Electrical Contractors Association (ECA) - Guide to the IET Wiring Regulations: IET Wiring Regulations (BS 7671: 2008 incorporating Amendment No 1: 2011)

This edition first published 2012

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Library of Congress Cataloging-in-Publication Data

Guide to the IET wiring regulations : 17th edition IET wiring regulations (BS 7671:2008 incorporating Amendment no. 1:2011) / Electrical Contractors Association.

p. cm.

Includes bibliographical references and index.

ISBN 978-1-119-96514-5 (pbk.)

ISBN 978-1-119-94075-3 (epdf)

ISBN 978-1-119-94169-9 (epub)

ISBN 978-1-119-94170-5 (mobi)

1. Electric wiringInsurance requirementsHandbooks, manuals, etc. 2. Electric wiring, InteriorHandbooks, manuals, etc. I. Electrical Contractors Association (Great Britain)

TK3275.G85 2012

621.319'24dc23

2011047222

A catalogue record for this book is available from the British Library.

Paper ISBN: 9781119965145

Foreword by Giuliano Digilio

Head of Technical Services, Electrical Contractors Association (ECA)

Amendment No. 1:2011 of the IEE Wiring Regulations BS 7671:2008 includes a name change; they are now known as the IET Wiring Regulations BS 7671:2008 Amd No. 1:2011.

The IEE Wiring Regulations, and more lately BS 7671, have always been important for electrical contractors and for installation designers, and they are a key factor in the implementation of electrical safety within the UK and indeed overseas. The IEE Wiring Regulations go back to the end of the 19th century, almost to the time of the very first electrical installation within the UK.

The ECA is fully committed to the development of standards for the national BS 7671 committee as well as corresponding work in both the European Committee for Electrotechnical Standardisation (CENELEC) and the International Electrotechnical Commission (IEC). This includes a considerable amount of work in the preparation for BS 7671:2008 Amd No. 1:2011.

I am pleased that you have purchased the ECAs Guide to the IET Wiring Regulations and I trust that this quality publication will aid to enhance the understanding and knowledge within the electrical industry for both electrical contractors and electrical designers.

Preface

This guide discusses the requirements of BS 7671:2008 including Amendment No. 1:2011, also known as the IET Wiring Regulations 17th Edition.

It has been published by the Electrical Contractors Association to help their members and the contracting industry at large to understand and apply the IET Wiring Regulations.

This guide is a valuable resource for all users of BS 7671 including apprentices and electricians who perhaps want to dig a bit deeper into the background of the Regulations, together with electrical technicians, installation engineers and design engineers. Most individuals who have any involvement with BS 7671 will find the book of considerable help and benefit in their everyday work.

Steve Mitchell

Divisional Director

Electrical Contractors Association

Acknowledgements

The ECA are very pleased to acknowledge the contribution made to this revision of the guide by Giuliano Digilio, Head of Technical Services and Graeme Wool, Principal Engineer.

Paul Cook, former staff member of the IET, is thanked for his assistance with the reviewing and updating work on this publication in line with Amendment No. 1 of BS 7671:2008 Requirements for Electrical Installations.

Steve Mitchell

Divisional Director

Electrical Contractors Association

A
BS 7671:2008 Amd No. 1:2011 Requirements for Electrical Installations Introduction and Overview

A 1 Introduction to BS 7671:2008

BS 7671:2008 Requirements for Electrical Installations was published in January 2008, and amendments were incorporated in 2011.

Although the document is a British Standard, it is also known (and jointly labelled as) as the IET Wiring Regulations Seventeenth Edition.

Throughout this book, BS 7671:2008 incorporating Amendment No. 1:2011 is referred to as BS 7671:2008, BS 7671, the Wiring Regulations, the Regulations, the 17th edition or the Standard, depending upon the particular context.

The British National Committee is obliged to publish the technical intent of the CENELEC harmonization documents (HDs). However the committee have gone further and published the HDs verbatim, except where there is a more up to date International Electrotechnical Commission (IEC) standard and, in a few instances, where national circumstances warrant changes.

The general structure of IEC, CENELEC and BS 7671 is illustrated in Figure .

Installation standards at International, European and National levels

Most of the document originates from CENELEC in harmonized documents (HDs). The parent document is known as the HD 60384 series and includes virtually all parts of the installation standard.

Within BS 7671:2008 there are now only a few regulations that are truly UK only, although some of the CENELEC parts of HD 60384 have been modified, cut, or expanded upon for BS 7671. Some of the appendices of BS 7671 are home grown.

The Wiring Regulations Committee has also used certain parts of the corresponding IEC document IEC 60364, either modified or virtually unmodified.

A list of the parts of the HD 60384 series used in BS 7671:2008 is shown in Table .

CENELEC HD 60384 and IEC 6-364 documents used in BS 7671:2008.

A 2 Plan and Layout of BS 7671:2008