IEC_60076-1ed2.1en-d.pdf

Power transformers Part 1:GeneralINTERNATIONALSTANDARDIEC60076-1Edition 2.12000-04Reference numberIEC 60076-1:1993+A1:1999(E)Edition 2:1993 consolidated with amendment 1:1999This English-language version is derived from the originalbilingual publication by leaving out all French-languagepages.Missing page numbers correspond to the French-language pages.Publication numbering As from 1 January 1997 all IEC publications are issued with a designation in the 60000 series.For example,IEC 34-1 is now referred to as IEC 60034-1.Consolidated editions The IEC is now publishing consolidated versions of its publications.For example,edition numbers 1.0,1.1 and 1.2 refer,respectively,to the base publication,the base publication incorporating amendment 1 and the base publication incorporating amendments 1 and 2.Further information on IEC publications The technical content of IEC publications is kept under constant review by the IEC,thus ensuring that the content reflects current technology.Information relating to this publication,including its validity,is available in the IEC Catalogue of publications(see below)in addition to new editions,amendments and corrigenda.Information on the subjects under consideration and work in progress undertaken by the technical committee which has prepared this publication,as well as the list of publications issued,is also available from the following:IEC Web Site(www.iec.ch)Catalogue of IEC publications The on-line catalogue on the IEC web site(www.iec.ch/searchpub)enables you to search by a variety of criteria including text searches,technical committees and date of publication.On-line information is also available on recently issued publications,withdrawn and replaced publications,as well as corrigenda.IEC Just Published This summary of recently issued publications(www.iec.ch/online_news/justpub)is also available by email.Please contact the Customer Service Centre(see below)for further information.Customer Service Centre If you have any questions regarding this publication or need further assistance,please contact the Customer Service Centre:Email:custserviec.ch Tel:+41 22 919 02 11 Fax:+41 22 919 03 00 Power transformers Part 1:GeneralFor price,see current catalogue IEC 2000 Copyright-all rights reservedNo 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 publisher.International Electrotechnical Commission,3,rue de Varemb,PO Box 131,CH-1211 Geneva 20,SwitzerlandTelephone:+41 22 919 02 11 Telefax:+41 22 919 03 00 E-mail:inmailiec.ch Web:www.iec.chINTERNATIONALSTANDARDIEC60076-1Edition 2.12000-04XCommission Electrotechnique InternationaleInternational Electrotechnical Commission PRICE CODEEdition 2:1993 consolidated with amendment 1:199960076-1 IEC:1993+A1:1999 3 CONTENTSPageFOREWORD.7Clause1Scope and service conditions.91.1Scope.91.2Service conditions.92Normative references.113Definitions.133.1General.133.2Terminals and neutral point.153.3Windings.173.4Rating.193.5Tappings.213.6Losses and no-load current.253.7Short-circuit impedance and voltage drop.253.8Temperature rise.273.9Insulation.273.10 Connections.273.11 Kinds of tests.293.12 Meteorological data with respect to cooling.314Rating.314.1Rated power.314.2Loading cycle.334.3Preferred values of rated power.334.4Operation at higher than rated voltage and/or at disturbed frequency.335Requirements for transformers having a tapped winding.335.1General Notation of tapping range.335.2Tapping voltage tapping current.Standard categories of tapping voltagevariation.Maximum voltage tapping.355.3Tapping power.Full-power tappings reduced-power tappings.415.4Specification of tappings in enquiry and order.435.5Specification of short-circuit impedance.435.6Load loss and temperature rise.456Connection and phase displacement symbols for three-phase transformers.457Rating plates.517.1Information to be given in all cases.517.2Additional information to be given when applicable.518Miscellaneous requirements.538.1Dimensioning of neutral connection.538.2Oil preservation system.538.3Load rejection on generator transformers.559Tolerances.5560076-1 IEC:1993+A1:1999 5 ClausePage10Tests.5910.1 General requirements for routine,type and special tests.5910.2 Measurement of winding resistance.6110.3 Measurement of voltage ratio and check of phase displacement.6310.4 Measurement of short-circuit impedance and load loss.6310.5 Measurement of no-load loss and current.6310.6 Measurement of the harmonics of the no-load current.6510.7 Measurement of zero-sequence impedance(s)on three-phase transformers.6510.8 Tests on on-load tap-changers.6711Electromagnetic compatibility(EMC).67Annex A(normative)Information required with enquiry and order.69Annex B(informative)Examples of specifications for transformers with tappings.75Annex C(informative)Specification of short-circuit impedance by boundaries.79Annex D(informative)Three-phase transformer co