IEC 61558-1:2005

Safety of power transformers, power supplies, reactors and similar products - Part 1: General requirements and tests

This International Standard deals with safety aspects of power transformers, power supplies, reactors and similar products such as electrical, thermal and mechanical safety. This standard covers the following types of dry-type transformers, power supplies, including switch mode power supplies, and reactors, the windings of which may be encapsulated or non-encapsulated It has the status of a group safety publication in accordance with IEC Guide 104. The contents of the corrigenda of March 2008, March 2010 and April 2011 have been included in this copy.

Sécurité des transformateurs, alimentations, bobines d'inductance et produits analogues - Partie 1: Exigences générales et essais

La présente Norme internationale traite des aspects relatifs à la sécurité des transformateurs, alimentations, bobines d'inductance, et produits analogues, tels que la sécurité électrique, la sécurité thermique et la sécurité mécanique. La présente norme couvre les transformateurs secs et les alimentations ci-dessous, incluant les alimentations à découpage et bobines d'inductance, dont les enroulements peuvent être enrobés ou non enrobes Elle a le statut de publication groupée de sécurité conformément au guide CEI 104. Le contenu des corrigendas de mars 2008, mars 2010 et abril 2011 a été pris en considération dans cet exemplaire.

General Information

• Status: Published
• Publication Date: 04-Sep-2005
• ICS: 29.180 - Transformers. Reactors
• Technical Committee: TC 96 - Transformers, reactors, power supply units, and combinations thereof
• Drafting Committee: MT 1 - TC 96/MT 1
• Current Stage: DELPUB - Deleted Publication
• Completion Date: 29-Sep-2017

Relations

• Amended By: IEC 61558-1:2005/AMD1:2009 - Amendment 1 - Safety of power transformers, power supplies, reactors and similar products - Part 1: General requirements and tests
• Effective Date: 05-Sep-2023
• Corrected By: IEC 61558-1:2005/COR1:2008 - Corrigendum 1 - Safety of power transformers, power supplies, reactors and similar products - Part 1: General requirements and tests
• Effective Date: 05-Sep-2023
• Corrected By: IEC 61558-1:2005/COR3:2011 - Corrigendum 3 - Safety of power transformers, power supplies, reactors and similar products - Part 1: General requirements and tests
• Effective Date: 05-Sep-2023
• Corrected By: IEC 61558-1:2005/COR2:2010 - Corrigendum 2 - Safety of power transformers, power supplies, reactors and similar products - Part 1: General requirements and tests
• Effective Date: 05-Sep-2023
• Revised: IEC 61558-1:2017 - Safety of transformers, reactors, power supply units and combinations thereof - Part 1: General requirements and tests
• Effective Date: 05-Sep-2023
• Revises: IEC 61558-1:1997/AMD1:1998 - Amendment 1 - Safety of power transformers, power supply units and similar - Part 1: General requirements and tests
• Effective Date: 05-Sep-2023
• Revises: IEC 61558-1:1997/ISH1:2003 - Interpretation sheet 1 - Safety of power transformers, power supply units and similar - Part 1: General requirements and tests
• Effective Date: 05-Sep-2023
• Revises: IEC 61558-1:1997 - Safety of power transformers, power supply units and similar - Part 1: General requirements and tests
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 61558-1
Edition 2.0 2005-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
GROUP SAFETY PUBLICATION
PUBLICATION GROUPÉE DE SÉCURITÉ
Safety of power transformers, power supplies, reactors and similar products –
Part 1: General requirements and tests
Sécurité des transformateurs, alimentations, bobines d'inductance et produits
analogues – Partie 1: Exigences générales et essais
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 la CEI ou du Comité national de la CEI du pays du demandeur.
Si vous avez des questions sur le copyright de la CEI ou si vous désirez obtenir des droits supplémentaires sur cette
publication, utilisez les coordonnées ci-après ou contactez le Comité national de la CEI de votre pays de résidence.
IEC Central Office
3, rue de Varembé
CH-1211 Geneva 20
Switzerland
Email: [e-mail]
Web: www.iec.ch
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 corrigenda or an amendment might have been published.
ƒ Catalogue of IEC publications: www.iec.ch/searchpub
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It also gives information on projects, withdrawn and replaced publications.
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Stay up to date on all new IEC publications. Just Published details twice a month all new publications released. Available
on-line and also by email.
ƒ Electropedia: www.electropedia.org
The world's leading online dictionary of electronic and electrical terms containing more than 20 000 terms and definitions
in English and French, with equivalent terms in additional languages. Also known as the International Electrotechnical
Vocabulary online.
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Centre FAQ or contact us:
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A propos de la CEI
La Commission Electrotechnique Internationale (CEI) 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 CEI
Le contenu technique des publications de la CEI est constamment revu. Veuillez vous assurer que vous possédez
l’édition la plus récente, un corrigendum ou amendement peut avoir été publié.
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Le premier dictionnaire en ligne au monde de termes électroniques et électriques. Il contient plus de 20 000 termes et
définitions en anglais et en français, ainsi que les termes équivalents dans les langues additionnelles. Egalement appelé
Vocabulaire Electrotechnique International en ligne.
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IEC 61558-1
Edition 2.0 2005-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
GROUP SAFETY PUBLICATION
PUBLICATION GROUPÉE DE SÉCURITÉ
Safety of power transformers, power supplies, reactors and similar products –
Part 1: General requirements and tests
Sécurité des transformateurs, alimentations, bobines d'inductance et produits
analogues – Partie 1: Exigences générales et essais
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX XH
ICS 29.180 ISBN 2-8318-8170-6
61558-1 ¤ IEC:2005 – 3 – – 2 – 61558-1 © IEC:2005
CONTENTS
FOREWORD.5
INTRODUCTION.8
1 Scope.11
2 Normative references.13
3 Terms and definitions .16
4 General requirements .29
5 General notes on tests.29
6 Ratings.31
7 Classification .31
8 Marking and other information.33
9 Protection against electric shock.38
10 Change of input voltage setting .41
11 Output voltage and output current under load .42
12 No-load output voltage.42
13 Short-circuit voltage.43
14 Heating.43
15 Short circuit and overload protection .48
16 Mechanical strength.52
17 Protection against harmful ingress of dust, solid objects and moisture.55
18 Insulation resistance, dielectric strength and leakage current . . 59
19 Construction .63
20 Components . . 7 0
21 Internal wiring .76
22 Supply connection and other external flexible cables or cords.76
23 Terminals for external conductors .82
24 Provisions for protective earthing .84
25 Screws and connections .85
26 Creepage distances, clearances and distances through insulation .88
27 Resistance to heat, fire and tracking .97
28 Resistance to rusting . 1 0 1
Annex A (normative) Measurement of creepage distances and clearances. 1 0 9
Annex B (normative) Testing a series of transformers.113
Annex C (normative) Creepage distances (cr), clearances (cl) and distances through
insulation (dti) Material group II (400 ≤CTI <600) .115
Annex D (normative) Creepage distances (cr), clearances (cl) and distances through
insulation (dti) Material group I (CTI ≥600) .118
Annex E (normative) Glow-wire test.121
Annex F (normative) Requirements for manually operated switches which are parts of
transformers assembly.122

61558-1 © IEC:200561558-1 ¤ IEC:2005 – 5 – – 3 –
Annex G (normative) Tracking test .125
Annex H (normative) Electronic circuits .126
Annex I (void). 1 3 0
Annex J (normative) Measuring network for touch-currents.131
Annex K (normative) Insulated winding wires for use as multiple layer insulation. 1 3 2
Annex L (normative) Routine tests (production tests) .134
Annex M (informative) Examples to be used as a guide for 19.1 .136
Annex N (informative) Examples of points of application of test voltages.139
Annex O (void) .141
Annex P (informative) Examples of points of measurement of creepage distances and
clearances .142
Annex Q (informative) Explanation of IP numbers for degrees of protection .144
Annex R (normative) Explanations of the application of 4.1.1.2.1 of IEC 60664-1 (see
26.2) .146
Annex S (void) .147
Annex T (void) .148
Annex U (informative) Optional t –marking of transformers.149
w
Annex V (informative) Symbols to be used for thermal cut-outs.158
Annex W (normative) Coated printed circuit boards .159
Bibliography .160
Index of defined terms.161
Figure 0 – IEC 61558 principle .9
Figure 1 – Mounting box for flush-type transformer (see 5.10) . 1 0 2
Figure 2 – Standard test finger (see 9.1.2, 15.5.2 and IEC 61032, test probe B).103
Figure 3 – Test pin (see 9.2 and IEC 61032, test probe 13) .104
Figure 4 – Abrasion resistance test for insulating coated layers . 1 0 4
Figure 5 – Ball-pressure apparatus (see 27.1) .105
Figure 6 – Test arrangement for checking mechanical withstanding of insulating
materials in thin sheet layers (see 26.3) .106
Figure 7 – Flexing test apparatus (see 22.9.4) .107
Figure 8 – Test configuration: single-phase equipment on star TN or TT system .108
Figure H.1 – Example of an electronic circuit with low-power points (see H.2.2) . 1 2 9
Figure J.1 – Measuring network for touch-current . 1 3 1
Figure U.1 – Relation between winding temperature and endurance test duration.156
Figure U.2 – Assessment of claimed value of S .157

61558-1 ¤ IEC:2005 – 7 – – 4 – 61558-1 © IEC:2005
Table 1 – Values of maximum temperatures in normal use .45
Table 2 – Test temperature and testing time (in days) per cycle.47
Table 3 – Maximum values of temperatures under short-circuit or overload conditions .49
Table 4 – Values of T and k for fuses .
...

IEC 61558-1 ®
Edition 2.1 2009-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
GROUP SAFETY PUBLICATION
PUBLICATION GROUPÉE DE SÉCURITÉ
Safety of power transformers, power supplies, reactors and similar products –
Part 1: General requirements and tests

Sécurité des transformateurs, alimentations, bobines d'inductance et produits
analogues –
Partie 1: Exigences générales et essais
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 la CEI ou du Comité national de la CEI du pays du demandeur.
Si vous avez des questions sur le copyright de la CEI ou si vous désirez obtenir des droits supplémentaires sur cette
publication, utilisez les coordonnées ci-après ou contactez le Comité national de la CEI de votre pays de résidence.

IEC Central Office
3, rue de Varembé
CH-1211 Geneva 20
Switzerland
Email: [e-mail]
Web: www.iec.ch
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 corrigenda or an amendment might have been published.
ƒ Catalogue of IEC publications: www.iec.ch/searchpub
The IEC on-line Catalogue enables you to search by a variety of criteria (reference number, text, technical committee,…).
It also gives information on projects, withdrawn and replaced publications.
ƒ IEC Just Published: www.iec.ch/online_news/justpub
Stay up to date on all new IEC publications. Just Published details twice a month all new publications released. Available
on-line and also by email.
ƒ Electropedia: www.electropedia.org
The world's leading online dictionary of electronic and electrical terms containing more than 20 000 terms and definitions
in English and French, with equivalent terms in additional languages. Also known as the International Electrotechnical
Vocabulary online.
ƒ Customer Service Centre: www.iec.ch/webstore/custserv
If you wish to give us your feedback on this publication or need further assistance, please visit the Customer Service
Centre FAQ or contact us:
Email: [e-mail]
Tel.: [phone]
Fax: [phone]
A propos de la CEI
La Commission Electrotechnique Internationale (CEI) 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 CEI
Le contenu technique des publications de la CEI est constamment revu. Veuillez vous assurer que vous possédez
l’édition la plus récente, un corrigendum ou amendement peut avoir été publié.
ƒ Catalogue des publications de la CEI: www.iec.ch/searchpub/cur_fut-f.htm
Le Catalogue en-ligne de la CEI vous permet d’effectuer des recherches en utilisant différents critères (numéro de référence,
texte, comité d’études,…). Il donne aussi des informations sur les projets et les publications retirées ou remplacées.
ƒ Just Published CEI: www.iec.ch/online_news/justpub
Restez informé sur les nouvelles publications de la CEI. Just Published détaille deux fois par mois les nouvelles
publications parues. Disponible en-ligne et aussi par email.
ƒ Electropedia: www.electropedia.org
Le premier dictionnaire en ligne au monde de termes électroniques et électriques. Il contient plus de 20 000 termes et
définitions en anglais et en français, ainsi que les termes équivalents dans les langues additionnelles. Egalement appelé
Vocabulaire Electrotechnique International en ligne.
ƒ Service Clients: www.iec.ch/webstore/custserv/custserv_entry-f.htm
Si vous désirez nous donner des commentaires sur cette publication ou si vous avez des questions, visitez le FAQ du
Service clients ou contactez-nous:
Email: [e-mail]
Tél.: [phone]
Fax: [phone]
IEC 61558-1 ®
Edition 2.1 2009-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
GROUP SAFETY PUBLICATION
PUBLICATION GROUPÉE DE SÉCURITÉ
Safety of power transformers, power supplies, reactors and similar products –
Part 1: General requirements and tests

Sécurité des transformateurs, alimentations, bobines d'inductance et produits
analogues –
Partie 1: Exigences générales et essais

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CR
CODE PRIX
ICS 29.180 ISBN 978-2-88910-539-7
– 2 – 61558-1 © IEC:2005+A1:2009
CONTENTS
FOREWORD.5
INTRODUCTION.8

1 Scope.11
2 Normative references.13
3 Terms and definitions .16
4 General requirements .29
5 General notes on tests.29
6 Ratings.31
7 Classification .31
8 Marking and other information.33
9 Protection against electric shock.38
10 Change of input voltage setting .41
11 Output voltage and output current under load .42
12 No-load output voltage.42
13 Short-circuit voltage.43
14 Heating.43
15 Short circuit and overload protection .48
16 Mechanical strength.52
17 Protection against harmful ingress of dust, solid objects and moisture.55
18 Insulation resistance, dielectric strength and leakage current .59
19 Construction .63
20 Components .70
21 Internal wiring .76
22 Supply connection and other external flexible cables or cords.76
23 Terminals for external conductors .82
24 Provisions for protective earthing .84
25 Screws and connections .85
26 Creepage distances, clearances and distances through insulation .88
27 Resistance to heat, fire and tracking .97
28 Resistance to rusting .101

Annex A (normative) Measurement of creepage distances and clearances. 109
Annex B (normative) Testing a series of transformers. 113
Annex C (normative) Creepage distances (cr), clearances (cl) and distances through
insulation (dti) Material group II (400 ≤CTI <600) . 115
Annex D (normative) Creepage distances (cr), clearances (cl) and distances through
insulation (dti) Material group I (CTI ≥600) . 118
Annex E (normative) Glow-wire test. 121
Annex F (normative) Requirements for manually operated switches which are parts of
transformers assembly.122

61558-1 © IEC:2005+A1:2009 – 3 –
Annex G (normative) Tracking test . 125
Annex H (normative) Electronic circuits . 126
Annex I (void). 130
Annex J (normative) Measuring network for touch-currents. 131
Annex K (normative) Insulated winding wires for use as multiple layer insulation. 132
Annex L (normative) Routine tests (production tests) . 134
Annex M (informative) Examples to be used as a guide for 19.1 . 136
Annex N (informative) Examples of points of application of test voltages. 139
Annex O (void) . 141
Annex P (informative) Examples of points of measurement of creepage distances
and clearances. 142
Annex Q (informative) Explanation of IP numbers for degrees of protection . 144
Annex R (normative) Explanations of the application of 4.1.1.2.1 of IEC 60664-1
(see 26.2) . 146
Annex S (void) . 147
Annex T (void) . 148
Annex U (informative) Optional t –marking of transformers. 149
w
Annex V (informative) Symbols to be used for thermal cut-outs. 158
Annex W (normative) Coated printed circuit boards . 159

Bibliography . 160
Index of defined terms.161

Figure 0 – IEC 61558 principle .9
Figure 1 – Mounting box for flush-type transformer (see 5.10) . 102
Figure 2 – Standard test finger (see 9.1.2, 15.5.2 and IEC 61032, test probe B). 103
Figure 3 – Test pin (see 9.2 and IEC 61032, test probe 13) . 104
Figure 4 – Abrasion resistance test for insulating coated layers . 104
Figure 5 – Ball-pressure apparatus (see 27.1) . 105
Figure 6 – Test arrangement for checking mechanical withstanding of insulating
materials in thin sheet layers (see 26.3) . 106
Figure 7 – Flexing test apparatus (see 22.9.4) . 107
Figure 8 – Test configuration: single-phase equipment on star TN or TT system . 108
Figure H.1 – Example of an electronic circuit with low-power points (see H.2.2) . 129
Figure J.1 – Measuring network for touch-current . 131
Figure U.1 – Relation between winding temperature and endurance test duration. 156
Figure U.2 – Assessment of claimed value of S . 157

– 4 – 61558-1 © IEC:2005+A1:2009
Table 1 – Values of maximum temperatures in normal use .45
Table 2 – Test temperature and testing time (in days) per cycl
...