Advanced electrical installation work, fourth edition

Preface vii 1 Health and safety and electrical principles 1 Introduction 1 Health and safety at work 1 The Health and Safety At Work Act 1974 2 The Management of Health and Safety at Work Regulations 1999 4 Provision and Use of Work Equipment Regulations 1998 4 The Control of Substances Hazardous to Health Regulations 1988 4 Personal Protective Equipment (PPE) at Work Regulations 1992 5 RIDDOR 7 The Control of Major Accidents and Hazards (COMAH) Regulations 1999 8 Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR) 8 The Construction (Design and Management) Regulations 1994 (CDM) 8 The Construction (Health, Safety and Welfare) Regulations 1996 9 Building Regulations – Part P 2005 9 The Electricity Safety, Quality and Continuity Regulations 2002 10 The Electricity at Work Regulations 1989 (EWR) 11 The IEE Wiring Regulations to BS 7671:2001 11 Environmental laws and regulations 12 Environmental Protection Act 1990 12 Pollution Prevention and Control Regulations 2000 13 Clean Air Act 1993 13 Controlled Waste Regulations 1998 13 Waste Electrical and Electronic Equipment (WEEE) EU Directive 2005 14 Radioactive Substances Act 1993 (RSA) 15 Dangerous Substances and Preparations and Chemical Regulations 2000 15 Noise Regulations 15 The Noise and Statutory Nuisance Act 1993 16 Noise Act 1996 16 Noise at Work Regulations 1989 16 The Environmental Health Officer 17 Laws protecting people 18 Employment Rights Act 1996 18 Health and Safety (First Aid) Regulations 1981 20 Data Protection Act 1998 20 Prejudice and discrimination 21 The Race Relations Act 1976 (RRA) and Amendment Act 2000 22 Sex Discrimination Act 1975 (SDA) 22 Disability Discrimination Act 1995 (DDA) 22 The Human Rights Act 1998 (HRA) 23 Enforcement Law Inspectors 23 In-house Safety Representatives 24 Safe and effective working practices 25 Quality systems 25 Investors in People (IiP) 27 Health and safety applications 27 VDU operation hazards 32 Manual handling 35 Personal Protective Equipment 36 Safety signs 38 Accidents at work 39 Fire control 40 First aid 42 dent reports 45 Secure electrical isolation 46 Permit-to-work system 49 The world of work 50 Good customer relationships 50 Changing work patterns 51 Electrical principles 52 Ohm’s law 52 Resistivity 53 Temperature coefficient 54 Resistors 54 Power and energy 58 Alternating waveforms 60 Magnetism 61 Electromagnetism 62 Electrostatics 67 Alternating current theory 73 Electrical machines 86 Direct current motors 86 Three-phase a.c. motors 90 Single-phase a.c. motors 94 Motor starters 95 Remote control of motors 97 Installation of motors 97 Motor maintenance 99 Power factor correction 100 Transformers 102 Transformer losses 103 Transformer efficiency 103 Transformer construction 104 Instrument transformers 106 Voltage transformers 106 Current transformers 106 Electricity supply systems 108 Low-voltage supply system 112 Industrial wiring systems 117 Cables 119 Installing cables 122 Protection of structures against lightning (BS 6651) 132 Exercises 136 2 Inspection, testing and commissioning 146 The construction industry 146 The building team 146 The electrical team 147 Designing an electrical installation 148 Legal contracts 148 Management systems 150 On-site communications 155 Construction site – safe working practice 164 Electrical safety systems 165 Direct contact protection 165 Earth fault protection 167 Residual current protection 168 Isolation and switching 168 Overcurrent protection 169 Semi-enclosed fuses (BS 3036) 170 Cartridge fuses (BS 1361) 171 Miniature circuit breakers (BS 3871) 172 Fusing factor 173 Position of protective devices 173 Disconnection time calculations 174 Time/current characteristics of protective devices 175 Discrimination 175 Earth fault loop impedance Zs 176 Size of protective conductor 178 Cable selection/calculation 179 Electrical testing 182 Moving coil instruments 182 Moving iron instruments 184 Damping 185 Making measurements 185 Range extension 187 Dynamometer wattmeter 189 Measurement of power in a three-phase circuit 189 Energy meter 190 Tong tester 191 Phase sequence testers 191 Test equipment used by electricians 191 Test procedures 193 Live testing 194 Isolation of supply 194 Inspection and testing techniques 194 Certification and reporting 206 Safe working procedures when testing 206 Portable appliance testing (PAT) 207 Commissioning electrical systems 211 Exercises 211 3 Fault diagnosis and rectification 217 Symptoms of an electrical fault 217 Causes of electrical faults 217 Fault diagnosis 219 Wiring circuits 219 Designing out faults 227 Finding the electrical fault 227 Safe working procedures 227 Live testing 227 Secure isolation of electrical supply 227 Faulty equipment – to repair or replace? 229 Selecting test equipment 229 Special situations 230 Antistatic precautions 231 Avoiding shutdown of IT equipment 232 Damage to electronic devices by ‘overvoltage’ 233 Risks associated with high frequency or large capacitive circuits 234 Presence of storage batteries 235 Safe removal of waste 236 Exercises 238 4 Electronic components 239 Electronic circuit symbols 239 Resistors 239 Capacitors 243 Inductors and transformers 247 Electromagnetic relays 248 Overcurrent protection 248 Packaging electronic components 248 Obtaining information and components 249 Semiconductor devices 249 Voltage divider 261 Rectification of a.c. 263 Smoothing 264 Stabilized power supplies 266 Electronic circuit assembly 266 Safety precautions 267 Hand-tools 267 Soldering irons and guns 267 Soldering 269 Desoldering 272 Circuit boards 272 Breadboards 275 Interconnection methods 275 Fault finding 277 Electronic test equipment 277 Test instruments 277 Analogue and digital displays 279 The multimeter 279 The ohmmeter 279 The cathode ray oscilloscope 281 Signal generators 283 Power supply unit 283 Mains electricity supply 284 Insulation tester 284 Logic gates and digital electronics 284 The AND logic gate 285 The OR gate 285 The exclusive-OR gate 286 The NOT gate 286 The NOR gate 287 The NAND gate 287 Buffers 287 Logic networks 287 Logic families 290 Working with logic 291 British Standard symbols 292 Exercises 292 Solutions to exercises 294 Appendices 296 Glossary 315 Index 325