Modern wiring practice: design and installation

358 Pages·2005·10.25 MB·English

by  W E Steward

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Modern Wiring Practice
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Modern Wiring
Practice
Design and Installation
Revised edition
W. E. Steward
and
T. A. Stubbs
With technical contributions by
Trevor Marks and Steve Clarke
AMSTERDAM • BOSTON • HEIDELBERG • LONDON • NEW YORK • OXFORD
PARIS • SAN DIEGO • SAN FRANCISCO • SINGAPORE • SYDNEY• TOKYO
Newnes is an imprint of Elsevier
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Newnes
An imprint of Elsevier
Linacre House, Jordan Hill, Oxford OX2 8DP
200 Wheeler Road, Burlington, MA01803
First published 1952
Twelfth edition published 1995
Reprinted 1996, 1997, 1998, 2000, 2002 (twice), 2003
Revised and updated 2005
Copyright © 1952, 1995 W. E. Steward and T. A. Stubbs. All rights reserved.
Copyright © 1995 Trevor Marks Additional material Twelfth edition. All rights reserved.
The right of W. E. Steward and T. A. Stubbs 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
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British Library Cataloguing in Publication Data
Steward, W. E.
Modern Wiring Practice – 12Rev.ed.
I. Title II. Stubbs, T. A.
621.31924
Library of Congress Cataloguing in Publication Data
Steward, W. E. (William E.)
Modern wiring practice: design and installation/W. E. Steward
and T. A. Stubbs; with technical contributions by Trevor Marks
and Steve Clarke.— 13th ed.
p. cm.
includes index.
ISBN 0 7506 6662 5 (pbk.)
1. Electric wiring, Interior. I. Stubbs, T. A. II. Title.
TK3271.S8 1994
621.319’24—dc20 94-24608
CIP
ISBN 0 7506 6662 5
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Printed and bound in Great Britain by MPG Books Ltd, Bodmin, Cornwall
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Contents
Preface ix
Acknowledgements x
Part 1 DESIGN OF ELECTRICALINSTALLATION
SYSTEMS 1
1 Regulations governing electrical installations 3
Planning of installation work 3
The Electricity Safety, Quality and Continuity
Regulations 2002 5
IEE Wiring Regulations – BS 7671 6
The Electricity at Work Regulations 1989 12
British Standards 16
The Low Voltage Electrical Equipment (Safety)
Regulations 1989 16
Health and Safety at Work Act 1974 (reprinted 1977) 17
2 Designing an electrical installation 18
Assessment of general characteristics 18
Electromagnetic compatibility 22
Maintainability 22
Systems of supply 23
Protection for safety 27
Protection against electric shock 27
Protection against thermal effects 31
Protection against overcurrent 32
Protection against undervoltage 37
Isolation and switching 38
Circuit design 39
Summary 66
Design by computer 82
3 Tables from IEE Regulations for Electrical Installations 93
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vi Contents
4 Distribution of supplies in buildings 103
Main switchgear 106
Main switchgear for domestic installations 112
Main switchgear for industrial installations 115
Distribution boards 123
Colour identification of cables and conductors 129
Distribution circuits 132
Protective multiple earthing (PME) 133
Power factor 134
5 Design and arrangement of final circuits 137
Final circuit feeding fixed equipment or 2 Asockets 138
Final circuit feeding 13 Asockets to BS 1363 141
Final circuit for socket outlets to BS 196 147
Final circuit for socket outlets to BS EN 60309 148
Final circuits feeding fluorescent and other
types of discharge lighting 149
Final circuits feeding motors 151
Final circuits feeding cookers 159
6 Special types of installation 161
Bath and shower rooms 161
Swimming pools, paddling pools and hot air saunas 163
Off-peak heating 163
Underfloor and ramp heating 164
Installations in hazardous areas 166
Electrical installations for caravan parks and caravans 167
Installations on construction sites 169
Emergency supplies to premises 171
Fire alarms 177
Highway power supplies 177
Part 2 PRACTICALWORK 179
7 Asurvey of installation methods 181
8 Conduit systems 203
The screwed steel conduit system 203
Installation of screwed conduit 207
Protection of conduits 225
Termination of conduit at switch positions 225
Termination of conduit at other than switch
positions 226
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Contents vii
Removal of burrs from ends of conduit 227
Conduit installed in damp conditions 227
Continuity of the conduit system 228
Flexible conduit 228
Surface conduits feeding luminaires and clocks 229
Drawing cables into conduits 230
Looping in 233
Some practical hints 233
Conduit screwing machines 234
Conduit cutting 234
Checking conduit for obstructions 234
Bending conduit 235
Drilling and cutting 236
The concealed screwed conduit system 237
The light gauge unscrewed conduit system 242
Insulated conduit system 244
9 Trunking systems 251
Metallic trunking 251
Non-metallic trunking 256
Cable ducts 260
Underfloor trunking systems 261
10 Busbar and grid catenary systems 267
Busbar system 267
Grid catenary system 270
11 Power cable systems 273
Armoured, insulated and sheathed cables 273
Cable tray, cable basket and cable ladder 275
12 All-insulated wiring systems 284
Surface wiring 285
Concealed wiring 288
13 Installation of mineral insulated cables 293
14 Luminaires, switches, socket outlets and accessories 306
Ceiling roses 306
Luminaires 307
Flexible cords 308
Lampholders 309
Socket outlets and plugs 310
Switches 312
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viii Contents
15 Earthing 316
16 Inspection and testing 323
Inspection 323
Testing 324
Continuity tests 325
Insulation resistance 326
Polarity 328
Earth electrode resistance 329
Earth fault loop impedance 330
Testing residual current circuit breakers 331
Completion Certificates and Inspection
Report Forms 331
Notice of re-inspection and testing 332
Index 335
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Preface
This book surveys the broad spectrum of electrical design and instal-
lation work, and this edition has been revised to incorporate the lat-
est amendments to BS 7671 (The IEE Wiring Regulations) issued in
2004. The book is intended to supplement the various regulations
and items of legislation. It is not a replacement for them.
The book is divided into two sections: (1) design of electrical instal-
lation systems and (2) practical work. The design section attempts to
explain in simple terms the various regulations and requirements and
goes on to deal with such matters as main switchgear, distribution,
final circuits and special types of installations.
The practical sections, dealing with the most important wiring sys-
tems, is based on the author’s experience, and includes many on-site
illustrations and diagrams. The author hopes that readers will gain
much useful information from the book. Any comments on the new
edition will be most welcome.
T.A. Stubbs