechanical robustness: mechanical strength, impact tests, resistance to rusting and environmental stress.
• Ingress protection and wiring: protection against dust/moisture, internal wiring, supply connections, terminals and earthing provisions.
• Clearances, creepage distances and fire resistance: requirements to reduce tracking, fire and heat risks.
• Marking and documentation: required markings, user information and classification for construction environments.

Applications

This standard is specifically targeted at equipment for temporary power distribution and portable power supplies on building and civil-engineering sites. Typical applications:

• Portable and site-use isolating/safety transformers
• Power supply units used for site lighting, tools and distribution boards
• Transformers incorporated into site distribution assemblies and equipment enclosures

Who should use this standard

• Manufacturers designing construction-site transformers and PSUs (including electronic-including designs)
• Test laboratories and certification bodies performing conformity assessment and type testing
• Procurement and safety managers specifying safe temporary power equipment for construction projects
• Design engineers responsible for mechanical and electrical protection in rugged environments

Related standards

• EN/IEC 61558-1: General requirements and tests (mandatory companion document)
• IEC 60364-7-704 / EN 60364-7-704: Site electrical installations
• EN 61558-2-16 and other parts of EN 61558 series for related transformer types
• IEC 60068-2-27 (environmental shock testing) and EN 60439-4 (site switchgear assemblies) - referenced for specific tests and assemblies

Note: EN 61558-2-23:2010 recommends a transitional adoption period (typical national implementation not earlier than 12 months after publication) to allow manufacturers and testing organizations to adapt to revised requirements.

Standards Content (Sample)

SLOVENSKI STANDARD
01-december-2010
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SIST EN 61558-2-23:2001
9DUQRVWWUDQVIRUPDWRUMHYGXãLONQDSDMDOQLNRYLQNRPELQDFLMWHKHOHPHQWRY
GHO3RVHEQH]DKWHYHLQSUHVNXVL]DWUDQVIRUPDWRUMHLQQDSDMDOQLNH]DJUDGELãþD
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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 (IEC 61558-2-23:2010)
Sicherheit von Transformatoren, Drosseln, Netzgeräten und entsprechenden
Kombinationen - Teil 2-23: Besondere Anforderungen und Prüfungen für
Transformatoren und Netzgeräte für Baustellen (IEC 61558-2-23:2010)
Sécurité des transformateurs, bobines d'inductance, blocs d'alimentation et des
combinaisons de ces éléments - Partie 2-23: Règles particulières et essais pour les
transformateurs et les blocs d'alimentation pour chantiers (CEI 61558-2-23:2010)
Ta slovenski standard je istoveten z: EN 61558-2-23:2010
ICS:
29.180 Transformatorji. Dušilke Transformers. Reactors
91.200 Gradbena tehnologija Construction technology
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 61558-2-23
NORME EUROPÉENNE
October 2010
EUROPÄISCHE NORM
ICS 29.180 Supersedes EN 61558-2-23:2000

English version
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
(IEC 61558-2-23:2010)
Sécurité des transformateurs, bobines Sicherheit von Transformatoren, Drosseln,
d'inductance, blocs d'alimentation et des Netzgeräten und entsprechenden
combinaisons de ces éléments - Kombinationen -
Partie 2-23: Règles particulières et essais Teil 2-23: Besondere Anforderungen und
pour les transformateurs et les blocs Prüfungen für Transformatoren und
d'alimentation pour chantiers Netzgeräte für Baustellen
(CEI 61558-2-23:2010) (IEC 61558-2-23:2010)

This European Standard was approved by CENELEC on 2010-10-01. CENELEC members are bound to comply
with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard
the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and notified
to the Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus,
the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia,
Spain, Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Management Centre: Avenue Marnix 17, B - 1000 Brussels

© 2010 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 61558-2-23:2010 E
Foreword
The text of document 96/359/FDIS, future edition 2 of IEC 61558-2-23, prepared by IEC TC 96,
Transformers, reactors, power supply units and similar products for low voltage up to 1 100 V, was
submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 61558-2-23 on
2010-10-01.
This European Standard supersedes EN 61558-2-23:2000.
The main changes consist of updating this Part 2-23 in accordance with EN 61558-1:2005.
This part is intended to be used in conjunction with the latest edition of EN 61558-1 and its amendments.
It is based on EN 61558-1:2005.
This part supplements or modifies the corresponding clauses in EN 61558-1, so as to convert that
publication into the standard: Particular requirements and tests for transformers and power supply units
for construction sites.
Future standards in this series will carry the new general title as cited above. Titles of existing standards
in this series will be updated at the time of the next edition.
Where a particular subclause of Part 1 is not mentioned in this part, that subclause applies as far as is
reasonable. Where this part states "addition", "modification" or "replacement", the relevant text of Part 1 is
to be adapted accordingly.
In this part, the following print types are used:
– requirements proper: in roman type;
– test specifications: in italic type;
– explanatory matter: in smaller roman type.
In the text of this part, the words in bold are defined in Clause 3.
Subclauses, notes, figures and tables additional to those in Part 1 are numbered starting from 101;
supplementary annexes are entitled AA, BB, etc.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN and CENELEC shall not be held responsible for identifying any or all such patent
rights.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
(dop) 2011-07-01
national standard or by endorsement
– latest date by which the national standards conflicting
(dow) 2013-10-01
with the EN have to be withdrawn
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 61558-2-23:2010 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:

- 3 - EN 61558-2-23:2010
IEC 60364-7-704:2005 NOTE  Harmonized as EN 60364-7-704:2007 (modified).
IEC 61558-2-16:2009 NOTE  Harmonized as EN 61558-2-16:2009 (not modified).

Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.

NOTE  When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.
Annex ZA of Part 1 is applicable except as follows:

Addition:
Publication Year Title EN/HD Year

IEC 60068-2-27 - Environmental testing - EN 60068-2-27 -
Part 2-27: Tests - Test Ea and guidance:
Shock
IEC 60439-4 - Low-voltage switchgear and controlgear EN 60439-4 -
assemblies -
Part 4: Particular requirements for assemblies
for construction sites (ACS)
IEC 61558-1 2005 Safety of power transformers, power supplies, EN 61558-1 2005
reactors and similar products - + corr. August 2006
Part 1: General requirements and tests

IEC 61558-2-23 ®
Edition 2.0 2010-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
GROUP SAFETY PUBLICATION
PUBLICATION GROUPÉE DE SÉCURITÉ

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
Sécurité des transformateurs, bobines d’inductance, blocs d'alimentation et des
combinaisons de ces élements –
Partie 2-23: Règles particulières et essais pour les transformateurs et les blocs
d'alimentation pour chantiers
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
S
CODE PRIX
ICS 29.180 ISBN 978-2-88912-162-5
– 2 – 61558-2-23 © IEC:2010
CONTENTS
FOREWORD.3
1 Scope.5
2 Normative references.6
3 Terms and definitions .6
4 General requirements .6
5 General notes on tests.7
6 Ratings.7
7 Classification .8
8 Marking and other information.8
9 Protection against electric shock.10
10 Change of input voltage setting .10
11 Output voltage and output current under load .10
12 No-load output voltage.10
13 Short-circuit voltage.11
14 Heating.11
15 Short-circuit and overload protection .12
16 Mechanical strength.12
17 Protection against harmful ingress of dust, solid objects and moisture.13
18 Insulation resistance, dielectric strength and leakage current .13
19 Construction .13
20 Components .16
21 Internal wiring .16
22 Supply connection and other external flexible cable or cords .16
23 Terminals for external conductors .16
24 Provisions for protective earthing .16
25 Screws and connections .16
26 Creepage distances, clearances and distances through insulation .17
27 Resistance to heat, fire and tracking .17
28 Resistance to rusting .17
Annexes.19
Annex L Routine tests (production tests) .19
Bibliography .20

Figure 101 – Impact test for horizontal surface .18
Figure 102 – Impact test for vertical surface .18

Table 101 – Ratio of output voltages for safety isolating transformers .11
Table 102 – Ratio of output voltages for isolating transformers .11

61558-2-23 © IEC:2010 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
_____________
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

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) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61558-2-23 has been prepared by IEC Technical Committee 96:
Transformers, reactors, power supply units, and combinations thereof.
This second edition cancels and replaces the first edition published in 2000. It constitutes a
technical revision. The main changes consist of updating this Part 2-23 in accordance with
IEC 61558-1:2005.
This part has the status of a group safety publication in accordance with IEC Guide 104: The
preparation of safety publications and the use of basic safety publications and group safety
publications.
– 4 – 61558-2-23 © IEC:2010
The text of this standard is based on the following documents:
FDIS Report on voting
96/359/FDIS 96/368/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
This part is intended to be used in conjunction with the latest edition of IEC 61558-1 and its
amendments. It is based on the second edition (2005) of that standard.
This part supplements or modifies the corresponding clauses in IEC 61558-1, so as to convert
that publication into the IEC standard: Particular requirements and tests for transformers and
power supply units for construction sites.
A list of all parts of the IEC 61558 series, under the general title: Safety of transformers,
reactors, power supply units and combinations thereof, can be found on the IEC website.
Future standards in this series will carry the new general title as cited above. Titles of existing
standards in this series will be updated at the time of the next edition.
Where a particular subclause of Part 1 is not mentioned in this part, that subclause applies as
far as is reasonable. Where this part states "addition", "modification" or "replacement", the
relevant text of Part 1 is to be adapted accordingly.
In this part, the following print types are used:
– requirements proper: in roman type;
– test specifications: in italic type;
– explanatory matter: in smaller roman type.
In the text of this part, the words in bold are defined in Clause 3.
Subclauses, notes, figures and tables additional to those in Part 1 are numbered starting from
101; supplementary annexes are entitled AA, BB, etc.
The committee has decided that the contents of this publication will remain unchanged until the
stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data related to
the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
NOTE The attention of National Committees is drawn to the fact that equipment manufacturers and testing
organizations may need a transitional period following publication of a new, amended or revised IEC publication in
which to make products in accordance with the new requirements and to equip themselves for conducting new or
revised tests.
It is the recommendation of the committee that the content of this publication be adopted for implementation
nationally not earlier than 12 months from the date of publication.

61558-2-23 © IEC:2010 – 5 –
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

1 Scope
Replacement:
This part of IEC 61558 deals with the safety of transformers for construction sites and
power supply units incorporating transformers for construction sites. Transformers
incorporating electronic circuits are also covered by this standard.
NOTE 1 Safety includes electrical, thermal and mechanical aspects.
Unless otherwise specified, from here onward, the term transformer covers transformers for
construction sites and power supply units incorporating transformers for construction
sites.
This part is applicable to stationary or portable, single-phase or polyphase, air-cooled (natural
or forced) independent or associated transformers, being isolating or safety isolating dry-
type transformers for the use on construction sites. The windings may be encapsulated or
non-encapsulated.
The rated supply voltage does not exceed 1 000 V a.c., and the rated supply frequency and
the internal operating frequencies do not exceed 500 Hz.
This standard used in combination with Part 2-16 for Switch mode power supply units
(SMPS) is also applicable to power supplies with internal operating frequencies higher than
500 Hz. Where the two requirements are in conflict the most severe take precedence
The rated output does not exceed:
– 25 kVA for single-phase transformers;
– 40 kVA for poly-phase transformers.
This part is applicable to transformers without limitation of the rated output subject to an
agreement between the purchaser and the manufacturer.
NOTE 2 Transformers intended to supply distribution networks are not included in the scope.
Isolating transformers and power supply units incorporating isolating transformers for
construction sites have a no-load output voltage and a rated output voltage exceeding 50
V a.c. and not exceeding 250 V a.c.
Safety isolating transformers and power supply units incorporating safety isolating
transformers for construction sites have a no-load output voltage and a rated output
voltage not exceeding 50 V a.c.
NOTE 3 This standard is applicable to transformers for the supply of electricity in locations as specified in
IEC 60364-7-704. The latter also specifies the protection by using an earthed midpoint or starpoint of the output
winding.
– 6 – 61558-2-23 © IEC:2010
Transformers and power supply units covered by this part are used in applications where it
is required by the installation rules or by the appliance specification for protection purposes.
When the transformers or power supply units are incorporated into low voltage switchgear
and controlgear assemblies for construction sites as specified in IEC 60439-4, the
additional requirements of IEC 60439-4 will apply to the assembly.
NOTE 4 For transformers filled with liquid dielectric or pulverised material, such as sand, additional requirements
are under consideration.
NOTE 5 Attention is drawn to the following:
– measures to protect the enclosure and the components inside the enclosure against external influences
like fungus, vermin, termites, solar-radiation and icing should also be considered;
– the different conditions for transportation, storage, and operation of the transformers and power supply
units should also be considered;
– additional requirements in accordance with other appropriate standards and national rules may be
applicable to transformers and power supply units intended for use in special environments such as
tropical environment.
NOTE 6 Future technological development of transformers may necessitate a need to increase the upper limit of
the frequencies, until then this standard may be used as a guidance document.
2 Normative references
This clause of Part 1 is applicable except as follows:
Addition:
IEC 60068-2-27, Environmental testing – Part 2-27: Tests – Test Ea and guidance: Shock
IEC 60439-4, Low-voltage switchgear and controlgear assemblies – Part 4: Particular
requirements for assemblies for construction sites (ACS)
IEC 61558-1:2005, Safety of power transformers, power supplies, reactors and similar products
– Part 1: General requirements and tests
3 Terms and definitions
This clause of Part 1 is applicable except as follows:
Addition:
3.101
low voltage switchgear and controlgear assembly for construction sites (ACS)
combination
...