Electrical Installation Designs

by Atkinson, Bill; Lovegrove, Roger; Gundry, Gary

• ISBN13: 9781119992844
• ISBN10: 1119992842
• Edition: 4th
• Format: Paperback
• Copyright: 2013-02-11
• Publisher: Wiley

Summary

A practical and highly popular guide for electrical contractors of small installations, now fully revised in accordance with the latest wiring regulations The book is a clearly written practical guide on how to design and complete a range of electrical installation projects in a competitive manner, while ensuring full compliance with the new Wiring Regulations (updated late 2008). The updated regulations introduced changes in terminology, such as 'basic' and 'fault protection', and also changed the regulation numbers. This new edition reflects these changes. It discusses new sections covering domestic, commercial, industrial and agricultural projects, including material on marinas, caravan sites, and small scale floodlighting. This book provides guidance on certification and test methods, with full attention given to electrical safety requirements. Other brand new sections cover protective measures, additional protection by means of RCDs, the new cable guidelines for thin wall partitions and Part P of the Building Regulations. Provides simple, practical guidance on how to design electrical installation projects, including worked examples and case studies Covers new cable guidelines and Part P of the Building Regulations (Electrical Installations) in line with 17th edition of the Wiring Regulations BS 7671:2008 New chapters on protective measures and additional protection by means of RCDs (residual current devices) Features new wiring projects such as marinas, caravan sites and small scale floodlighting and street lighting Fully illustrated, including illustrations new to the fourth edition

Author Biography

Mr. Bill Atkinson (deceased) Bill Atkinson was the writer's pseudonym used by Alan Smith, the original author of the book. He worked in the electrical installation industry and at the NICEIC.

Mr. Roger Lovegrove, Consultant, Surrey, UK Roger Lovegrove is an electrical consultant. He is a member of the Electrical Contractors' Association techinical committees and of the joint IEE/BSI Wiring Regulations committee. With his vast knowledge in this area of electrical engineering, he has updated Bill Atkinson’s original text for this fourth edtition.

Mr. Gary Gundry,   Senior Engineer, Electrical Safety Council, UK Mr Gundry worked for Seeboard and Eastern Electricity, before becoming a lecturer at Lowestoft College, teaching electrical contracting and electrical engineering up to HNC level. He joined NICEIC in 1999 after spending three years as a Director and Qualified Supervisor of a business enrolled as an Approved Contractor, where he worked in the Standards division on the NICEIC Technical Manual. He is now Senior Engineer at Electrical Safety Council.

Mr. Martyn Allen, Senior Engineer, Electrical Safety Council Martyn Allen's experience in the electrical installation industry spans 30 years. He served an apprenticeship and worked as an electrician with British Coal, spent 16 years in engineering insurance risk management and then joined the Electrical Safety Council. He is a Chartered Electrical Engineer and Corporate Member of the IET. He is a member of the Joint Technical Committee JPEL/64 Panel C – Shock Protection and Isolation and Switching.

Table of Contents

Preface to the Fourth Edition

1 Introduction

Wiring Regulations

Competence and responsibility

Procedures

Completion

Working methods and materials

Amendments to BS 7671

Voltages

Voltage drop

2 Three Bedroom House

The bare minimum

Standards

Load assessment

Project specification

Wiring systems and cable sizes

Circuit protection

Earth leakage protection

Arrangement of circuits

Main switch

Earthing and bonding

3 A Block of Retirement Flatlets

Early considerations

Other interested parties

Building details

Part 1 - Flats

Mains distribution

Electrical requirements in flats

Load assessment and maximum demand

Wiring system

Cable sizes

Arrangement of circuits

Consumer unit

Earthing and bonding

Part 2 — Landlord's Areas

Meter cupboard

Landlord's electrical requirements

Diversity

Cable sizes and circuitry

Distribution board

Switchgear

Earthing

Emergency systems

4 Overcurrent Protection

Overload

Overload protective devices

Fault current

Fault current protection

Short-circuit rating

Earth loop impedance

Summary of circuit-breaker specification

Conclusion

5 An Architect's Office

Other interested parties

Building structure and finishes

Electrical requirements

Loading and diversity

Wiring system

Low voltage lighting

Arrangement of circuits

Distribution boards

Cable sizes

Switchgear

Earthing and bonding

Computer installations

6 A High Street Shop

Special considerations

Building structure and finishes

Electrical requirements

Loading and diversity

Phase balance

Wiring systems

Final selection and cable sizes

Distribution board

Cable sizes

Switchgear

Isolation and switching

Earthing and bonding

7 Earthing and Bonding

Terminology

Definitions

Green-and-yellow conductors

Equipotential bonding

Protective multiple earthing (PME)

Main bonding

Single fault condition

Supplementary bonding

Circuit protective conductors

Steel conduit and trunking

Steel wire armoured cable

Information Technology equipment

8 Car Service Workshop

Building structure and finishes

Electrical requirements

Health and Safety Executive Guidance and Regulations

Load assessment and maximum demand

Phase balance

Estimate of maximum demand

What about a sub-main?

Wiring systems

Arrangement of circuits

Distribution boards

Cable sizes

Isolation and switching

Earthing and bonding

9 Circuits

Lighting circuits

Socket-outlet circuits

Alternative methods

Introducing the tree

Switching and control

Comparison of systems

10 Farming and Horticulture

Why farms are different

Equipotential zones

Earthing systems

Special earthing regulations on farms with TT

systems

Earth electrodes

Alternative electrodes

Bonding

Residual current devices

Shock protection

Fire protection

Switchgear

Wiring systems

Armoured cable

Twin and earth cable

Overhead and underground wiring

Underground cables

General rules regarding farm electrical

installations

11 Isolation and Switching

Terminology

Isolation

Mechanical maintenance

Emergency switching

Accessibility of switchgear

12 A Village Sports Centre

Building details

Electricity supply and requirements

Load assessment and diversity

Wiring systems

Circuitry and cable sizing

Arrangement of circuits

Switchgear

Shock protection

Earthing

An occasional problem

13 An Indoor Swimming Pool

Special conditions

Other interested parties

Building details

Electrical requirements

Zones

Application of zoning to this project

Changing room/Shower area

Loading and diversity

Wiring systems

Cable sizes

Distribution board

110 V supply

Earthing

14 Cables and Wiring Systems

External influences

Cost considerations

Choosing suitable cable routes

Fire barriers

Hidden cables

Fire and smoke

Wiring systems and cable management

Care with wiring systems

15 Inspection, testing and certification

Regulations

Electrical installation certificate

Extensions and alterations

Limits of responsibility

Deviations and departures

Particulars of the installation

Inspections and test schedules

Inspection procedures

Testing

Continuity testing

Insulation resistance

Earth loop impedance

Prospective fault current

Operation of residual current devices

16 Caravan park

Advanced Ideas

Measures for protection against electric shock

PME must not be used for caravans

Wiring systems

Caravan pitch electrical supply equipment

Plugs and socket-outlets

17 Residual Current Devices (RCDs)

Advanced Ideas

How does an RCD work?

Fault protection

Requirements to provide additional protection by RCDs

Protection against fire

Avoiding hazards and minimising inconvenience
due to the tripping of an RCD

Ways of meeting the requirements where the RCDs
for additional protection are incorporated in a consumer unit

Labelling

18 Flood lighting project

Advanced Ideas

Protective measures

Wiringsystems

External influences

Voltage drop

19 Circuit design calculations

Advanced Ideas

Design process

Steps 1 - 5

Worked example

Index