Newnes electrical pocket book, twenty third edition

Newnes Electrical Pocket Book This Page Intentionally Left Blank Newnes Electrical Pocket Book Twenty-third edition E.A. Reeves DFH(Hons), CEng, MIEE Martin J. Heathcote BEng, CEng, FIEE OXFORD AMSTERDAM BOSTON LONDON NEW YORK PARIS SAN DIEGO SAN FRANCISCO SINGAPORE SYDNEY TOKYO Newnes An imprint of Elsevier Science Linacre House, Jordan Hill, Oxford OX2 8DP 200 Wheeler Road, Burlington, MA 01803 First published by George Newnes Ltd 1937 Twenty-second edition 1995 Twenty-third edition 2003 Copyright © 2003 E.A. Reeves and Martin J. Heathcote. All rights reserved The right of E.A. Reeves and Martin J. Heathcote to be identified as the authors of this work has been asserted in accordance with the Copyright, Designs and Patents Act 1988 No part of this publication may be reproduced in any material form (including photocopying or storing in any medium by electronic means and whether or not transiently or incidentally to some other use of this publication) without the written permission of the copyright holder except in accordance with the provisions of the Copyright, Designs and Patents Act 1988 or under the terms of a licence issued by the Copyright Licensing Agency Ltd, 90 Tottenham Court Road, London, England W1T 4LP. Applications for the copyright holder’s written permission to reproduce any part of this publication should be addressed to the publisher British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library ISBN 0 7506 4758 2 For information on all Newnes publications visit our website at www.newnespress.com Typeset by Laserwords Private Limited, Chennai, India. Printed and bound in Great Britain Contents PREFACE ix ACKNOWLEDGEMENTS xi INTRODUCTION 1 1 FUNDAMENTALS AND THEORY 2 Fundamentals; Electrostatics; Capacitors; The magnetic circuit; A.C. theory 2 PROPERTIES OF MATERIALS 21 Magnetic materials; Copper and its alloys; Aluminium and its alloys; Insulating materials; Superconductivity 3 PLASTICS AND RUBBER IN ELECTRICAL ENGINEERING 54 Properties of moulding materials; Thermosetting materials; Thermoplastics materials; Rubber in electrical engineering 4 SEMICONDUCTORS AND SEMICONDUCTOR DEVICES 66 Semiconductors; Applications of power semiconductors; Thermionic devices; Photoelectric devices 5 RECTIFIERS AND CONVERTERS 94 Introduction; Metal rectifiers; Rectifier equipments; Converting machines 6 COMPUTERS AND PROGRAMMABLE CONTROLLERS 105 Office and home computers; Security; Industrial computing; Microprocessor-based devices 7 ELECTRICITY GENERATION 112 Synchronous generator theory; Types of generator; Generator construction; Testing; Generator protection and synchronization; Connection to electrical network; Operation of generators; Excitation systems; Automatic voltage regulators; Power generation for public electricity supply; Industrial generation; High integrity power supplies; Solutions to power problems; The on line double conversion; General requirements for UPS; Rectifier/battery charger; IGBT inverter; Static switch; Monitoring and controls; Parallel configurations; Typical installation; Diesel no break systems; Solar energy 8 TRANSMISSION AND DISTRIBUTION 159 British regulations for overhead lines; Efficiency of transmission and distribution systems 9 CABLES 166 Underground cables; Underground cable constants; Wiring cables v vi 10 TRANSFORMERS AND TAPCHANGERS 181 Transformers; Tapchanging in transformers 11 TARIFFS AND POWER FACTOR 202 Tariffs; Power factor correction 12 REQUIREMENTS FOR ELECTRICAL INSTALLATIONS (BS 7671) 210 IEE Wiring Regulations (Sixteenth Edition); Changes introduced by the 2001 edition; BS 7671 : 2001 Details of Regulations; Part 1. Scope, object and fundamental principles; Part 2. Definitions; Part 3. Assessment of general characteristics; Part 4. Protection for safety; Part 5. Selection and erection of equipment; Part 6. Special installations or locations; Part 7. Inspection and testing; Conventional circuit arrangements; Limitation of earth fault loop impedance; Cable current-carrying capacities; Methods of cable support; Methods of testing 13 LIGHTING 261 Electric lamps; Interior lighting techniques; Floodlighting techniques 14 MOTORS AND CONTROL GEAR 291 D.C. motors; A.C. motors; Induction motors; Synchronous motors; Single-phase motors; Speed variation of a.c. motors; Motor dimensions; Motor control gear 15 SWITCHGEAR AND PROTECTION 342 Switchgear; Overload and fault protection; Relays and protective gear 16 HEATING AND REFRIGERATION 364 Water heating; Space heating; Thermostatic temperature control; Electric cookers; High frequency heating; Electric steam boilers; Electric hot water boilers; Lamp ovens for industry; Refrigeration and air conditioning; Air conditioning and ventilation 17 BUILDING AUTOMATION SYSTEMS 396 Realizing the potential of building management systems 18 INSTRUMENTS AND METERS 405 Ammeters and voltmeters; Wattmeters; Valve voltmeters; Shunts and series resistances; Current and voltage transformers; Energy meters; Testing of meters; Transducer systems; Multifunction instruments 19 ELECTRIC WELDING 427 Flux-shielded arc welding; Gas-shielded arc welding; Unshielded and short-time processes; Resistance welding; Radiation welding vii 20 BATTERY ELECTRIC VEHICLES 438 Battery-driven light cars; Hybrid vehicles; Fuel cell drives; Industrial vehicles 21 BATTERY SYSTEMS 445 Applications; Lead-acid batteries; Nickel-cadmium alkaline cells; Battery charging; Reference documents 22 CABLE MANAGEMENT SYSTEMS 457 Integrated systems 23 HAZARDOUS AREA ELECTRICAL WORK 471 ATEX directives; Hazardous areas; Electrical equipment; Installation, inspection and maintenance practice; Sources of further information INDEX 495 This Page Intentionally Left Blank Preface It is now seven years since the twenty-second edition of the Pocket Book was published, a rather longer interval than might be desirable in the rapidly moving and rapidly developing world of electrical technology. We now have a new editor and, as a result, the possibility of some differing emphasis. Eric Reeves’ name has become synonymous with the Pocket Book. He has been editor for over forty years covering some ten or more editions. He is now enjoying his ‘retirement’. He has left a pocket reference work that is in good shape, but inevitably as the industry moves on, the detail is constantly subject to change. In the UK, privatization of electricity supply was some six years consigned to history at the time of publication of the twenty-second edition. But much of the transformation of the industry, which now sees electricity traded as any other commodity like oil or coffee beans, has taken place over the last five or six years. Many of the companies that the Government set up in 1989 have now disappeared and the structure of the industry has changed beyond recognition. Changes now occur so rapidly that the details of the UK utilities as given in the previous edition have been dropped. The reader must now keep up with these developments by closely watching the business pages of his or her newspaper. Now, if it is more profitable to sell gas than to use it to generate electricity and sell that, utilities are happy to do this. Now, the generators, transmission lines and transformers are ‘assets’ which assist the owners in making a profit, and the staff entrusted with the care and supervision of these are ‘asset man- agers’. They may be more skilled in risk assessment and knowledgeable about failure rates and downtimes than their predecessors, but it is still necessary to retain a workforce who know about the plant and are able to ensure it can remain in safe and reliable operation. Privatization of the UK electricity supply has also led to many utilities procuring equipment overseas, particularly from Europe. This has resulted in the adoption within the UK of new approaches to many aspects of electrical equipment design and specification. In a wider context this has probably pro- vided added impetus to harmonization of standards and the acceptance of IEC and CENELEC documentation. Today’s technicians face a challenging task to keep abreast of develop- ments even within quite narrow fields and ‘continuing professional develop- ment’ is a task to be pursued by all, not simply those who wish to gain advancement in their chosen field. This is where it is hoped that this little book will remain of assistance. The danger is that it will get larger at each new edition. If it is to remain a handy pocket reference size, then to include new material it is necessary to leave out some information which has proved useful in the past. The hope is that the balance will remain about right and what Eric Reeves has achieved so successfully for many years will continue. One chapter which might have been left out is Chapter 6 which deals with computers. These are no longer specialist tools to be used by the few; even children in primary schools are being given computing skills. There are ix . Newnes Electrical Pocket Book This Page Intentionally Left Blank Newnes Electrical Pocket Book Twenty- third edition E.A. Reeves DFH(Hons),. Burlington, MA 01803 First published by George Newnes Ltd 1937 Twenty- second edition 1995 Twenty- third edition 2003 Copyright © 2003 E.A. Reeves and Martin J.