My first task as editor is to acknowledge and thank my predecessors Alan Smith and Eric Reeves for their work in editing the three previous editions. It is to be hoped that they will not disapprove of this latest fourth edition. Since the third edition was published in 1996, developments in many aspects of the electrical installation industry have continued apace, both on the technological and Standards fronts.The revolution in electronic microtechnology has made it possible to introduce more complex technologies in protective equipment and control systems.
This, together with the rationalisation of national, European and international harmonised Standards, has led to the need to provide new guidance in some areas. So, after seven years, the time is ripe for an update to take account of such developments. Additionally, since the third edition was published, the political and financial aspects of the supply industry have further escalated, with further fragmentation. Chapter 1 therefore was particularly difficult, trying to take account of the continuous change in practice. At the time of writing this book, the replacement of the Electricity Supply Regulations 1988 (as amended) was anticipated.
The Electricity Safety, Quality, and Continuity Regulations came into force on 31 January 2003, but for the purposes of this book reference is made to the earlier Statutory Regulations. The effect of changes in the industry over the last few years has meant the update of nearly all the 23 chapters. It is not possible to highlight here particular alterations for they are too numerous. Sections dealing with the safety aspects of electrical installations, most particularly Chapter 11, naturally take into account Electricity at Work Regulations. To a great extent these statutory requirements complement BS 7671: Requirements for Electrical Installations, known as the IEE Wiring Regulations.
All chapters required some revision to take account of revisions and amendments to British and other Standards. It has to be recognised that, both on Standards and technology evolution, the target is continually moving. However, every effort has been made to bring the text as up-to-date as possible. Over recent years lighting design development has continued. Extra-low voltage luminaires continue to be used extensively for display and feature illumination. Security lighting has now become an industry in its own right, and Chapter 18 takes all these factors into account.
The declared low voltage supply has for a number of years been harmonised across Europe to 400/230 V with tolerances of +10% and -6%. Further consideration of these tolerances is expected in 2008. In Great Britain the electricity supply industry was fully nationalised on 1 April 1948. Changes were made in 1957 which created a UK structure consisting of the Central Electricity Generating Board (CEGB) responsible for major generation and transmission throughout England and Wales, twelve Area Boards responsible for distribution within their areas in England and Wales, two Scottish Boards and a Northern Ireland board responsible for both generation and distribution within their areas, and the Electricity Council which had a co-ordinating role and performed special functions in relation to research, industrial relations and finance.
Privatisation of the supply industry was implemented in England, Wales and Scotland under the 1989 Electricity Act and in Northern Ireland by the Electricity (Northern Ireland) Orders 1992. The Area Boards were replaced by twelve Regional Electricity Companies (RECs) operating distribution networks under franchises. Two companies in Scotland and one in Ireland, having transmission and distribution networks, received franchises (see Fig. 1.2). A company which holds licences under the Act and Orders is designated a public electricity supplier (PES). Most of the industry is now owned by private investors following flotation on the stock market, and returns on capital investment are now made to shareholders instead of the Government.
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