IEC_60076-21-2011.pdf

IEC 60076-21 Edition 1.0?2011-12 INTERNATIONAL STANDARD Power transformers Part 21:Standard requirements,terminology,and test code for step-voltage regulators IEC 60076-21:2011(E)IEEE Std.C57.15-2009 IEEE Std C57.15 Copyrighted material licensed to BR Demo by Thomson Reuters(Scientific),Inc.,,downloaded on Nov-28-2014 by James Madison.No further reproduction or distribution is permitted.Uncontrolled when printed.THIS PUBLICATION IS COPYRIGHT PROTECTED Copyright 2009 IEEE All rights reserved.IEEE is a registered trademark in the U.S.Patent&Trademark Office,owned by the Institute of Electrical and Electronics Engineers,Inc.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 the IEC Central Office.Any questions about IEEE copyright should be addressed to the IEEE.Enquiries about obtaining additional rights to this publication and other information requests should be addressed to the IEC or your local IEC member National Committee.IEC Central Office The Institute of Electrical and Electronics Engineers,Inc 3,rue de Varemb 3 Park Avenue CH-1211 Geneva 20 US-New York,NY10016-5997 Switzerland USA Email:inmailiec.ch Email:stds-infoieee.org Web:www.iec.ch Web:www.ieee.org 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.?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to search by a variety of criteria(reference number,text,technical committee,).It also gives information on projects,withdrawn and replaced publications.?IEC Just Published:www.iec.ch/online_news/justpub Stay up to date on all new IEC publications.Just Published details twice a month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.?Electropedia:www.electropedia.org The worlds 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.?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:csciec.ch Tel.:+41 22 919 02 11 Copyrighted material licensed to BR Demo by Thomson Reuters(Scientific),Inc.,,downloaded on Nov-28-2014 by James Madison.No further reproduction or distribution is permitted.Uncontrolled when printed.IEC 60076-21 Edition 1.0?2011-12 INTERNATIONAL STANDARD Power transformers Part 21:Standard requirements,terminology,and test code for step-voltage regulators INTERNATIONAL ELECTROTECHNICAL COMMISSION XD ICS 29.180 PRICE CODE ISBN 978-2-88912-848-8 IEEE Std C57.15 Copyrighted material licensed to BR Demo by Thomson Reuters(Scientific),Inc.,,downloaded on Nov-28-2014 by James Madison.No further reproduction or distribution is permitted.Uncontrolled when printed.i IEC 60076-21:2011(E)IEEE Std C57.15-2009 Published by the IEC under licence from IEEE.2009 IEEE.All rights reserved.Contents 1.Overview.1 1.1 Scope.1 1.2 Purpose.1 1.3 Word usage.1 2.Normative references.2 3.Definitions.3 4.Service conditions.9 4.1 Usual service conditions.9 4.2 Loading at other than rated conditions.10 4.3 Unusual service conditions.10 4.4 Frequency.12 5.Rating data.12 5.1 Cooling classes of voltage regulators.12 5.2 Ratings.13 5.3 Supplementary continuous-current ratings.17 5.4 Taps.18 5.5 Operating voltage limits.18 5.6 Voltage supply ratios.20 5.7 Insulation levels.20 5.8 Losses.21 5.9 Short-circuit requirements.22 5.10 Tests.23 6.Construction.24 6.1 Bushings.24 6.2 Terminal markings.25 6.3 Diagram of connections.26 6.4 Nameplates.26 6.5 Tank construction.27 6.6 Components and accessories.31 7.Other requirements.32 7.1 Other supplementary continuous-current ratings.32 7.2 Other components and accessories.32 8.Test code.33 8.1 Resistance measurements.34 8.2 Polarity test.36 8.3 Ratio tests.37 8.4 No-load losses and excitation current.40 8.5 Load losses and impedance voltage.45 8.6 Dielectric tests.51 8.7 Temperature-rise tests.64 8.8 Short-circuit tests.73 8.9 Calculated data.77 9.Control systems.81 Copyrighted material licensed to BR Demo by Thomson Reuters(Scientific),Inc.,,downloaded on Nov-28-2014 by James Madison.No further reproduction or distribution is permitted.Uncontrolled when printed.IEC 60076-21:2011(E)ii IEEE Std C57.15-2009 Published by the IEC under licence from IEEE.2009 IEEE.All rights reserved.9.1 General.81 9.2 Control device construction.81