SIST EN 61558-2-20:2011
Safety of transformers, reactors, power supply units and combinations thereof - Part 2-20: Particular requirements and tests for small reactors (IEC 61558-2-20:2010)
- Abstract
IEC 61558-2-20:2010 deals with the safety of small reactors for general applications. This part is applicable to stationary or portable, single-phase or polyphase, air-cooled (natural or forced) general purpose reactors including alternating current, premagnetised and current compensated independent or associated reactors. This second edition cancels and replaces the first edition published in 2000. It constitutes a technical revision. The main changes consist of updating this part in accordance with IEC 61558-1:2005. This part has the status of a group safety publication in accordance with IEC Guide 104. The attention of National Committees is drawn to the fact that equipment manufacturers and testing organizations may need a transitional period following publication of a new, amended or revised IEC publication in which to make products in accordance with the new requirements and to equip themselves for conducting new or revised tests. It is the recommendation of the committee that the content of this publication be adopted for implementation nationally not earlier than 12 months from the date of publication. In the meantime, the previous edition can still be ordered by contacting your local IEC member National Committee or the IEC Central Office.
- Status
- Published
- Publication Date
- 08-Mar-2011
- Technical Committee
- I96 - Imaginarni 96
- Current Stage
- 6060 - National Implementation/Publication (Adopted Project)
- Start Date
- 02-Mar-2011
- Due Date
- 07-May-2011
- Completion Date
- 09-Mar-2011
- Directive
- 2006/95/EC - Directive 2006/95/EC of the European Parliament and of the Council of 12 December 2006 on the harmonisation of the laws of Member States relating to electrical equipment designed for use within certain voltage limits (codified version)OJ Ref: C 348/03 OJ Date: 28-Nov-2013 Conflicting Date: 02-Jan-2014
2014/35/EU - Directive 2014/35/EU of the European Parliament and of the Council of 26 February 2014 on the harmonisation of the laws of the Member States relating to the making available on the market of electrical equipment designed for use within certain voltage limitsOJ Ref: C 249/03 OJ Date: 08-Jul-2016
SIST EN 61558-2-20:2011 is the Slovenian adoption of EN 61558-2-20:2011, published by SIST and based on IEC 61558-2-20:2010. It specifies safety requirements and tests for small reactors used in general applications, so manufacturers, test labs, quality teams and buyers can check whether a reactor design, marking and construction meet the expected safety conditions.
What does SIST EN 61558-2-20:2011 specify?
SIST EN 61558-2-20:2011 gives the particular safety requirements and test methods for small reactors. It is written as a companion to EN 61558-1, which provides the general requirements and tests.
The scope covers stationary or portable reactors, single-phase or polyphase reactors, and air-cooled reactors with natural or forced cooling. It includes alternating current (AC), premagnetised and current compensated reactors, whether they are independent or associated, and whether the windings are encapsulated or non-encapsulated.
A practical limit is that the document is aimed at general-purpose dry-type reactors within its stated electrical ratings. It also notes that reactors filled with liquid dielectric or pulverised material are treated separately.
| Annex | What it covers |
|---|---|
| Annex ZA | Normative references to international publications and their corresponding European publications |
| Annexes A-V of Part 1 | Applicable general annexes from EN 61558-1 |
The document excludes reactors covered by IEC 60289 and the lamp controlgear standards IEC 61347-2-8 and IEC 61347-2-9.
What are the key requirements of SIST EN 61558-2-20:2011?
SIST EN 61558-2-20:2011 mainly sets limits, markings and tests that show a reactor is safe in normal use and under overload conditions. The most important points are the rating limits, the classification of reactor types, the marking requirements and the type-specific tests.
Ratings and application limits
The rated supply voltage is limited, and the standard also restricts the supply and internal operating frequencies. It gives separate power limits for single-phase and polyphase reactors, with an exception where the purchaser and manufacturer agree otherwise. In practice, this tells a buyer what kind of reactor falls inside the standard before any testing starts.
The standard also requires rated inductance and rated resistance to be given at the rated ambient temperature under no-load conditions, with tolerances declared by the manufacturer. That matters because users need stable data for design, selection and verification.
Classification of protection
Clause 7 classifies reactors by protection against electric shock as class I, class II or class III. It also classifies them by behavior under abnormal use as inherently overload proof, non-inherently overload proof, non-overload proof or fail-safe reactors.
This classification matters because it drives both the construction and the test route. A lab or quality engineer needs to know which protection concept the product claims before choosing the right checks.
Marking and user information
Clause 8 requires clear marking of the electrical ratings and identification data, including supply voltage, frequency, voltage drop or rated power, current, inductance or resistance, current type marking, model reference and manufacturer identification. It also covers ambient temperature, duty cycle, switching frequency for inverter supply, forced-air cooling identification and class symbols.
This matters in practice because the marking is the fast way to confirm the reactor has been specified for the intended installation. The standard also requires clear marking for overload-proof and fail-safe reactors, including information needed for correct replacement of protective devices.
Voltage setting and voltage drop
Clause 10 requires reactors with more than one rated supply voltage or more than one rated voltage drop to be arranged so the setting cannot be changed without a tool. The set value must also be visible when the reactor is ready for use.
Clause 11 limits the permitted deviation of voltage drop under load. For premagnetised reactors and reactors with added components such as capacitors or rectifiers, the allowed deviation is wider. In practice, this means the reactor has to perform close to its declared output behavior when it is loaded.
Heating and overload behavior
Clause 14 checks heating with the reactor supplied at rated frequency and at 1.1 times rated supply current. For tapped windings, the evaluation uses the hottest result. That helps confirm the thermal design at the worst operating point.
Clause 15 then checks how the reactor behaves under overload or abnormal use, depending on its classification. Fail-safe reactors get a specific destructive-type test sequence that is intended to show that failure happens safely and without danger to the user or surroundings.
Construction and components
Clause 19 adds a stress test to show that higher currents do not cause displacement or deformation of the core, windings or connections. After the test, the reactor is inspected for looseness, reduced creepage distances or clearances, and loss of protection.
Clause 20 treats an indirect-heating PTC resistor (positive temperature coefficient resistor) as a non-self-resetting thermal cut-out. It also subjects the reactor to a long-duration operating test at elevated voltage and load so the protective action and end condition can be checked.
What terms does SIST EN 61558-2-20:2011 define?
A reactor is an arrangement of one or more windings whose impedance depends on frequency and works by self-induction through a magnetic core or air.
An alternating current reactor (AC reactor) is a reactor in which the magnetising current creates an alternating magnetic field that changes polarity with frequency.
A premagnetised reactor is a reactor with a direct-current magnetising component and a superimposed alternating-current component that changes the magnetic field.
A current compensated reactor is a reactor with at least two windings on a common core, arranged so their magnetising currents oppose each other and reduce magnetic flux.
An overload proof reactor is a reactor that stays within temperature limits during overload and still meets the standard after the overload is removed.
A fail-safe reactor is a reactor that, after abnormal use, stops functioning by an interruption in the failing circuit but does not create danger for the user or surroundings.
A PTC resistor is a positive temperature coefficient resistor, and here the standard treats the indirect-heating type as a non-self-resetting thermal cut-out.
Who uses SIST EN 61558-2-20:2011?
SIST EN 61558-2-20:2011 is used by reactor manufacturers, design engineers, test laboratories, certification bodies and quality managers. They use it to choose the correct reactor type, set ratings, define markings, run safety tests and document conformity.
It is also relevant to purchasers and integrators who specify small reactors in power equipment, control equipment and other installations where inductive components are part of the function. In those cases, the standard helps them confirm the reactor is suitable for the intended operating conditions, cooling method and overload concept.
What changed in SIST EN 61558-2-20:2011 from the previous edition?
SIST EN 61558-2-20:2011 supersedes EN 61558-2-20:2000, and the Slovenian listing identifies it as replacing SIST EN 61558-2-20:2001. The main change stated in the document is that the part was updated in line with IEC/EN 61558-1:2005.
Which standards are used with SIST EN 61558-2-20:2011?
SIST EN 61558-2-20:2011 is intended to be used together with IEC 61558-1:2005, or EN 61558-1:2005 with corrigendum August 2006 in the European adoption. Part 1 supplies the general requirements, while this part adds or modifies the reactor-specific ones.
Clause 26 also points to IEC 61558-2-16 for creepage-distance values above 30 kHz. The scope names IEC 60289, IEC 61347-2-8 and IEC 61347-2-9 as standards covering products outside this part.
What does the SIST EN 61558-2-20:2011 document contain?
The document follows the Part 1 structure and covers clauses 1 to 28, from scope and definitions through ratings, marking, protection, construction, wiring, terminals, earthing, screws, insulation distances and resistance to heat, fire, tracking and rusting. It also includes Annex ZA for normative references and uses the Annexes A-V of Part 1.
Clause 8 includes the marking symbol table, and Clause 15 gives separate overload test routes for each reactor classification. The document also includes test procedures for voltage setting, voltage drop, heating, abnormal use, construction strength and component behavior, so it can be used for design verification, type testing and conformity assessment.
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- 01-Jan-2014
- Effective Date
- 21-Sep-2021
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- 03-Feb-2026
- Effective Date
- 07-Jan-2014
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Frequently Asked Questions
SIST EN 61558-2-20:2011 is a standard published by the Slovenian Institute for Standardization (SIST). Its full title is "Safety of transformers, reactors, power supply units and combinations thereof - Part 2-20: Particular requirements and tests for small reactors (IEC 61558-2-20:2010)". This standard covers: IEC 61558-2-20:2010 deals with the safety of small reactors for general applications. This part is applicable to stationary or portable, single-phase or polyphase, air-cooled (natural or forced) general purpose reactors including alternating current, premagnetised and current compensated independent or associated reactors. This second edition cancels and replaces the first edition published in 2000. It constitutes a technical revision. The main changes consist of updating this part in accordance with IEC 61558-1:2005. This part has the status of a group safety publication in accordance with IEC Guide 104. The attention of National Committees is drawn to the fact that equipment manufacturers and testing organizations may need a transitional period following publication of a new, amended or revised IEC publication in which to make products in accordance with the new requirements and to equip themselves for conducting new or revised tests. It is the recommendation of the committee that the content of this publication be adopted for implementation nationally not earlier than 12 months from the date of publication. In the meantime, the previous edition can still be ordered by contacting your local IEC member National Committee or the IEC Central Office.
IEC 61558-2-20:2010 deals with the safety of small reactors for general applications. This part is applicable to stationary or portable, single-phase or polyphase, air-cooled (natural or forced) general purpose reactors including alternating current, premagnetised and current compensated independent or associated reactors. This second edition cancels and replaces the first edition published in 2000. It constitutes a technical revision. The main changes consist of updating this part in accordance with IEC 61558-1:2005. This part has the status of a group safety publication in accordance with IEC Guide 104. The attention of National Committees is drawn to the fact that equipment manufacturers and testing organizations may need a transitional period following publication of a new, amended or revised IEC publication in which to make products in accordance with the new requirements and to equip themselves for conducting new or revised tests. It is the recommendation of the committee that the content of this publication be adopted for implementation nationally not earlier than 12 months from the date of publication. In the meantime, the previous edition can still be ordered by contacting your local IEC member National Committee or the IEC Central Office.
SIST EN 61558-2-20:2011 is classified under the following ICS (International Classification for Standards) categories: 29.180 - Transformers. Reactors. The ICS classification helps identify the subject area and facilitates finding related standards.
SIST EN 61558-2-20:2011 has the following relationships with other standards: It is inter standard links to SIST EN 61558-2-20:2001, SIST EN IEC 61558-2-20:2025, SIST EN IEC 61558-1:2019, SIST EN 61558-2-20:2001. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
SIST EN 61558-2-20:2011 is associated with the following European legislation: EU Directives/Regulations: 2006/95/EC, 2014/35/EU. When a standard is cited in the Official Journal of the European Union, products manufactured in conformity with it benefit from a presumption of conformity with the essential requirements of the corresponding EU directive or regulation.
SIST EN 61558-2-20:2011 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
01-april-2011
1DGRPHãþD
SIST EN 61558-2-20:2001
Varnost transformatorjev, dušilk, napajalnikov in podobnih izdelkov - 2-20. del:
Posebne zahteve in preskusi za majhne reaktorje (IEC 61558-2-20:2010)
Safety of transformers, reactors, power supply units and combinations thereof - Part 2-
20: Particular requirements and tests for small reactors (IEC 61558-2-20:2010)
Sicherheit von Transformatoren, Drosseln, Netzgeräten und entsprechende
Kombinationen - Teil 2-20: Besondere Anforderungen und Prüfungen an Kleindrosseln
(IEC 61558-2-20:2010)
Sécurité des transformateurs, bobines d'inductance, blocs d'alimentation et
combinaisons de ces éléments - Partie 2-20: Règles particulières et essais pour les
petites bobines d'inductance (CEI 61558-2-20:2010)
Ta slovenski standard je istoveten z: EN 61558-2-20:2011
ICS:
29.180 Transformatorji. Dušilke Transformers. Reactors
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD
EN 61558-2-20
NORME EUROPÉENNE
February 2011
EUROPÄISCHE NORM
ICS 29.180 Supersedes EN 61558-2-20:2000
English version
Safety of transformers, reactors, power supply units and combinations
thereof -
Part 2-20: Particular requirements and tests for small reactors
(IEC 61558-2-20:2010)
Sécurité des transformateurs, bobines Sicherheit von Transformatoren, Drosseln,
d'inductance, blocs d'alimentation et Netzgeräten und entsprechende
combinaisons de ces éléments - Kombinationen -
Partie 2-20: Règles particulières et essais Teil 2-20: Besondere Anforderungen und
pour les petites bobines d'inductance Prüfungen an Kleindrosseln
(CEI 61558-2-20:2010) (IEC 61558-2-20:2010)
This European Standard was approved by CENELEC on 2011-01-02. CENELEC members are bound to comply
with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard
the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and notified
to the Central Secretariat has the same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus,
the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia,
Spain, Sweden, Switzerland and the United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Management Centre: Avenue Marnix 17, B - 1000 Brussels
© 2011 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 61558-2-20:2011 E
Foreword
The text of document 96/356/FDIS, future edition 2 of IEC 61558-2-20, prepared by IEC TC 96,
Transformers, reactors, power supply units, and combinations thereof, was submitted to the
IEC-CENELEC parallel vote and was approved by CENELEC as EN 61558-2-20 on 2011-01-02.
This European Standard supersedes EN 61558-2-20:2000.
The main changes consist of updating this part in accordance with EN 61558-1:2005.
This part has the status of a group safety publication in accordance with IEC Guide 104:1997, The
preparation of safety publications and the use of basic safety publications and group safety publications.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN and CENELEC shall not be held responsible for identifying any or all such patent
rights.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2011-10-02
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2014-01-02
This part is intended to be used in conjunction with the latest edition of EN 61558-1 and its amendments.
It is based on EN 61558-1:2005.
This part supplements or modifies the corresponding clauses in EN 61558-1, so as to convert that
publication into the European standard: Particular requirements and tests for small reactors.
Where a particular subclause of Part 1 is not mentioned in this part, that subclause applies as far as is
reasonable. Where this part states "addition", "modification" or "replacement", the relevant text of Part 1 is
to be adapted accordingly.
In this part, the following print types are used:
– requirements proper: in roman type;
– test specifications: in italic type;
– explanatory matter: in smaller roman type:
In the text of this part, the words in bold are defined in Clause 3.
Subclauses, notes, figures and tables additional to those in Part 1 are numbered starting from 101;
supplementary annexes are entitled AA, BB, etc.
Annex ZA has been added by CENELEC.
__________
- 3 - EN 61558-2-20:2011
Endorsement notice
The text of the International Standard IEC 61558-2-20:2010 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:
IEC 60289:1988 NOTE Harmonized as EN 60289:1994 (modified).
IEC 61347-2-8:2000 NOTE Harmonized as EN 61347-2-8:2001 (not modified).
IEC 61347-2-9:2000 NOTE Harmonized as EN 61347-2-9:2001 (not modified).
IEC 61558-2-16:2009 NOTE Harmonized as EN 61558-2-16:2009 (not modified).
__________
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.
Annex ZA of Part 1 is applicable except as follows:
Addition:
Publication Year Title EN/HD Year
IEC 61558-1 2005 Safety of power transformers, power supplies, EN 61558-1 2005
reactors and similar products - + corr. August 2006
Part 1: General requirements and tests
IEC 61558-2-20 ®
Edition 2.0 2010-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
GROUP SAFETY PUBLICATION
PUBLICATION GROUPÉE DE SÉCURITÉ
Safety of transformers, reactors, power supply units and combinations thereof –
Part 2-20: Particular requirements and tests for small reactors
Sécurité des transformateurs, bobines d’inductance, blocs d’alimentation et des
combinaisons de ces éléments –
Partie 2-20: Règles particulières et essais pour les petites bobines d'inductance
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
Q
CODE PRIX
ICS 29.180 ISBN 978-2-88912-038-3
– 2 – 61558-2-20 © IEC:2010
CONTENTS
FOREWORD.3
1 Scope.5
2 Normative references.6
3 Terms and definitions .6
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.11
10 Change of input voltage setting .11
11 Output voltage and output current under load .11
12 No-load output voltage.12
13 Short-circuit voltage.12
14 Heating.12
15 Short-circuit and overload protection .12
16 Mechanical strength.14
17 Protection against harmful ingress of dust, solid objects and moisture.14
18 Insulation resistance, dielectric strength and leakage current .14
19 Construction .14
20 Components .14
21 Internal wiring .15
22 Supply connection and other external flexible cables or cords.15
23 Terminals for external conductors .15
24 Provision 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 .15
28 Resistance to rusting .16
Annexes.17
Bibliography .17
61558-2-20 © IEC:2010 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SAFETY OF TRANSFORMERS, REACTORS,
POWER SUPPLY UNITS AND COMBINATIONS THEREOF –
Part 2-20: Particular requirements and tests for small reactors
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 61558-2-20 has been prepared by IEC technical committee 96:
Transformers, reactors, power supply units and combinations thereof.
This second edition cancels and replaces the first edition published in 2000. It constitutes a
technical revision. The main changes consist of updating this part in accordance with
IEC 61558-1:2005.
This part has the status of a group safety publication in accordance with IEC Guide 104:1997,
The preparation of safety publications and the use of basic safety publications and group
safety publications.
– 4 – 61558-2-20 © IEC:2010
The text of this standard is based on the following documents:
FDIS Report on voting
96/356/FDIS 96/363/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
This part is intended to be used in conjunction with the latest edition of IEC 61558-1 and its
amendments. It is based on the second edition (2005) of that standard.
This part supplements or modifies the corresponding clauses in IEC 61558-1, so as to convert
that publication into the IEC standard: Particular requirements and tests for small reactors.
A list of all parts of the IEC 61558 series, under the general title: Safety of transformers,
reactors, power supply units and combinations thereof, can be found on the IEC website.
Future standards in this series will carry the new general title as cited above. Titles of existing
standards in this series will be updated at the time of the next edition.
Where a particular subclause of Part 1 is not mentioned in this part, that subclause applies as
far as is reasonable. Where this part states "addition", "modification" or "replacement", the
relevant text of Part 1 is to be adapted accordingly.
In this part, the following print types are used:
– requirements proper: in roman type;
– test specifications: in italic type;
explanatory matter: in smaller roman type:
–
In the text of this part, the words in bold are defined in Clause 3.
Subclauses, notes, figures and tables additional to those in Part 1 are numbered starting from
101; supplementary annexes are entitled AA, BB, etc.
The committee has decided that the contents of this publication will remain unchanged until the
stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data related to
the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
NOTE The attention of National Committees is drawn to the fact that equipment manufacturers and testing
organizations may need a transitional period following publication of a new, amended or revised IEC publication in
which to make products in accordance with the new requirements and to equip themselves for conducting new or
revised tests.
It is the recommendation of the committee that the content of this publication be adopted for implementation
nationally not earlier than 12 months from the date of publication.
61558-2-20 © IEC:2010 – 5 –
SAFETY OF TRANSFORMERS, REACTORS,
POWER SUPPLY UNITS AND COMBINATIONS THEREOF –
Part 2-20: Particular requirements and tests for small reactors
1 Scope
Replacement:
This part of IEC 61558 deals with the safety of small reactors for general applications.
NOTE 1 Safety includes electrical, thermal and mechanical aspects.
Unless otherwise specified, from here onward, the term transformer or reactor covers small
reactors.
This part is applicable to stationary or portable, single-phase or polyphase, air-cooled (natural
or forced) general purpose reactors including alternating current, premagnetised and current
compensated independent or associated reactors.
The rated supply voltage does not exceed 1 000 V a.c. or 1 500V ripple-free d.c., the rated
supply frequency and the internal operational frequencies do not exceed 1 MHz.
The rated power does not exceed:
– 25 kVAR a.c. (25 kW d.c.) for single-phase reactors,
– 50 kVAR a.c. (50 kW d.c.) for poly-phase reactors.
This part is applicable to reactors without limitations of the rated power subject to an
agreement between the purchaser and the manufacturer.
This part is applicable to dry-type reactors. The windings may be encapsulated or non-
encapsulated.
This part does not apply to:
– reactors covered by IEC 60289;
– ballast for tubular fluorescent covered by IEC 61347-2-8;
– ballast for discharge lamps (excluding tubular fluorescent lamps) covered by
IEC 61347-2-9.
NOTE 2 For reactors filled with liquid dielectric or pulverised material such as sand, additional requirements are
under consideration.
NOTE 3 Attention is drawn to the following:
- for reactors 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 reactor should also be considered;
– 6 – 61558-2-20 © IEC:2010
- additional requirements in accordance with other appropriate standards and national rules may be applicable to
reactors intended for use in special environments, such as tropical environment.
NOT E 4 Norm al l y , reactors are intended to be associated with equipment for functional requirements of the
equipment or requirements by the installation
...