EN IEC 61558-2-14:2025

SLOVENSKI STANDARD
01-maj-2025
Nadomešča:
SIST EN 61558-2-14:2013
Varnost transformatorjev, dušilk, napajalnikov in kombinacij teh elementov - 2-14.
del: Posebne zahteve in preskusi za spremenljive transformatorje in napajalnike z
vgrajenimi spremenljivimi transformatorji
Safety of transformers, reactors, power supply units and combinations thereof - Part 2-
14: Particular requirements and tests for variable transformers and power supply units
incorporating variable transformers for general applications
Sicherheit von Transformatoren, Drosseln, Netzgeräten und deren Kombinationen - Teil
2-14: Besondere Anforderungen und Prüfungen für Stelltransformatoren und Netzgeräte,
die Stelltransformatoren enthalten
Sécurité des transformateurs, bobines d'inductance, blocs d'alimentation et des
combinaisons de ces éléments - Partie 2-14: Exigences particulières et essais pour les
transformateurs variables et les blocs d'alimentation incorporant des transformateurs
variables
Ta slovenski standard je istoveten z: EN IEC 61558-2-14:2025
ICS:
29.180 Transformatorji. Dušilke Transformers. Reactors
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPÄISCHE NORM EN IEC 61558-2-14

EUROPEAN STANDARD
NORME EUROPÉENNE
März 2025
ICS 29.180 Ersetzt EN 61558-2-14:2013
Deutsche Fassung
Sicherheit von Transformatoren, Drosseln, Netzgeräten und
deren Kombinationen - Teil 2-14: Besondere Anforderungen und
Prüfungen für Stelltransformatoren und Netzgeräte, die
Stelltransformatoren enthalten
(IEC 61558-2-14:2022)
Safety of transformers, reactors, power supply units and Sécurité des transformateurs, bobines d'inductance, blocs
combinations thereof - Part 2-14: Particular requirements d'alimentation et des combinaisons de ces éléments -
and tests for variable transformers and power supply units Partie 2-14: Exigences particulières et essais pour les
incorporating variable transformers for general applications transformateurs variables et les blocs d'alimentation
(IEC 61558-2-14:2022) incorporant des transformateurs variables pour applications
générales
(IEC 61558-2-14:2022)
Diese Europäische Norm wurde von CENELEC am 2024-10-16 angenommen. CENELEC-Mitglieder sind gehalten, die CEN/CENELEC-
Geschäftsordnung zu erfüllen, in der die Bedingungen festgelegt sind, unter denen dieser Europäischen Norm ohne jede Änderung der
Status einer nationalen Norm zu geben ist.
Auf dem letzten Stand befindliche Listen dieser nationalen Normen mit ihren bibliographischen Angaben sind beim CEN-CENELEC
Management Centre oder bei jedem CENELEC-Mitglied auf Anfrage erhältlich.
Diese Europäische Norm besteht in drei offiziellen Fassungen (Deutsch, Englisch, Französisch). Eine Fassung in einer anderen Sprache,
die von einem CENELEC-Mitglied in eigener Verantwortung durch Übersetzung in seine Landessprache gemacht und dem CEN-CENELEC
Management Centre mitgeteilt worden ist, hat den gleichen Status wie die offiziellen Fassungen.
CENELEC-Mitglieder sind die nationalen elektrotechnischen Komitees von Belgien, Bulgarien, Dänemark, Deutschland, Estland, Finnland,
Frankreich, Griechenland, Irland, Island, Italien, Kroatien, Lettland, Litauen, Luxemburg, Malta, den Niederlanden, Norwegen, Österreich,
Polen, Portugal, der Republik Nordmazedonien, Rumänien, Schweden, der Schweiz, Serbien, der Slowakei, Slowenien, Spanien, der
Tschechischen Republik, der Türkei, Ungarn, dem Vereinigten Königreich und Zypern.

Europäisches Komitee für Elektrotechnische Normung
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CENELEC Alle Rechte der Verwertung, gleich in welcher Form und in welchem Verfahren, sind weltweit den Mitgliedern von
CENELEC vorbehalten.
Ref. Nr. EN IEC 61558-2-14:2025 D

European foreword
The text of document 96/507/CDV, future edition 2 of IEC 61558-2-14, prepared by TC 96
"Transformers, reactors, power supply units, and combinations thereof" was submitted to the IEC-
CENELEC parallel vote and approved by CENELEC as EN IEC 61558-2-14:2025.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2026-03-31
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2028-03-31
document have to be withdrawn
This document supersedes EN 61558-2-14:2013 and all of its amendments and corrigenda (if any).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
This document is read in conjunction with EN IEC 61558-1:2019.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 61558-2-14:2022 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 standard indicated:
IEC 60076-11:2018 NOTE Approved as EN IEC 60076-11:2018 (not modified)
IEC 61558 series NOTE Approved as EN 61558 series
IEC 60204-1:2016 NOTE Approved as EN 60204-1:2018
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments)
applies.
NOTE 1  Where an International Publication has been modified by common modifications, indicated by (mod),
the relevant EN/HD applies.
NOTE 2  Up-to-date information on the latest versions of the European Standards listed in this annex is available
here: www.cencenelec.eu.
Annex ZA of EN IEC 61558-1 is applicable, except as follows:
Add:
Publication Year Title EN/HD Year
IEC 61558-1 2017 Safety of transformers, reactors, power EN IEC 61558-1 2019
supply units and combinations thereof -
Part 1: General requirements and tests

IEC 61558-2-14 ®
Edition 2.0 2022-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
GROUP SAFETY PUBLICATION
PUBLICATION GROUPÉE DE SÉCURITÉ

Safety of transformers, reactors, power supply units and combinations thereof –
Part 2-14: Particular requirements and tests for variable transformers and power
supply units incorporating variable transformers for general applications
Sécurité des transformateurs, bobines d’inductance, blocs d'alimentation et des
combinaisons de ces éléments –
Partie 2-14: Exigences particulières et essais pour les transformateurs variables
et les blocs d'alimentation incorporant des transformateurs variables pour
applications générales
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.180 ISBN 978-2-8322-5039-6
– 2 – IEC 61558-2-14:2022  IEC 2022
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 8
3 Terms and definitions . 8
4 General requirements . 9
5 General notes on tests . 9
6 Ratings . 9
7 Classification . 10
8 Marking and other information . 10
9 Protection against electric shock . 12
10 Change of input voltage setting . 12
11 Output voltage and output current under load . 12
12 No-load output voltage . 12
13 Short-circuit voltage . 14
14 Heating . 15
15 Short-circuit and overload protection . 15
16 Mechanical strength . 15
17 Protection against harmful ingress of dust, solid objects and moisture . 16
18 Insulation resistance, dielectric strength and leakage current . 16
19 Construction . 16
20 Components . 16
21 Internal wiring . 16
22 Supply connection and other external flexible cables or cords . 16
23 Terminals for external conductors . 17
24 Provisions for protective earthing. 17
25 Screws and connections . 17
26 Creepage distances, clearances and distances through insulation . 17
27 Resistance to heat, fire and tracking . 17
28 Resistance to rusting . 17
Annexes . 18
Bibliography . 19

Table 101 – Symbols indicating the kind of transformer . 11
Table 102 – Output voltage ratio for auto-transformers, separating transformers and
safety isolating transformers . 14
Table 103 – Output voltage ratio for isolating transformers . 14
Table 104 – Maximum permitted temperatures of the winding . 15

IEC 61558-2-14:2022  IEC 2022 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SAFETY OF TRANSFORMERS, REACTORS, POWER
SUPPLY UNITS AND COMBINATIONS THEREOF –

Part 2-14: Particular requirements and tests for variable
transformers and power supply units incorporating
variable transformers for general applications

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.
IEC 61558-2-14 has been prepared by IEC technical committee 96: Transformers, reactors,
power supply units and combinations thereof. It is an International standard.
This second edition cancels and replaces the first edition published in 2012. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) adjustment of structure and references in accordance with IEC 61558-1:2017;
b) description of constructions moved to IEC 61558-1:2017;
c) new symbols for power supply units with linearly regulated output voltages and required
current collector position changes.

– 4 – IEC 61558-2-14:2022  IEC 2022
The text of this International standard is based on the following documents:
Draft Report on voting
96/507/CDV 96/528/RVC
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.
It has the status of a group safety publication in accordance with IEC Guide 104.
This International Standard is to be used in conjunction with IEC 61558-1:2017.
NOTE When "Part 1" is mentioned in this standard, it refers to IEC 61558-1:2017.
This document supplements or modifies the corresponding clauses in IEC 61558-1:2017, so as
to convert that publication into the IEC standard: Particular requirements and tests for variable
transformers and power supply units incorporating variable transformers for general
applications.
A list of all parts in the IEC 61558 series, published 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 this document states "addition", "modification" or "replacement", the relevant text of
IEC 61558-1:2017 is to be adapted accordingly.
In this document, 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 document, the words in bold are defined in Clause 3.
Subclauses, notes, figures and tables additional to those in IEC 61558-1:2017 are numbered
starting from 101; supplementary annexes are entitled AA, BB, etc.
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,
• replaced by a revised edition, or
• amended.
IEC 61558-2-14:2022  IEC 2022 – 5 –
INTRODUCTION
IEC TC 96 has a group safety function in accordance with IEC Guide 104 for transformers other
than those intended to supply distribution networks, in particular transformers and power
supply units intended to allow the application of protective measures against electric shock as
defined by TC 64, but in certain cases including limitation of voltage and horizontal safety
function for SELV in accordance with IEC 60364-4-41.
The group safety function (GSF) is necessary because of responsibility e.g. for safety extra-low
voltage (SELV) in accordance with IEC 61140:2016, 5.2.6 and IEC 60364-4-41:2005, 414.3.1
or control circuits in accordance with IEC 60204-1:2016, 7.2.4.
The group safety function is needed for each part of IEC 61558-2 because different standards
of the IEC 61558 series can be combined in one construction but in certain cases with no
limitation of rated output power.
For example an auto-transformer in accordance with IEC 61558-2-13 can be designed with a
separate SELV-circuit in accordance with the particular requirements for IEC 61558-2-6 relating
to the general requirements of IEC 61558-1.

– 6 – IEC 61558-2-14:2022  IEC 2022
SAFETY OF TRANSFORMERS, REACTORS, POWER
SUPPLY UNITS AND COMBINATIONS THEREOF –

Part 2-14: Particular requirements and tests for variable
transformers and power supply units incorporating
variable transformers for general applications

1 Scope
Replacement
This part of IEC 61558 deals with the safety of variable transformers for general applications
and power supply units incorporating variable transformers for general applications.
Transformers incorporating electronic circuits are also covered by this document.
NOTE 1 Safety includes electrical, thermal, mechanical and chemical aspects.
Unless otherwise specified, from here onward, the term transformer covers variable
transformers for general applications and power supply units incorporating variable
transformers for general applications.
For power supply units (linear) this document is applicable. For switch mode power supply
units, IEC 61558-2-16 is applicable together with this document. Where two requirements are
in conflict, the most severe take precedence.
This document does not apply to transformers covered by IEC 60076-11.
This document is applicable to stationary or portable, single-phase or polyphase, air-cooled
(natural or forced) independent or associated variable dry-type transformers:
– variable auto-transformers;
– variable separating transformers;
– variable isolating transformers;
– variable safety isolating transformers.
The windings can be encapsulated or non-encapsulated.
The rated supply voltage does not exceed 1 000 V AC and the rated supply frequency and
the internal operational frequencies do not exceed 500 Hz.
The rated output does not exceed:
– 40 kVA for single-phase variable auto-transformers;
– 200 kVA for polyphase variable auto-transformers;
– 1 kVA for single-phase variable separating transformers;
– 5 kVA for polyphase variable separating transformers;
– 25 kVA for single-phase variable isolating transformers;
– 40 kVA for polyphase variable isolating transformers;
– 10 kVA for single-phase variable safety isolating transformers;
– 16 kVA for polyphase variable safety isolating transformers.
This document is applicable to variable transformers without limitation of the rated output
subject to an agreement between the purchaser and the manufacturer.
NOTE 2 Tra
...