IEC_TR_62066-2002.pdf

TECHNICALREPORTIEC TR 62066First edition2002-06Surge overvoltages and surge protectionin low-voltage a.c.power systems General basic informationSurtensions de choc et protection contre la foudredans les rseaux basse tension Informations gnrales fondamentalesReference numberIEC/TR 62066:2002(E)LICENSED TO MECON Limited.-RANCHI/BANGALOREFOR INTERNAL USE AT THIS LOCATION ONLY,SUPPLIED BY BOOK SUPPLY BUREAU.Publication numberingAs from 1 January 1997 all IEC publications are issued with a designation in the60000 series.For example,IEC 34-1 is now referred to as IEC 60034-1.Consolidated editionsThe 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,thebase publication incorporating amendment 1 and the base publication incorporatingamendments 1 and 2.Further information on IEC publicationsThe technical content of IEC publications is kept under constant review by the IEC,thus ensuring that the content reflects current technology.Information relating tothis publication,including its validity,is available in the IEC Catalogue ofpublications(see below)in addition to new editions,amendments and corrigenda.Information on the subjects under consideration and work in progress undertakenby the technical committee which has prepared this publication,as well as the listof publications issued,is also available from the following:IEC Web Site(www.iec.ch)Catalogue of IEC publicationsThe on-line catalogue on the IEC web site(www.iec.ch/catlg-e.htm)enablesyou to search by a variety of criteria including text searches,technicalcommittees and date of publication.On-line information is also available onrecently issued publications,withdrawn and replaced publications,as well ascorrigenda.IEC Just PublishedThis summary of recently issued publications(www.iec.ch/JP.htm)is alsoavailable by email.Please contact the Customer Service Centre(see below)forfurther information.Customer Service CentreIf you have any questions regarding this publication or need further assistance,please contact the Customer Service Centre:Email:custserviec.chTel:+41 22 919 02 11Fax:+41 22 919 03 00LICENSED TO MECON Limited.-RANCHI/BANGALOREFOR INTERNAL USE AT THIS LOCATION ONLY,SUPPLIED BY BOOK SUPPLY BUREAU.TECHNICALREPORTIECTR 62066First edition2002-06Surge overvoltages and surge protectionin low-voltage a.c.power systems General basic informationSurtensions de choc et protection contre la foudredans les rseaux basse tension Informations gnrales fondamentalesPRICE CODE IEC 2002 Copyright-all rights reservedNo part of this publication may be reproduced or utilized in any form or by any means,electronic ormechanical,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.chXFFor price,see current catalogueCommission Electrotechnique InternationaleInternational Electrotechnical Commission LICENSED TO MECON Limited.-RANCHI/BANGALOREFOR INTERNAL USE AT THIS LOCATION ONLY,SUPPLIED BY BOOK SUPPLY BUREAU.2 TR 62066 IEC:2002(E)CONTENTSFOREWORD.71Scope.92Reference documents.93Definitions.104Overvoltages in low-voltage systems.125Lightning overvoltages.135.1General.135.2Origin of lightning surge overvoltages.185.3Lightning surges transferred from MV systems.215.4Surges caused by direct flash to LV lines.235.5Lightning surges induced into LV systems.235.6Examples of induced overvoltages.255.7Overvoltages caused by flashes to the structures or in close vicinity.275.8Recapitulation on lightning overvoltages.306Switching overvoltages.316.1General.316.2Operation of circuit-breakers and switches.356.3Operation of fuses.376.4Frequency of occurrence.386.5Interactions with surge-protective devices.386.6Recapitulation on switching overvoltages.397Temporary overvoltages.407.1General.407.2Magnitude of temporary overvoltages due to MV and LV faults.407.3Temporary overvoltages due to defects in the LV electrical installation.427.4Probability of occurrence and severity of harm.427.5Recapitulation on temporary overvoltage.448System interaction overvoltages.448.1General.448.2Interaction between power system and communications system.458.3Other interactions.468.4Recapitulation on system interactions.469Observations on surge overvoltages and failure rates.469.1General.469.2Using field failure data.479.3Recapitulation of observations on failure rates.4810Considerations on system outage/equipment failure/fires.4810.1 General.4810.2 Avoiding interference in system operation.4910.3 Preventing permanent damage.4910.4 Costs of surge-related interruptions and failures.5010.5 Recapitulation on outages and failures.52LICENSED TO MECON Limited.-RANCHI/BANGALOREFOR INTERNAL USE AT THIS LOCATION ONLY,SUPPLIED BY BOOK SUPPLY BUREAU.TR 62066 IEC:2002(E)3 11Considerations on the use of surge prote