IEC_61892-2-2012.pdf

IEC 61892-2 Edition 2.0 2012-03 INTERNATIONAL STANDARD Mobile and fixed offshore units Electrical installations Part 2:System design IEC 61892-2:2012(E)THIS PUBLICATION IS COPYRIGHT PROTECTED Copyright 2012 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.Useful links:IEC publications search-www.iec.ch/searchpub The advanced search enables you 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by a variety of criteria(reference number,text,technical committee,).It also gives information on projects,replaced and withdrawn publications.IEC Just Published-webstore.iec.ch/justpublished Stay up to date on all new IEC publications.Just Published details all new publications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 on-line and also once a month by email.Electropedia-www.electropedia.org The worlds leading online dictionary of electronic and electrical terms containing more than 30 000 terms and definitions in English and French,with equivalent terms in additional languages.Also known as the International Electrotechnical Vocabulary(IEV)on-line.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.IEC 61892-2 Edition 2.0 2012-03 INTERNATIONAL STANDARD Mobile and fixed offshore units Electrical installations Part 2:System design INTERNATIONAL ELECTROTECHNICAL COMMISSION XC ICS 47.020.60 PRICE CODE ISBN 978-2-88912-993-5 Registered trademark of the International Electrotechnical Commission Warning!Make sure that you obtained this publication from an authorized distributor.2 61892-2 IEC:2012(E)CONTENTS FOREWORD.7 INTRODUCTION.9 1 Scope.10 2 Normative references.10 3 Terms and definitions.11 4 Sources of electrical power.16 4.1 General.16 4.2 Main source of electrical power.17 4.3 Emergency source of electrical power.18 4.4 Starting arrangements for emergency generators.21 4.5 Additional requirements for periodically unattended machinery spaces.22 4.6 General requirements for renewable sources of electrical power.22 4.6.1 Photovoltaic system.22 4.6.2 Eolic system.23 5 System earthing.23 5.1 General.23 5.2 General requirements.23 5.3 Neutral earthing methods.24 5.4 Neutral earthing for systems up to and including 1 000 V a.c.24 5.5 Neutral earthing for systems above 1 000 V.25 5.6 Generators operated in parallel with source transformers.25 5.7 Earthing resistors,connection to hull/structure.25 6 Distribution systems.27 6.1 DC distribution systems.27 6.1.1 Types of distribution systems.27 6.1.2 TN d.c.systems.28 6.1.3 IT d.c.systems.31 6.1.4 DC voltages.31 6.2 AC distribution systems.32 6.2.1 Primary a.c.distribution systems.32 6.2.2 Secondary a.c.distribution systems.32 6.2.3 TN a.c.systems.32 6.2.4 IT a.c.systems.34 6.2.5 AC voltages and frequencies.34 6.2.6 Control voltage.36 7 Distribution system requirements.37 7.1 Earthed distribution systems.37 7.2 Methods of distribution.37 7.3 Balance of loads.37 7.3.1 Balance of load on three-wire d.c.systems.37 7.3.2 Balance of loads in three-or four-wire a.c.systems.37 7.4 Final circuits.37 7.4.1 General.37 7.4.2 Final circuits for lighting.37 7.4.3 Final circuit for lighting in accommodation spaces.38 61892-2 IEC:2012(E)3 7.4.4 Final circuits in offices and workshops.38 7.4.5 Final circuits for heating.38 7.5 Control circuits.38 7.5.1 Supply systems and nominal voltages.38 7.5.2 Circuit design.38 7.5.3 Motor control.38 7.5.4 Protection.38 7.5.5 Arrangement of circuits.39 7.6 Socket-outlets.39 7.7 Shore connections for mobile units.39 7.8 Motor circuits.39 7.8.1 Starting of motors.39 7.8.2 Means of disconnection.40 7.8.3 Starters remote from motors.40 7.8.4 Master-starter system.40 8 Diversity(demand)factors.40 8.1 Final circuits.40 8.2 Circuits other than final circuits.40 8.3 Application of diversity(demand)factors.40 8.4 Motive power circuits General.40 9 System study and calculations.41 9.1 General.41 9.2 Electrical load study.42 9.3 Load flow calculations.42 9.4 Sh