IEC 61558-2-13:2022
(Main)Safety of transformers, reactors, power supply units and combinations thereof - Part 2-13: Particular requirements and tests for auto-transformers and power supply units incorporating auto-transformers for general applications
Safety of transformers, reactors, power supply units and combinations thereof - Part 2-13: Particular requirements and tests for auto-transformers and power supply units incorporating auto-transformers for general applications
IEC 61558-2-13:2022 deals with the safety of auto-transformers for general applications and power supply units incorporating auto-transformers for general applications. Transformers incorporating electronic circuits are also covered by this document. This third edition cancels and replaces the second edition published in 2009. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
- adjustment of structure and references in accordance with IEC 61558-1:2017;
- description of constructions moved to IEC 61558-1:2017;
- new symbol for power supply unit with linearly regulated output voltage.
It has the status of a group safety publication in accordance with IEC Guide 104.
Sécurité des transformateurs, bobines d'inductance, blocs d'alimentation et combinaisons de ces éléments - Partie 2-13: Exigences particulières et essais pour les autotransformateurs et les blocs d'alimentation qui incorporent des autotransformateurs pour applications d'ordre général
L'IEC 61558-2-13:2022 traite de la sécurité des autotransformateurs pour applications d'ordre général et des blocs d'alimentation qui incorporent des autotransformateurs pour applications d'ordre général. Les transformateurs qui incorporent des circuits électroniques sont également couverts par le présent document. Cette troisième édition annule et remplace la deuxième édition parue en 2009. Cette édition constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
- la structure et les références ont été alignées sur l'IEC 61558-1:2017;
- la description des constructions a été déplacée dans l'IEC 61558-1:2017;
- un nouveau symbole a été ajouté pour les blocs d'alimentation dont la régulation de la tension secondaire est linéaire.
Il a le statut de publication groupée de sécurité conformément au Guide 104 de l'IEC.
General Information
Relations
Standards Content (Sample)
IEC 61558-2-13 ®
Edition 3.0 2022-10
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
GROUP SAFETY PUBLICATION
Safety of transformers, reactors, power supply units and similar products for
supply voltages up to 1 100 V combinations thereof –
Part 2-13: Particular requirements and tests for auto-transformers and power
supply units incorporating auto-transformers for general applications
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.
IEC Secretariat Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.
About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.
IEC publications search - webstore.iec.ch/advsearchform IEC Products & Services Portal - products.iec.ch
The advanced search enables to find IEC publications by a Discover our powerful search engine and read freely all the
variety of criteria (reference number, text, technical publications previews. With a subscription you will always
committee, …). It also gives information on projects, replaced have access to up to date content tailored to your needs.
and withdrawn publications.
Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished
The world's leading online dictionary on electrotechnology,
Stay up to date on all new IEC publications. Just Published
containing more than 22 300 terminological entries in English
details all new publications released. Available online and
and French, with equivalent terms in 19 additional languages.
once a month by email.
Also known as the International Electrotechnical Vocabulary
(IEV) online.
IEC Customer Service Centre - webstore.iec.ch/csc
If you wish to give us your feedback on this publication or
need further assistance, please contact the Customer Service
Centre: sales@iec.ch.
IEC 61558-2-13 ®
Edition 3.0 2022-10
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
GROUP SAFETY PUBLICATION
Safety of transformers, reactors, power supply units and similar products for
supply voltages up to 1 100 V combinations thereof –
Part 2-13: Particular requirements and tests for auto-transformers and power
supply units incorporating auto-transformers for general applications
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.180 ISBN 978-2-8322-5925-2
– 2 – IEC 61558-2-13:2022 RLV IEC 2022
CONTENTS
FOREWORD . 3
INTRODUCTION . 6
1 Scope . 7
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 . 13
14 Heating . 13
15 Short-circuit and overload protection . 13
16 Mechanical strength . 13
17 Protection against harmful ingress of dust, solid objects and moisture . 13
18 Insulation resistance, dielectric strength and leakage current . 13
19 Construction . 14
20 Components . 15
21 Internal wiring . 15
22 Supply connection and other external flexible cable or cords . 15
23 Terminals for external conductors . 15
24 Provisions for protective earthing. 15
25 Screws and connections . 15
26 Creepage distances, clearances and distances through insulation . 15
27 Resistance to heat, fire and tracking . 16
28 Resistance to rusting . 16
Annexes . 17
Bibliography . 18
Figure 101 – Windings . 9
Figure 102 – Tappings . 9
Figure 103 – Windings separated by functional isolation . 9
Table 101 – Symbols indicating the kind of transformer . 11
Table 101 102 – Output voltage difference ratio . 13
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SAFETY OF TRANSFORMERS, REACTORS, POWER
SUPPLY UNITS AND SIMILAR PRODUCTS FOR SUPPLY VOLTAGES UP TO
1 100 V COMBINATIONS THEREOF –
Part 2-13: Particular requirements and tests for
auto-transformers and power supply units incorporating
auto-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.
This redline version of the official IEC Standard allows the user to identify the changes made to
the previous edition IEC 61558-2-13:2009. 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 61558-2-13:2022 RLV IEC 2022
International standard IEC 61558-2-13 has been prepared by IEC technical committee 96:
Transformers, reactors, power supply units and combinations thereof.
This third edition cancels and replaces the second edition published in 2009. 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 symbol for power supply unit with linearly regulated output voltage.
The text of this document is based on the following documents:
Draft Report on voting
96/549/FDIS 96/555/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/standardsdev/publications.
It has the status of a group safety publication in accordance with IEC Guide 104.
This document is to be used in conjunction with 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 auto-
transformers and power supply units incorporating auto-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 a particular subclause of IEC 61558-1:2017 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 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 "http://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.
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 61558-2-13:2022 RLV IEC 2022
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 the limitation of voltage and horizontal safety function
for SELV, in accordance with IEC 60364-4-41.
The group safety function (GSF) is used because of responsibility for example 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 used 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.
SAFETY OF TRANSFORMERS, REACTORS, POWER
SUPPLY UNITS AND SIMILAR PRODUCTS FOR SUPPLY VOLTAGES UP TO
1 100 V COMBINATIONS THEREOF –
Part 2-13: Particular requirements and tests for
auto-transformers and power supply units incorporating
auto-transformers for general applications
1 Scope
Replacement:
This part of IEC 61558 deals with the safety of auto-transformers for general applications and
power supply units incorporating auto-transformers for general applications. Transformers
incorporating electronic circuits are also covered by this document.
NOTE 1 Safety includes electrical, thermal and mechanical aspects.
Unless otherwise specified, from here onward, the term transformer covers auto-transformers
for general applications and power supply units incorporating auto-transformers for general
applications.
NOTE 2 For power supply units (linear) this document is applicable. For switch mode power
supply units IEC 61558-2-16 is applicable together with this part.
This document is applicable to stationary or portable, single-phase or polyphase, air-cooled
(natural or forced) independent or associated dry-type transformers. The windings may can
be encapsulated or non-encapsulated.
The rated supply voltage does not exceed 1 100 1 000 V AC, and the rated supply frequency
and the internal operating frequencies do not exceed 500 Hz.
The core power does not exceed:
• 2 kVA for single-phase transformers;
• 10 kVA for polyphase transformers.
The rated output does not exceed:
• 40 kVA for single-phase transformers;
• 200 kVA for polyphase transformers.
This document is applicable to transformers without limitations of the core power and the
rated output both being subject to an agreement between the purchaser and the manufacturer.
Where applicable, the no-load output voltage or the rated output voltage does not exceed
1 000 V AC or 1 415 V ripple-free DC. For independent transformers, the no-load output
voltage and the rated output voltage exceeds is not less than 50 V AC or 120 V ripple-free
DC.
This document is not applicable to external circuits and their components intended to be
connected to the input terminals and output terminals of the transformers.
– 8 – IEC 61558-2-13:2022 RLV IEC 2022
NOTE 2 Transformers covered by this document are used only in applications where no insulation between
circuits is required by the installation rules or by the end product standard.
NOTE 3 Attention is drawn to the following, if necessary:
• for transformers intended to be used in vehicles, on board ships, and aircraft, additional
requirements (from other applicable standards, national rules, etc.) may be necessary;
• measures to protect the enclosure and the components inside the enclosure against
external influences such as fungus, vermin, termites, solar-radiation, and icing should also
be considered;
• the different conditions for transportation, storage, and operation of the transformers
should also be considered;
• additional requirements in accordance with other appropriate standards and national rules
may can be applicable to transformers intended for use in special environments.
NOTE 4 Future technological development of transformers may can necessitate a need to
increase the upper limit of the frequencies. Until then this document may can be used as a
guidance document.
This group safety publication focusing on safety guidance is primarily intended to be used as a
product safety standard for the products mentioned in the scope, but is also intended to be used
by technical committees in the preparation of publications for products similar to those
mentioned in the scope of this group safety publication, in accordance with the principles laid
down in IEC Guide 104 and lSO/lEC Guide 51.
One of the responsibilities of a technical committee is, wherever applicable, to make use of
basic safety publications and/or group safety publications in the preparation of its publications.
2 Normative references
This clause of IEC 61558-1:2017 is applicable except as follows:
Addition:
IEC 61558-1:20052017, Safety of power transformers, power supplies, reactors, power supply
units and similar products combinations thereof – Part 1: General requirements and tests
3 Terms and definitions
This clause of Part 1 is applicable except as follows:
Modification:
Delete the third paragraph.
Note 2 of 3.7.22 is not applicable.
Addition:
For the purposes of this document, the terms and definitions given in IEC 61558-1:2017 apply,
except as follows:
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
Replacement:
3.1.1015
auto-transformer
transformer in which input and output windings have a common part
Note 1 to entry: Auto-transformers may can have supplementary windings (see Figure 101) or tappings (see
Figure 102) for adjustment purposes.
Note 2 to entry: Transformers with windings separated at least by functional insulation and electrically connected,
will be treated as auto-transformers (see Figure 103).
Figure 101 – Windings Figure 102 – Tappings Figure 103 – Windings
separated by functional
isolation
Addition:
3.5.101
core power
power transformed by the core, if this core was used in a transformer with separate windings
at the same supply voltage, output voltage, frequency, power factor and thermal
characteristics
4 General requirements
This clause of IEC 61558-1:2017 is applicable.
5 General notes on tests
This clause of IEC 61558-1:2017 is applicable.
6 Ratings
This clause of IEC 61558-1:2017 is applicable except as follows:
Replacement Addition:
6.101 The rated output voltage shall not exceed 1 000 V AC or 1 415 V ripple-free DC. For
independent transformers the rated output voltage shall exceed 50 V AC or 120 V ripple-free
DC.
– 10 – IEC 61558-2-13:2022 RLV IEC 2022
6.102 The rated output shall not exceed:
• 40 kVA for single-phase transformers;
• 200 kVA for polyphase transformers.
Transformers without limitation of the rated output shall be subject to agreement between the
purchaser and the manufacturer.
6.103 The rated supply frequency and the internal operating frequencies shall not exceed
500 Hz.
6.104 The rated supply voltage shall not exceed 1 100 1 000 V AC.
6.105 The core power shall not exceed:
• 2 kVA for single-phase transformers;
• 10 kVA for polyphase transformers.
Transformers without limitation of the core power shall be subject to agreement between the
purchaser and the manufacturer.
The relation between the core power and the rated output is given determined by Formula (1):
VV−
max min
Core power VA ×rated output VA
[ ] [ ]
(1)
V
max
where
V and V are the highest and lowest values (rated supply voltage or rated output
max min
voltage).
V is the highest value of rated supply voltage or rated output voltage, expressed in V;
max
V is the lowest value of rated supply voltage or rated output voltage, expressed in V.
min
NOTE In this case, the limitation of the core power is applicable to the rated output.
Formula (1) is not applicable to a transformer with separate windings which are electrically
connected (see Figure 103). In this case, the core power of the transformer is equal to the
rated output.
Compliance with the requirements of 6.101 to 6.105 is checked by inspection of the marking.
7 Classification
This clause of IEC 61558-1:2017 is applicable.
8 Marking and other information
This clause of IEC 61558-1:2017 is applicable except as follows:
8.1 h)
Replacement:
=
The transformers shall be marked with one of the graphical symbols shown in 8.11;
Replacement of the content up to the first semi-colon by the following:
relevant graphical symbols shown in Table 101 that indicate the kind of transformer
8.11
Addition:
Symbol or graphical symbol Explanation or title Identification
Fail-safe auto-transformer
60417-5941
or
F
F
Non-short-circuit proof auto-transformer
60417-5942
or
Short-circuit proof auto-transformer (inherently or
60417-5943
non-inherently)
or
The symbol for linear power supply units shall be used in conjunction with the symbol
indicating the kind of transformer.
Table 101 – Symbols indicating the kind of transformer
Symbol or graphical symbol Explanation or title Identification
Fail-safe auto-transformer IEC 60417-5941:2002-10
Non-short-circuit proof auto-transformer IEC 60417-5942:2002-10
Short-circuit proof auto-transformer (inherently IEC 60417-5943:2002-10
or non-inherently)
Power supply unit, linear IEC 60417-6210:2013-10
– 12 – IEC 61558-2-13:2022 RLV IEC 2022
Addition:
8.101 If there is a terminal for connection to the star point, the maximum current to the star
point shall be marked.
9 Protection against electric shock
This clause of IEC 61558-1:2017 is applicable.
10 Change of input voltage setting
This clause of IEC 61558-1:2017 is applicable.
11 Output voltage and output current under load
This clause of IEC 61558-1:2017 is applicable.
12 No-load output voltage
This clause of IEC 61558-1:2017 is applicable except as follows:
Addition:
The no-load output voltage is measured when the transformer is connected to the rated
supply voltage at the rated supply frequency at ambient temperature.
12.101 The no-load output voltage shall not exceed 1 000 V AC or 1 415 V ripple-free DC
and for independent transformers shall exceed 50 V AC or 120 V ripple-free d.c. but not
exceed 1 000 V a.c. or 1 415 V ripple free DC.
For independent transformers, this output voltage limitation applies even when output
windings, not intended for interconnection, are connected in series.
NOTE 1 The requirement for series connection does not apply to associated or IP 00 transformers.
NOTE 2 An auto-transformer may can have more than one output winding for adjustment reasons.
12.102 The difference between the no-load output voltage and the output voltage under
load shall not be excessive.
The ratio between the no-load output voltage measured in Clause 12 and the output voltage
under load measured during the test of Clause 11, expressed as a percentage of the latter
voltage, shall not exceed the values shown in Table 102.
The difference is expressed as a percentage of the latter voltage calculated according to the
following formula: The ratio is determined by Formula (2):
UU−
no-load load
×100 %
( )
(2)
U
load
where
U is the no-load output voltage, expressed in V;
no-load
U is the output voltage under load no-load output voltage, expressed in V.
load
Table 101 102 – Output voltage difference ratio
Type of auto-transformer Difference Ratio between no-load output voltage
Rated output and output voltage under load
VA %
Inherently short-circuit-proof auto-transformers:
– up to and including 63 100
– over 63 up to and including 630 50
– over 630 20
Other auto-transformers:
– up to and including 10 100
– over 10 up to and including 25 50
– over 25 up to and including 63 20
– over 63 up to and including 250 15
– over 250 up to and including 630 10
– over 630 5
Compliance with the requirements of 12.101 and 12.102 is checked by measuring the no-load
output voltage at the ambient temperature when the transformer is connected to the rated
supply voltage at the rated supply frequency.
The difference ratio shall not exceed the values shown in Table 102.
13 Short-circuit voltage
This clause of IEC 61558-1:2017 is applicable.
14 Heating
This clause of IEC 61558-1:2017 is applicable.
15 Short-circuit and overload protection
This clause of IEC 61558-1:2017 is applicable.
16 Mechanical strength
This clause of IEC 61558-1:2017 is applicable.
17 Protection against harmful ingress of dust, solid objects and moisture
This clause of IEC 61558-1:2017 is applicable.
18 Insulation resistance, dielectric strength and leakage current
This clause of IEC 61558-1:2017 is applicable except as follows:
– 14 – IEC 61558-2-13:2022 RLV IEC 2022
Modification:
18.2 Table 7: In accordance with Table 13 of IEC 61558-1:2017 the values between input
circuits and output circuits, between each input circuit and all other input circuits, between
each output circuits and all other output circuits are not applicable.
18.3 Table 8a: lines 1) and 2) In accordance with Table 14 of IEC 61558-1:2017 the values
between input circuits and output circuits are not applicable.
19 Construction
This clause of Part 1 is applicable except as follows:
Addition:
19.106 Plug connected auto-transformers where the rated input voltage is higher than the
rated output voltage, shall not have any potential to earth at the output socket higher than the
rated output voltage.
This requirement shall be fulfilled by using one of the following methods.
19.106.1 Polarised input and output plug and socket-outlet system
In this case, an instruction shall be given for not using such a transformer with a non-polarised
plug and socket-outlet system.
19.106.2 Polarity detecting device (for non polarised input and output plug and socket-outlet
system)
A polarity detecting device shall only energise the output circuit when the potential to earth at
the poles of the output socket does not exceed the rated output voltage. The contact
separation of the breaking device shall be at least of 3 mm in each pole.
NOTE A magnetic relay is an example of polarity detecting device.
Compliance is checked by the following test.
The auto-transformer is connected to the mains at 1,06 times the rated input voltage under
the most unfavourable condition of load and output voltage. The test is repeated with the polarity
of the input reversed. During the test, the measured potential to earth of each pole shall not
exceed the maximum output voltage under load (1,06 times the rated output voltage taking
into account the permissible deviations of Clause 11).
Compliance is checked by measurement.
If the polarity detecting device uses a current flowing to the earth for the detection, this current
shall not exceed 0,75 mA and shall only be flowing for the period of measurement until the
polarity is reversed.
Compliance is checked by measurement.
All the tests are repeated under the fault conditions of H.2 of Annex H of Part 1. In this case
the potential to earth of each pole shall not exceed 1,06 times the maximum output voltage
under load for more than 5 s.
Compliance is checked by measurement.
19.111 Protection against direct contact with the live parts (contact path and drive) shall be
ensured.
Compliance is checked by inspection.
This clause of IEC 61558-1:2017 is applicable and general requirements for auto-transformers
are defined in 19.1.2 of IEC 61558-1:2017.
Addition:
19.101 Protection against direct contact with the live parts (contact path and drive) shall be
ensured.
Compliance is checked by inspection.
20 Components
This clause of IEC 61558-1:2017 is applicable.
21 Internal wiring
This clause of IEC 61558-1:2017 is applicable.
22 Supply connection and other external flexible cable or cords
This clause of IEC 61558-1:2017 is applicable.
23 Terminals for external conductors
This clause of IEC 61558-1:2017 is applicable.
24 Provisions for protective earthing
This clause of IEC 61558-1:2017 is applicable.
25 Screws and connections
This clause of IEC 61558-1:2017 is applicable.
26 Creepage distances, clearances and distances through insulation
This clause of IEC 61558-1:2017 is applicable except as follows:
Addition:
26.101 The values for creepage distances, clearances and distances through insulation for
working voltages above 1 000 V may be found by extrapolation.
– 16 – IEC 61558-2-13:2022 RLV IEC 2022
27 Resistance to heat, fire and tracking
This clause of IEC 61558-1:2017 is applicable.
28 Resistance to rusting
This clause of IEC 61558-1:2017 is applicable.
Annexes
The annexes of IEC 61558-1:2017 are applicable except as follows:.
Annex C
Creepage distances (cr), clearances (cl) and distances through
insulation (dti) Material group II (400 ≤CTI <600)
This annex of Part 1 is applicable, except as follows:
Addition:
The values for creepage distances, clearances and distances through insulation for working
voltages above 1 000 V may be found by extrapolation.
Annex D
Creepage distances (cr), clearances (cl) and distances through
insulation (dti) Material group I (CTI ≥600)
This annex of Part 1 is applicable, except as follows:
Addition:
The values for creepage distances, clearances and distances through insulation for working
voltages above 1 000V may be found by extrapolation.
Annex R
Explanations of the application of 4.2 of IEC 60664-1:2007
(see IEC 61558-1 Subclause 26.2)
Addition:
The values for working voltage above 1 000 V may be found by extrapolation.
– 18 – IEC 61558-2-13:2022 RLV IEC 2022
Bibliography
The bibliography of IEC 61558-1:2017 is applicable, except as follows:
Addition:
IEC 60204-1:2016, Safety of machinery – Electrical equipment of machines – Part 1: General
requirements
IEC 60364-4-41:2005, Low-voltage electrical installations – Part 4-41: Protection for safety -
Protection against electric shock
IEC 61140:2016, Protection against electric shock – Common aspects for installation and
equipment
IEC 61558 (all parts), Safety of transformers, reactors, power supply units and combinations
thereof
IEC 61558-2-16, Safety of transformers, reactors, power supply units and similar products for
supply voltages up to 1 100 V combinations thereof – Part 2-16: Particular requirements and
tests for switch mode power supply units and transformers for switch mode power supply units
for general applications
ISO/IEC Guide 51:2014, Safety aspects – Guidelines for their inclusion in standards
____________
___________
To be published.
IEC 61558-2-13 ®
Edition 3.0 2022-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
GROUP SAFETY PUBLICATION
PUBLICATION GROUPÉE DE SÉCURITÉ
Safety of transformers, reactors, power supply units and combinations thereof –
Part 2-13: Particular requirements and tests for auto-transformers and power
supply units incorporating auto-transformers for general applications
Sécurité des transformateurs, bobines d'inductance, blocs d'alimentation et
combinaisons de ces éléments –
Partie 2-13: Exigences particulières et essais pour les autotransformateurs et les
blocs d'alimentation qui incorporent des autotransformateurs pour applications
d'ordre général
– 2 – IEC 61558-2-13:2022 IEC 2022
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 7
3 Terms and definitions . 7
4 General requirements . 8
5 General notes on tests . 8
6 Ratings . 8
7 Classification . 9
8 Marking and other information . 9
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 . 12
18 Insulation resistance, dielectric strength and leakage current . 12
19 Construction . 12
20 Components . 12
21 Internal wiring . 12
22 Supply connection and other external flexible cable or cords . 12
23 Terminals for external conductors . 13
24 Provisions for protective earthing. 13
25 Screws and connections . 13
26 Creepage distances, clearances and distances through insulation . 13
27 Resistance to heat, fire and tracking . 13
28 Resistance to rusting . 13
Annexes . 14
Bibliography . 15
Figure 101 – Windings . 8
Figure 102 – Tappings . 8
Figure 103 – Windings separated by functional isolation . 8
Table 101 – Symbols indicating the kind of transformer . 10
Table 102 – Output voltage ratio . 11
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SAFETY OF TRANSFORMERS, REACTORS, POWER
SUPPLY UNITS AND COMBINATIONS THEREOF –
Part 2-13: Particular requirements and tests for
auto-transformers and power supply units incorporating
auto-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
...
IEC 61558-2-13 EXV ®
Edition 3.0 2022-10
EXTENDED VERSION
INTERNATIONAL
STANDARD
colour
inside
This extended version of IEC 61558-2-13:2022 includes the content of the references made to
IEC 61558-1:2017
GROUP SAFETY PUBLICATION
Safety of transformers, reactors, power supply units and combinations thereof –
Part 2-13: Particular requirements and tests for auto-transformers and power
supply units incorporating auto-transformers for general applications
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.
IEC Secretariat Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.
About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.
IEC publications search - webstore.iec.ch/advsearchform IEC Products & Services Portal - products.iec.ch
The advanced search enables to find IEC publications by a Discover our powerful search engine and read freely all the
variety of criteria (reference number, text, technical publications previews. With a subscription you will always have
committee, …). It also gives information on projects, replaced access to up to date content tailored to your needs.
and withdrawn publications.
Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished
The world's leading online dictionary on electrotechnology,
Stay up to date on all new IEC publications. Just Published
containing more than 22 300 terminological entries in English
details all new publications released. Available online and once
and French, with equivalent terms in 19 additional languages.
a month by email.
Also known as the International Electrotechnical Vocabulary
(IEV) online.
IEC Customer Service Centre - webstore.iec.ch/csc
If you wish to give us your feedback on this publication or need
further assistance, please contact the Customer Service
Centre: sales@iec.ch.
IEC 61558-2-13 EXV ®
Edition 3.0 2022-10
EXTENDED VERSION
INTERNATIONAL
STANDARD
colour
inside
This extended version of IEC 61558-2-13:2022 includes the content of the references made to
IEC 61558-1:2017
GROUP SAFETY PUBLICATION
Safety of transformers, reactors, power supply units and combinations thereof –
Part 2-13: Particular requirements and tests for auto-transformers and power
supply units incorporating auto-transformers for general applications
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.180 ISBN 978-2-8322-5933-7
– 2 – IEC 61558-2-13:2022 EXV © IEC 2022
CONTENTS
FOREWORD .9
INTRODUCTION TO IEC 61558-1:2017 . 12
INTRODUCTION . 15
1 Scope . 16
2 Normative references . 17
3 Terms and definitions . 20
4 General requirements . 34
5 General notes on tests . 35
6 Ratings . 37
7 Classification . 38
8 Marking and other information . 39
9 Protection against electric shock . 45
9.1 General . 45
9.2 Protection against contact with hazardous-live-parts . 46
9.2.1 Determination of hazardous-live-parts . 46
9.2.2 Accessibility to hazardous-live-parts . 46
9.2.3 Accessibility to non hazardous-live-part . 49
9.3 Protection against hazardous electrical discharge . 49
10 Change of input voltage setting . 49
11 Output voltage and output current under load . 50
12 No-load output voltage . 51
13 Short-circuit voltage . 52
14 Heating . 52
14.1 General requirements . 52
14.1.1 Temperature-rise test . 52
14.1.2 Alternative temperature-rise test . 54
14.1.3 Determination of steady-state conditions . 57
14.2 Application of 14.1 or 14.3 according to the insulation system . 58
14.3 Accelerated ageing test for undeclared class of insulation system . 59
14.3.1 General . 59
14.3.2 Heat run . 59
14.3.3 Vibration . 60
14.3.4 Moisture treatment . 60
14.3.5 Measurements . 60
15 Short-circuit and overload protection. 60
15.1 General requirements . 60
15.1.1 Short circuit and overload test method . 60
15.1.2 Alternative short circuit and overload test method . 62
15.2 Inherently short-circuit proof transformers . 62
15.3 Non-inherently short-circuit proof transformers . 62
15.4 Non-short-circuit proof transformers . 64
15.5 Fail-safe transformers . 64
16 Mechanical strength . 65
16.1 General . 65
16.2 Stationary transformers. 65
16.3 Portable transformers (except portable transformers with integral pins for
introduction in socket-outlet in the fixed wiring) . 65
16.4 Portable transformers provided with integral pins for introduction in socket-
outlets of the fixed wiring . 66
16.4.1 General requirements . 66
16.4.2 Portable transformers provided with integral pins according to EN
50075 (IEC plug type C) for introduction in socket-outlets of the fixed
wiring . 67
16.5 Additional requirements for transformers to be used in vehicles and railway
applications . 68
16.5.1 Transformers to be used in vehicles and railway applications . 68
16.5.2 Test requirements for the transportation of transformers . 69
17 Protection against harmful ingress of dust, solid objects and moisture . 69
17.1 Degrees of protection provided by enclosures (IP code) . 69
17.1.1 General requirements . 69
17.1.2 Tests on transformers with enclosure . 71
17.2 Humidity treatment . 73
18 Insulation resistance, dielectric strength and leakage current . 73
18.1 General . 73
18.2 Insulation resistance . 74
18.3 Dielectric strength test . 74
18.4 Insulation between and within windings . 76
18.5 Touch current and protective earthing conductor current . 76
18.5.1 General . 76
18.5.2 Touch current . 77
18.5.3 Protective earthing conductor current . 78
19 Construction . 78
19.1 General construction . 79
19.1.1 General . 79
19.1.2 Auto-transformers . 79
19.1.3 Separating transformers . 80
19.1.4 Isolating transformers and safety isolating transformers . 81
19.2 Flammability of materials . 83
19.3 Short-circuit characteristics of portable transformers . 83
19.4 Class II transformer contact prevention of accessible conductive parts . 83
19.5 Class II transformer insulation reassembling after service . 83
19.6 Loosening of wires, screws or similar parts . 84
19.7 Resistor or capacitor connection with accessible conductive parts . 84
19.8 Bridging of separated conductive parts by resistors or capacitors . 84
19.9 Insulating material separating input and output windings . 85
19.10 Accidental contact protection against hazardous-live-parts provided by
isolating coating . 85
19.11 Insulating material of handles, operating levers, knobs and similar parts . 86
19.12 Winding construction . 86
19.13 Fixing of handles, operating levers and similar parts . 90
– 4 – IEC 61558-2-13:2022 EXV © IEC 2022
19.14 Fixing of covers providing protection against electric shock . 90
19.15 Strain on fixed socket-outlets caused by pin-transformers connection. 91
19.16 Portable transformers for use in irregular or harsh conditions . 91
19.17 Drain hole of transformers protected against ingress of water . 91
19.18 Plug connected transformers protected against ingress of water . 91
19.19 Flexible cable or flexible cord connection for class I portable transformers . 91
19.20 SELV- and PELV-circuit separation of live parts. 91
19.21 Protection against contact for FELV-circuit . 92
19.22 Protective earthing regarding class II transformers . 92
19.23 Protective earthing regarding class III transformers . 92
20 Components . 93
21 Internal wiring . 98
22 Supply connection and other external flexible cables or cords . 98
23 Terminals for external conductors . 105
24 Provisions for protective earthing . 106
25 Screws and connections . 108
26 Creepage distances, clearances and distances through insulation . 110
26.1 General . 110
26.2 Creepage distances and clearances . 111
26.2.1 General . 111
26.2.2 Windings covered with adhesive tape . 111
26.2.3 Uncemented insulationing parts . 111
26.2.4 Cemented insulating parts . 111
26.2.5 Enclosed parts (e.g. by impregnation or potting) . 112
26.3 Distance through insulation . 113
27 Resistance to heat, fire and tracking . 124
27.1 General . 124
27.2 Resistance to heat . 124
27.2.1 General . 124
27.2.2 External accessible parts . 124
27.2.3 Internal parts . 125
27.3 Resistance to abnormal heat under fault conditions . 125
27.4 Resistance to fire. 126
27.4.1 General . 126
27.4.2 External accessible parts . 127
27.4.3 Internal parts . 127
27.5 Resistance to tracking . 128
28 Resistance to rusting. 128
Annex A (normative) Measurement of creepage distances and clearances . 129
Annex B (normative) Testing a series of transformers . 133
B.1 General . 133
B.2 Requirements . 133
B.3 Constructional inspection . 134
Annex C (void) . 135
Annex D (void) . 136
Annex E (normative) Glow-wire test . 137
E.1 General . 137
E.2 Severity . 137
E.3 Conditioning . 137
E.4 Test procedure . 137
Annex F (normative) Requirements for manually operated switches which are parts of
transformers assembly . 138
F.1 General . 138
F.2 Switches tested as a separate component . 138
F.3 Switches tested as part of the transformer . 138
Annex G (normative) Tracking test . 141
G.1 General . 141
G.2 Test specimen . 141
G.3 Test apparatus . 141
G.4 Procedure . 141
Annex H (normative) Electronic circuits . 142
H.1 General . 142
H.2 General notes on tests (addition to Clause 5) . 142
H.3 Short circuit and overload protection (addition to Clause 15) . 142
H.4 Creepage distances, clearances and distances through insulation (addition
to Clause 26) . 144
Annex I (informative) Dimensions for rectangular cross-section connectors of
transformers, basic dimensions and coordination . 146
Annex J (normative) Measuring network for touch-currents . 149
Annex K (normative) Insulated winding wires . 150
K.1 General . 150
K.2 Type tests . 150
K.2.1 General . 150
K.2.2 Dielectric strength test . 150
K.2.3 Flexibility and adherence . 150
K.2.4 Heat shock . 151
K.2.5 Retention of dielectric strength after bending . 151
K.3 Testing during manufacturing . 152
K.3.1 General . 152
K.3.2 Routine test . 152
K.3.3 Sampling test . 152
Annex L (normative) Routine tests (production tests) . 153
L.1 General . 153
L.2 Protective earthing continuity test. 153
L.3 Checking of no-load output voltage . 153
L.4 Dielectric strength test . 153
L.5 Checking of protective devices mounting . 154
L.6 Visual inspection . 154
L.7 Repetition test after routine dielectric strength test . 154
Annex M (informative) Examples to be used as a guide for 19.1 . 155
M.1 General . 155
– 6 – IEC 61558-2-13:2022 EXV © IEC 2022
M.2 Coil-former . 155
M.2.1 Concentric type . 155
M.2.2 Side-by-side type. 156
M.3 Windings . 156
M.3.1 Without screen . 156
M.3.2 With screen . 157
Annex N (informative) Examples for checking points of dielectric strength test voltages. 158
Annex O (void) . 160
Annex P (informative) Examples for measurement points of creepage distances and
clearances . 161
Annex Q (informative) Explanation of IP numbers for degrees of protection . 164
Q.1 General . 164
Q.2 Degrees of protection against access to hazardous parts and against solid
foreign objects . 164
Q.3 Degrees of protection against ingress of water . 166
Annex R (normative) Explanations of the application of 6.1.2.2.1 of IEC 60664-1:2007 . 167
R.1 Impulse dielectric test . 167
R.2 Example . 167
Annex S (void) . 169
Annex T (void) . 170
Annex U (void) . 171
Annex V (informative) Symbols to be used for thermal cut-outs . 172
V.1 General . 172
V.2 Non-self-resetting thermal cut-out (see 3.3.4) . 172
V.3 Self-resetting thermal cut-out (see 3.3.3) . 172
Annex W (normative) Coated printed circuit boards . 173
W.1 Preamble. 173
W.2 General . 173
W.3 Cold . 173
W.4 Rapid change of temperature . 173
W.5 Additional tests . 173
Bibliography . 174
Index of defined terms . 176
Figure 1 – IEC 61558 principle . 13
Figure 101 – Windings. 21
Figure 102 – Tappings. 21
Figure 103 – Windings separated by functional isolation . 21
Figure 2 – Mounting box for flush-type transformer . 36
Figure 3 – Test pin (see IEC 61032, test probe 13). 47
Figure 4 – Standard test finger (see IEC 61032, test probe B) . 48
Figure 5 – Example of back-to-back method – Single phase . 56
Figure 6 – Example of back-to-back method – Three phase . 56
Figure 7 – Amplitude spectrum density for random testing . 68
Figure 8 – Normalised spectrum of shock . 69
Figure 9 – Test voltage sequence . 76
Figure 10 – Test configuration: single-phase equipment on star TN or TT system . 78
Figure 11 – Abrasion resistance test for insulating coated layers . 86
Figure 12 – Flexing test apparatus . 102
Figure 13 – Test arrangement for checking mechanical withstanding of insulating
materials in thin sheet layers . 116
Figure 14 – Ball-pressure apparatus . 124
Figure A.1 – Example 1 . 129
Figure A.2 – Example 2 . 130
Figure A.3 – Example 3 . 130
Figure A.4 – Example 4 . 130
Figure A.5 – Example 5 . 131
Figure A.6 – Example 6 . 131
Figure A.7 – Example 7 . 132
Figure A.8 – Example 8 . 132
Figure H.1 – Example of an electronic circuit with low-power points . 145
Figure J.1 – Measuring network for touch-current . 149
Figure M.1 – Examples for concentric type constructions . 155
Figure M.2 – Examples for side-by-side type constructions . 156
Figure M.3 – Examples for winding constructions without screen . 156
Figure M.4 – Examples for wrapped winding constructions . 157
Figure M.5 – Examples for winding constructions with screen . 157
Figure N.1 – Transformer of class I construction with metal enclosure . 158
Figure N.2 – Transformer of class II construction with metal enclosure . 159
Figure N.3 – Transformer of class II construction with enclosure of insulating material . 159
Figure P.1 – Transformer of class I construction . 161
Figure P.2 – Transformer of class I construction with earthed metal screen . 162
Figure P.3 – Transformer of class II construction with metal enclosure . 162
Figure P.4 – Transformer of class II construction with enclosure of insulating material . 163
Figure V.1 – Restored by manual operation. 172
Figure V.2 – Restored by disconnection of the supply . 172
Figure V.3 – Thermal link (see 3.3.5) . 172
Figure V.4 – Self-resetting thermal cut-out . 172
Table 1 – Symbols used on equipment or in instructions . 42
Table 101 – Symbols indicating the kind of transformer . 44
Table 102 – Output voltage ratio . 51
Table 2 – Values of maximum temperatures in normal use . 57
Table 3 – Explanation of the maximum winding temperatures required in Table 2 . 58
Table 4 – Test temperature and testing time (in days) per cycle . 59
Table 5 – Maximum values of temperatures under short-circuit or overload conditions . 61
Table 6 – Values of T and k for fuses . 63
– 8 – IEC 61558-2-13:2022 EXV © IEC 2022
Table 7 – Pull force on pins . 67
Table 8 – Conditions for vibration testing (random) . 68
Table 9 – Amplitude spectrum density ASD values for accelerated life testing . 68
Table 10 – Frequency values depending on the weight of the specimen . 68
Table 11 – Excitation values for vibration testing . 69
Table 12 – Solid-object-proof transformer test . 71
Table 13 – Values of insulation resistance . 74
Table 14 – Table of dielectric strength test voltages . 75
Table 15 – Limits for currents . 78
Table 16 – Nominal cross-sectional areas of external flexible cables or cords . 100
Table 17 – Pull and torque to be applied to external flexible cables or cords fixed to
stationary and portable transformers . 104
Table 18 – Torque to be applied to screws and connections . 109
Table 19 – Torque test on glands. 110
Table 20 – Clearances in mm . 117
Table 21 – Creepage distances in mm . 118
Table 22 – Distance through insulation in mm . 119
Table 23 – Creepage distances and clearance between terminals for external connection . 120
Table 24 – Values of FIW wires with minimum overall disameter and minimum test
voltages according to the total enamel increase . 122
Table A.1 – Width of groove values depending on the pollution degree . 129
Table F.1 – Peak surge current of additional loads . 139
Table I.1 – Dimensions of rectangular copper connectors . 147
Table K.1 – Mandrel diameter . 151
Table K.2 – Oven temperature . 151
Table Q.1 – Degrees of protection against access to hazardous parts indicated by the
first characteristic numeral . 165
Table Q.2 – Degrees of protection against solid foreign objects indicated by the first
characteristic numeral . 165
Table Q.3 – Degrees of protection indicated by the second characteristic numeral . 166
Table R.1 – Impulse test voltage according to 6.1.2.2.1 of IEC 60664-1:2007 . 167
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SAFETY OF TRANSFORMERS, REACTORS, POWER
SUPPLY UNITS AND COMBINATIONS THEREOF –
Part 2-13: Particular requirements and tests for
auto-transformers and power supply units incorporating
auto-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.
This extended version (EXV) of the official IEC Standard provides the user with a
comprehensive content of the Standard.
Particular subclauses of IEC 61558-1:2017 are displayed in the content on a blue
background.
– 10 – IEC 61558-2-13:2022 EXV © IEC 2022
International standard IEC 61558-2-13 has been prepared by IEC technical committee 96:
Transformers, reactors, power supply units and combinations thereof.
This third edition cancels and replaces the second edition published in 2009. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
adjustment of structure and references in accordance with IEC 61558-1:2017;
description of constructions moved to IEC 61558-1:2017;
new symbol for power supply unit with linearly regulated output voltage.
The text of this document is based on the following documents:
Draft Report on voting
96/549/FDIS 96/555/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/standardsdev/publications.
It has the status of a group safety publication in accordance with IEC Guide 104.
This document is to be used in conjunction with 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 auto-
transformers and power supply units incorporating auto-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 a particular subclause of IEC 61558-1:2017 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 IEC 61558-1:2017 is to be adapted accordingly.
In this document, the following pr
...
IEC 61558-2-13 ®
Edition 3.0 2022-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
GROUP SAFETY PUBLICATION
PUBLICATION GROUPÉE DE SÉCURITÉ
Safety of transformers, reactors, power supply units and combinations thereof –
Part 2-13: Particular requirements and tests for auto-transformers and power
supply units incorporating auto-transformers for general applications
Sécurité des transformateurs, bobines d'inductance, blocs d'alimentation et
combinaisons de ces éléments –
Partie 2-13: Exigences particulières et essais pour les autotransformateurs et les
blocs d'alimentation qui incorporent des autotransformateurs pour applications
d'ordre général
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.
Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite ni
utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie et
les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez
les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.
IEC Secretariat Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.
About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.
IEC publications search - webstore.iec.ch/advsearchform IEC Products & Services Portal - products.iec.ch
The advanced search enables to find IEC publications by a Discover our powerful search engine and read freely all the
variety of criteria (reference number, text, technical publications previews. With a subscription you will always have
committee, …). It also gives information on projects, replaced access to up to date content tailored to your needs.
and withdrawn publications.
Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished
The world's leading online dictionary on electrotechnology,
Stay up to date on all new IEC publications. Just Published
containing more than 22 300 terminological entries in English
details all new publications released. Available online and once
and French, with equivalent terms in 19 additional languages.
a month by email.
Also known as the International Electrotechnical Vocabulary
(IEV) online.
IEC Customer Service Centre - webstore.iec.ch/csc
If you wish to give us your feedback on this publication or need
further assistance, please contact the Customer Service
Centre: sales@iec.ch.
A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.
A propos des publications IEC
Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la
plus récente, un corrigendum ou amendement peut avoir été publié.
Recherche de publications IEC - Découvrez notre puissant moteur de recherche et consultez
webstore.iec.ch/advsearchform gratuitement tous les aperçus des publications. Avec un
La recherche avancée permet de trouver des publications IEC abonnement, vous aurez toujours accès à un contenu à jour
en utilisant différents critères (numéro de référence, texte, adapté à vos besoins.
comité d’études, …). Elle donne aussi des informations sur les
projets et les publications remplacées ou retirées. Electropedia - www.electropedia.org
Le premier dictionnaire d'électrotechnologie en ligne au monde,
IEC Just Published - webstore.iec.ch/justpublished
avec plus de 22 300 articles terminologiques en anglais et en
Restez informé sur les nouvelles publications IEC. Just
français, ainsi que les termes équivalents dans 19 langues
Published détaille les nouvelles publications parues.
additionnelles. Egalement appelé Vocabulaire
Disponible en ligne et une fois par mois par email.
Electrotechnique International (IEV) en ligne.
Service Clients - webstore.iec.ch/csc
Si vous désirez nous donner des commentaires sur cette
publication ou si vous avez des questions contactez-nous:
sales@iec.ch.
IEC Products & Services Portal - products.iec.ch
IEC 61558-2-13 ®
Edition 3.0 2022-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
GROUP SAFETY PUBLICATION
PUBLICATION GROUPÉE DE SÉCURITÉ
Safety of transformers, reactors, power supply units and combinations thereof –
Part 2-13: Particular requirements and tests for auto-transformers and power
supply units incorporating auto-transformers for general applications
Sécurité des transformateurs, bobines d'inductance, blocs d'alimentation et
combinaisons de ces éléments –
Partie 2-13: Exigences particulières et essais pour les autotransformateurs et les
blocs d'alimentation qui incorporent des autotransformateurs pour applications
d'ordre général
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.180 ISBN 978-2-8322-5779-1
– 2 – IEC 61558-2-13:2022 IEC 2022
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 7
3 Terms and definitions . 7
4 General requirements . 8
5 General notes on tests . 8
6 Ratings . 8
7 Classification . 9
8 Marking and other information . 9
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 . 12
18 Insulation resistance, dielectric strength and leakage current . 12
19 Construction . 12
20 Components . 12
21 Internal wiring . 12
22 Supply connection and other external flexible cable or cords . 12
23 Terminals for external conductors . 13
24 Provisions for protective earthing. 13
25 Screws and connections . 13
26 Creepage distances, clearances and distances through insulation . 13
27 Resistance to heat, fire and tracking . 13
28 Resistance to rusting . 13
Annexes . 14
Bibliography . 15
Figure 101 – Windings . 8
Figure 102 – Tappings . 8
Figure 103 – Windings separated by functional isolation . 8
Table 101 – Symbols indicating the kind of transformer . 10
Table 102 – Output voltage ratio . 11
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SAFETY OF TRANSFORMERS, REACTORS, POWER
SUPPLY UNITS AND COMBINATIONS THEREOF –
Part 2-13: Particular requirements and tests for
auto-transformers and power supply units incorporating
auto-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.
International standard IEC 61558-2-13 has been prepared by IEC technical committee 96:
Transformers, reactors, power supply units and combinations thereof.
This third edition cancels and replaces the second edition published in 2009. 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 symbol for power supply unit with linearly regulated output voltage.
– 4 – IEC 61558-2-13:2022 IEC 2022
The text of this document is based on the following documents:
Draft Report on voting
96/549/FDIS 96/555/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/standardsdev/publications.
It has the status of a group safety publication in accordance with IEC Guide 104.
This document is to be used in conjunction with 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 auto-
transformers and power supply units incorporating auto-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 a particular subclause of IEC 61558-1:2017 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 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 "http://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.
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 the limitation of voltage and horizontal safety function
for SELV, in accordance with IEC 60364-4-41.
The group safety function (GSF) is used because of responsibility for example 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 used 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 61558-2-13:2022 IEC 2022
SAFETY OF TRANSFORMERS, REACTORS, POWER
SUPPLY UNITS AND COMBINATIONS THEREOF –
Part 2-13: Particular requirements and tests for
auto-transformers and power supply units incorporating
auto-transformers for general applications
1 Scope
Replacement:
This part of IEC 61558 deals with the safety of auto-transformers for general applications and
power supply units incorporating auto-transformers for general applications. Transformers
incorporating electronic circuits are also covered by this document.
NOTE 1 Safety includes electrical, thermal and mechanical aspects.
Unless otherwise specified, from here onward, the term transformer covers auto-transformers
for general applications and power supply units incorporating auto-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.
This document is applicable to stationary or portable, single-phase or polyphase, air-cooled
(natural or forced) independent or associated dry-type 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 operating frequencies do not exceed 500 Hz.
The core power does not exceed:
• 2 kVA for single-phase transformers;
• 10 kVA for polyphase transformers.
The rated output does not exceed:
• 40 kVA for single-phase transformers;
• 200 kVA for polyphase transformers.
This document is applicable to transformers without limitations of the core power and the
rated output both being subject to an agreement between the purchaser and the manufacturer.
Where applicable, the no-load output voltage or the rated output voltage does not exceed
1 000 V AC or 1 415 V ripple-free DC. For independent transformers, the no-load output
voltage and the rated output voltage is not less than 50 V AC or 120 V ripple-free DC.
This document is not applicable to external circuits and their components intended to be
connected to the input terminals and output terminals of the transformers.
NOTE 2 Transformers covered by this document are used only in applications where no insulation between
circuits is required by the installation rules or by the end product standard.
Attention is drawn to the following, if necessary:
• for transformers intended to be used in vehicles, on board ships, and aircraft, additional
requirements (from other applicable standards, national rules, etc.);
• measures to protect the enclosure and the components inside the enclosure against
external influences such as fungus, vermin, termites, solar-radiation, and icing;
• the different conditions for transportation, storage, and operation of the transformers;
• additional requirements in accordance with other appropriate standards and national rules
can be applicable to transformers intended for use in special environments.
Future technological development of transformers can necessitate a need to increase the
upper limit of the frequencies. Until then this document can be used as a guidance document.
This group safety publication focusing on safety guidance is primarily intended to be used as a
product safety standard for the products mentioned in the scope, but is also intended to be used
by technical committees in the preparation of publications for products similar to those
mentioned in the scope of this group safety publication, in accordance with the principles laid
down in IEC Guide 104 and lSO/lEC Guide 51.
One of the responsibilities of a technical committee is, wherever applicable, to make use of
basic safety publications and/or group safety publications in the preparation of its publications.
2 Normative references
This clause of IEC 61558-1:2017 is applicable except as follows:
Addition:
IEC 61558-1:2017, Safety of transformers, reactors, power supply units and combinations
thereof – Part 1: General requirements and tests
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 61558-1:2017 apply,
except as follows:
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
Replacement:
3.1.5
auto-transformer
transformer in which input and output windings have a common part
Note 1 to entry: Auto-transformers can have supplementary windings (see Figure 101) or tappings (see
Figure 102) for adjustment purposes.
Note 2 to entry: Transformers with windings separated at least by functional insulation and electrically connected,
will be treated as auto-transformers (see Figure 103).
– 8 – IEC 61558-2-13:2022 IEC 2022
Figure 101 – Windings Figure 102 – Tappings Figure 103 – Windings
separated by functional
isolation
Addition:
3.5.101
core power
power transformed by the core, if this core was used in a transformer with separate windings
at the same supply voltage, output voltage, frequency, power factor and thermal
characteristics
4 General requirements
This clause of IEC 61558-1:2017 is applicable.
5 General notes on tests
This clause of IEC 61558-1:2017 is applicable.
6 Ratings
This clause of IEC 61558-1:2017 is applicable except as follows:
Addition:
6.101 The rated output voltage shall not exceed 1 000 V AC or 1 415 V ripple-free DC. For
independent transformers the rated output voltage shall exceed 50 V AC or 120 V ripple-free
DC.
6.102 The rated output shall not exceed:
• 40 kVA for single-phase transformers;
• 200 kVA for polyphase transformers.
Transformers without limitation of the rated output shall be subject to agreement between the
purchaser and the manufacturer.
6.103 The rated supply frequency and the internal operating frequencies shall not exceed
500 Hz.
6.104 The rated supply voltage shall not exceed 1 000 V AC.
6.105 The core power shall not exceed:
• 2 kVA for single-phase transformers;
• 10 kVA for polyphase transformers.
Transformers without limitation of the core power shall be subject to agreement between the
purchaser and the manufacturer.
The relation between the core power and the rated output is determined by Formula (1):
VV−
max min
Core power VA ×rated output VA
[ ] [ ]
(1)
V
max
where
V is the highest value of rated supply voltage or rated output voltage, expressed in V;
max
V is the lowest value of rated supply voltage or rated output voltage, expressed in V.
min
NOTE In this case, the limitation of the core power is applicable to the rated output.
Formula (1) is not applicable to a transformer with separate windings which are electrically
connected (see Figure 103). In this case, the core power of the transformer is equal to the
rated output.
Compliance with the requirements of 6.101 to 6.105 is checked by inspection of the marking.
7 Classification
This clause of IEC 61558-1:2017 is applicable.
8 Marking and other information
This clause of IEC 61558-1:2017 is applicable except as follows:
8.1 h)
Replacement of the content up to the first semi-colon by the following:
relevant graphical symbols shown in Table 101 that indicate the kind of transformer
8.11
Addition:
The symbol for linear power supply units shall be used in conjunction with the symbol
indicating the kind of transformer.
=
– 10 – IEC 61558-2-13:2022 IEC 2022
Table 101 – Symbols indicating the kind of transformer
Symbol or graphical symbol Explanation or title Identification
Fail-safe auto-transformer IEC 60417-5941:2002-10
Non-short-circuit proof auto-transformer IEC 60417-5942:2002-10
Short-circuit proof auto-transformer (inherently IEC 60417-5943:2002-10
or non-inherently)
Power supply unit, linear IEC 60417-6210:2013-10
Addition:
8.101 If there is a terminal for connection to the star point, the maximum current to the star
point shall be marked.
9 Protection against electric shock
This clause of IEC 61558-1:2017 is applicable.
10 Change of input voltage setting
This clause of IEC 61558-1:2017 is applicable.
11 Output voltage and output current under load
This clause of IEC 61558-1:2017 is applicable.
12 No-load output voltage
This clause of IEC 61558-1:2017 is applicable except as follows:
Addition:
12.101 The no-load output voltage shall not exceed 1 000 V AC or 1 415 V ripple-free DC
and for independent transformers shall exceed 50 V AC or 120 V ripple free DC.
For independent transformers, this output voltage limitation applies even when output
windings, not intended for interconnection, are connected in series.
NOTE 1 The requirement for series connection does not apply to associated or IP 00 transformers.
NOTE 2 An auto-transformer can have more than one output winding for adjustment reasons.
12.102 The difference between the no-load output voltage and the output voltage under
load shall not be excessive.
The ratio between the no-load output voltage measured in Clause 12 and the output voltage
under load measured during the test of Clause 11, expressed as a percentage of the latter
voltage, shall not exceed the values shown in Table 102.
The ratio is determined by Formula (2):
UU−
no-load load
×100 %
( ) (2)
U
load
where
U is the no-load output voltage, expressed in V;
no-load
U is the no-load output voltage, expressed in V.
load
Table 102 – Output voltage ratio
Type of transformer Ratio between no-load output voltage
Rated output and output voltage under load
VA %
Inherently short-circuit-proof transformers:
– up to and including 63 100
– over 63 up to and including 630 50
– over 630 20
Other transformers:
– up to and including 10 100
– over 10 up to and including 25 50
– over 25 up to and including 63 20
– over 63 up to and including 250 15
– over 250 up to and including 630 10
– over 630 5
Compliance with the requirements of 12.101 and 12.102 is checked by measuring the no-load
output voltage at the ambient temperature when the transformer is connected to the rated
supply voltage at the rated supply frequency.
The ratio shall not exceed the values shown in Table 102.
13 Short-circuit voltage
This clause of IEC 61558-1:2017 is applicable.
14 Heating
This clause of IEC 61558-1:2017 is applicable.
– 12 – IEC 61558-2-13:2022 IEC 2022
15 Short-circuit and overload protection
This clause of IEC 61558-1:2017 is applicable.
16 Mechanical strength
This clause of IEC 61558-1:2017 is applicable.
17 Protection against harmful ingress of dust, solid objects and moisture
This clause of IEC 61558-1:2017 is applicable.
18 Insulation resistance, dielectric strength and leakage current
This clause of IEC 61558-1:2017 is applicable except as follows:
Modification:
18.2 In accordance with Table 13 of IEC 61558-1:2017 the values between input circuits
and output circuits, between each input circuit and all other input circuits, between each
output circuits and all other output circuits are not applicable.
18.3 In accordance with Table 14 of IEC 61558-1:2017 the values between input circuits
and output circuits are not applicable.
19 Construction
This clause of IEC 61558-1:2017 is applicable and general requirements for auto-transformers
are defined in 19.1.2 of IEC 61558-1:2017.
Addition:
19.101 Protection against direct contact with the live parts (contact path and drive) shall be
ensured.
Compliance is checked by inspection.
20 Components
This clause of IEC 61558-1:2017 is applicable.
21 Internal wiring
This clause of IEC 61558-1:2017 is applicable.
22 Supply connection and other external flexible cable or cords
This clause of IEC 61558-1:2017 is applicable.
23 Terminals for external conductors
This clause of IEC 61558-1:2017 is applicable.
24 Provisions for protective earthing
This clause of IEC 61558-1:2017 is applicable.
25 Screws and connections
This clause of IEC 61558-1:2017 is applicable
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.
Loading comments...