IEC_TS_60871-3-2015.pdf

IEC TS 60871-3 Edition 2.0 2015-06 TECHNICA L SPECIFICA TION Shunt capacitors for A C power sy stems having a rated voltage above 1 000 V Part 3:Protection of shunt capacitors and shunt capacitor banks IEC TS 60871-3:2015-06(en)Copyright International Electrotechnical Commission THIS PUBLICATION IS COPYRIGHT PROTECTED Copyr ight 2015 IEC,Geneva,Switzer land All r ights r eserved.Unless otherwise specif ied,no par t of this publication may be reproduced or utilized in any f orm or by any means,electr onic or mechanical,including photocopying and microfilm,without permission in writing f rom 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 f or fur ther information.IEC Central Office Tel.:+41 22 919 02 11 3,r ue de Varemb Fax:+41 22 919 03 00 CH-1211 Geneva 20 infoiec.ch Switzer land www.iec.ch About the IEC The Inter national Electrotechnical Commission(IEC)is the leading global organization that prepares and publishes International Standar ds f or all electr ical,electronic and related technologies.About IEC publications The technical content of IEC publications is kept under constant review by the IEC.Please make sur e that you have the latest edition,a corrigenda or an amendment might have been published.IEC Catalogue-webstore.iec.ch/cat alogue The stand-alone application for consulting the entir e bibliographical information on IEC International Standards,Technical Specifications,Technical Reports and other documents.Available for PC,Mac OS,Android Tablets and iPad.IEC publicat ions search-w w w.iec.ch/sear chpub 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 withdraw n publications.IEC Just Published-webstore.iec.ch/just published 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 dictionar y of electronic and electrical terms containing more than 30 000 terms and definitions in English and French,with equivalent terms in 15 additional languages.A lso k now n as the International Electrotechnical V ocabular y (IEV)online.IEC Glossar y -st d.iec.ch/glossar y More than 60 000 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 Cust omer Ser v ice Centre-webst ore.iec.ch/csc If you wish to give us y our feedback on this publication or need fur ther assistance,please contact the Customer Service Centre:csciec.ch.Copyright International Electrotechnical Commission IEC TS 60871-3 Edition 2.0 2015-06 TECHNICA L SPECIFICA TION Shunt capacitors for A C power sy stems having a rated voltage above 1 000 V Part 3:Protection of shunt capacitors and shunt capacitor bank s INTER NATIONA L ELECTROTECHNICA L COMMISSION ICS 29.240.99;31.060.70 ISBN 978-2-8322-2755-8 Registered t rademark of t he Int ernational Electrot echnical Commission Warning!Make sure that you obtained this publication from an authorized distributor.Copyright International Electrotechnical Commission 2 IEC TS 60871-3:2015 IEC 2015 CONTENTS FOREWORD.5 1 Scope.7 2 Normative ref erences.7 3 Terms and def initions.7 4 Internal f uses.7 4.1 General.7 4.2 Fuse characteristics.8 4.2.1 Rated current.8 4.2.2 Rated discharge capability.8 4.2.3 Disconnecting capability.8 4.2.4 Voltage withstand capability af ter operation.8 4.3 Inf luence of capacitor element conf iguration on capacitor lif e.8 4.3.1 Capacitor with all elements connected in parallel.8 4.3.2 Capacitor with elements connected in series and parallel.8 5 External f uses.8 5.1 General.8 5.2 Fuse characteristics.9 5.2.1 Rated current.9 5.2.2 Rated voltage.9 5.2.3 Time-current characteristics.9 5.2.4 Discharge capability.10 5.3 Fuse types.10 5.3.1 General.10 5.3.2 Expulsion f uses.10 5.3.3 Current-limiting f uses.11 5.3.4 Combination current-limiting/expulsion f uses.11 5.4 Inf luence of capacitor bank conf iguration on f use selection.11 5.4.1 Single series section grounded star and delta banks.11 5.4.2 Single series section ungrounded star banks.11 5.4.3 Multiple series section banks.11 5.5 Coordination with case rupture curves.11 6 Unbalance detection.12 6.1 Operation.12 6.2 Types of unbalance protection.12 6.2.1 Neutral current(Figure 3).12 6.2.2 Neutral voltage(Figure 4).12 6.2.3 Current unbalance between neutrals(Figure 5).13 6.2.4 Phase voltage unbalance(Figure 6).13 6.2.5 Voltage dif f erence(Figure 7).13 6.2.6 Current unbalance in bridge connection(Figure 8).13 6.3 Current and voltage transf ormers.13 6.3.1 Current