IEC_60826-2017.pdf

IEC 60826 Edition 4.0 2017-02 INTERNATIONAL STANDARD Overhead transmission lines Design criteria IEC 60826:2017-02(en)colourinsideCopyright International Electrotechnical Commission Provided by IHS under license with IECNot for Resale,02/16/2017 21:43:08 MSTNo reproduction or networking permitted without license from IHS-,-,-THIS PUBLICATION IS COPYRIGHT PROTECTED Copyright 2017 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 Fax:+41 22 919 03 00 CH-1211 Geneva 20 infoiec.ch Switzerland 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.IEC Catalogue-webstore.iec.ch/catalogue The stand-alone application for consulting the entire bibliographical information on IEC International Standards,Technical Specifications,Technical Reports and other documents.Available for PC,Mac OS,Android Tablets and iPad.IEC publications search-www.iec.ch/searchpub 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by a variety of criteria(reference number,text,technical committee,).It also gives information on projects,replaced and withdrawn publications.IEC Just Published-webstore.iec.ch/justpublished Stay up to date on all new IEC publications.Just Published details all new publications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 also once a month by email.Electropedia-www.electropedia.org The worlds leading online dictionary of electronic and electrical terms containing 20 000 terms and definitions in English and French,with equivalent terms in 16 additional languages.Also known as the International Electrotechnical Vocabulary(IEV)online.IEC Glossary-std.iec.ch/glossary 65 000 electrotechnical terminology entries in English and French extracted from the Terms and Definitions clause of IEC publications issued since 2002.Some entries have been collected from earlier publications of IEC TC 37,77,86 and CISPR.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:csciec.ch.Copyright International Electrotechnical Commission Provided by IHS under license with IECNot for Resale,02/16/2017 21:43:08 MSTNo reproduction or networking permitted without license from IHS-,-,-IEC 60826 Edition 4.0 2017-02 INTERNATIONAL STANDARD Overhead transmission lines Design criteria INTERNATIONAL ELECTROTECHNICAL COMMISSION ICS 29.240.20 ISBN 978-2-8322-3884-4 Registered trademark of the International Electrotechnical Commission Warning!Make sure that you obtained this publication from an authorized distributor.colourinsideCopyright International Electrotechnical Commission Provided by IHS under license with IECNot for Resale,02/16/2017 21:43:08 MSTNo reproduction or networking permitted without license from IHS-,-,-2 IEC 60826:2017 IEC 2017 CONTENTS FOREWORD.7 1 Scope.9 2 Normative references.9 3 Terms,definitions,symbols and abbreviations.9 3.1 Terms and definitions.9 3.2 Symbols and abbreviations.12 4 General.15 4.1 Objective.15 4.2 System design.15 4.3 System reliability.16 5 General design criteria.16 5.1 Methodology.16 5.1.1 General.16 5.1.2 Reliability requirements.17 5.1.3 Security requirements.19 5.1.4 Safety requirements.19 5.2 Load-strength requirements.19 5.2.1 Climatic loads.19 5.2.2 Design requirements for the system.20 5.2.3 Design formula for each component.21 6 Loadings.22 6.1 Description.22 6.2 Climatic loads,wind and associated temperatures.22 6.2.1 General.22 6.2.2 Field of application.22 6.2.3 Terrain roughness.23 6.2.4 Reference wind speed VR.23 6.2.5 Assessment of meteorological measurements.24 6.2.6 Determination from gradient wind velocities.25 6.2.7 Combination of wind speed and temperatures.25 6.2.8 Number of supports subjected in wind action,effect of length of line.26 6.2.9 Unit action of the wind speed on any line component or element.26 6.2.10 Evaluation of wind loads on line components and elements.27 6.3 Climatic loads,ice without wind.34 6.3.1 Description.34 6.3.2 Ice data.34 6.3.3 Evaluation of yearly maximum ice load by means of meteorological data analysis.35 6.3.4 Reference limit ice load.36