IEC_61558-2-4-2021.pdf

IEC 61558-2-4 Edition 3.0 2021-05 INTERNATIONAL STANDARD Safety of transformers,reactors,power supply units and combinations thereof Part 2-4:Particular requirements and tests for isolating transformers and power supply units incorporating isolating transformers for general applications IEC 61558-2-4:2021-05(en)GROUP SAFETY PUBLICATION THIS PUBLICATION IS COPYRIGHT PROTECTED Copyright 2021 IEC,Geneva,Switzerland 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 IECs 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 Central Office Tel.:+41 22 919 02 11 3,rue de Varemb infoiec.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 The advanced search enables to find IEC publications by a variety of criteria(reference number,text,technical committee,).It also gives information on projects,replaced and withdrawn publications.IEC Just Published-webstore.iec.ch/justpublished Stay up to date on all new IEC publications.Just Published details all new publications released.Available online and once a month by email.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:salesiec.ch.IEC online collection-oc.iec.ch Discover our powerful search engine and read freely all the publications previews.With a subscription you will always have access to up to date content tailored to your needs.Electropedia-www.electropedia.org The worlds leading online dictionary on electrotechnology,containing more than 22 000 terminological entries in English and French,with equivalent terms in 18 additional languages.Also known as the International Electrotechnical Vocabulary(IEV)online.INTERNATIONAL ELECTROTECHNICAL COMMISSION ICS 29.180 IEC 61558-2-4 ISBN 978-2-8322-9790-2 GROUP SAFETY PUBLICATION Edition 3.0 2021-05 Registered trademark of the International Electrotechnical Commission INTERNATIONAL STANDARD Warning!Make sure that you obtained this publication from an authorized distributor.Safety of transformers,reactors,power supply units and combinations thereof Part 2-4:Particular requirements and tests for isolating transformers and power supply units incorporating isolating transformers for general applications 2 IEC 61558-2-4:2021 IEC 2021 CONTENTS FOREWORD.3 INTRODUCTION.6 1 Scope.7 2 Normative references.8 3 Terms and definitions.8 4 General requirements.8 5 General notes on tests.8 6 Ratings.9 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.11 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.12 24 Provisions for protective earthing.12 25 Screws and connections.12 26 Creepage distances,clearances and distances through insulation.12 27 Resistance to heat,fire and tracking.12 28 Resistance to rusting.13 Annexes.14 Bibliography.15 Table 101 Symbols indicating the kind of transformer.10 Table 102 Output voltage ratio.11 IEC 61558-2-4:2021 IEC 2021 3 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ SAFETY OF TRANSFORMERS,REACTORS,POWER SUPPLY UNITS AND COMBINATIONS THEREOF Part 2-4:Particular requirements and tests for isolating transformers and power supply units incorporating isolating 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,