Preface
p. xiii
Basic Definitions and Nomenclature
p. 1
Introduction
p. 1
Basic Definitions and Nomenclature
p. 1
Basic Insulation
p. 1
Class 0 Equipment
p. 1
Class I Equipment
p. 2
Class II Equipment
p. 2
Class III Equipment
p. 2
Direct Contact
p. 2
Indirect Contact
p. 2
Disconnection of Supply
p. 2
Exposed-Conductive-Part (ECP)
p. 2
Extra-Low Voltage
p. 2
Extraneous-Conductive-Part (EXCP)
p. 3
Functional Insulation
p. 3
Ground
p. 3
IT Grounding System
p. 3
Neutral-Protective Conductor (PEN)
p. 4
Protective Bonding Conductor
p. 4
Protective Conductor (PE)
p. 4
Remote or Zero Potential
p. 4
TN Grounding System
p. 5
TN-C Grounding System
p. 5
TN-C-S Grounding System
p. 5
TN-S Grounding System
p. 5
TT Grounding System
p. 5
Prospective Touch Voltage
p. 6
Touch Voltage
p. 7
Prospective Step Voltage
p. 7
Step Voltage
p. 7
Fundamentals of Electrical Safety
p. 9
Introduction
p. 9
Protection Against Direct Contact
p. 10
Insulation of Live Parts
p. 10
Enclosures and Barriers
p. 11
Protection by Obstacles
p. 14
Additional Protection by Residual Current Devices
p. 15
Protection Against Indirect Contact
p. 18
Protection by Automatic Disconnection of Supply
p. 19
Protection Without Automatic Disconnection of Supply
p. 20
FAQs
p. 26
Endnotes
p. 26
Mathematical Principles of Electrical Safety
p. 29
Introduction
p. 29
Mathematical Definition of Safety
p. 29
Risk of Indirect and Direct Contact
p. 32
The Acceptable Residual Risk
p. 33
Safety and Risk of Basic Insulation
p. 36
Safety and Risk of Class 0 Equipment
p. 37
Safety and Risk of Class I Equipment
p. 38
Safety and Risk of Class II Equipment
p. 39
Safety and Risk of Electrical Separation
p. 41
A Qualitative Comparison Between Safety and Risk of Protective Measures
p. 42
FAQs
p. 43
Endnotes
p. 44
The Earth
p. 45
Introduction
p. 45
The Earth Resistance
p. 45
The Earth Potential
p. 49
Independent and Interacting Earth Electrodes
p. 51
Spherical Electrodes
p. 55
Voltage Exposure Upon Ground Faults
p. 59
Touch Voltage
p. 59
Extraneous-Conductive-Part (EXCP)
p. 63
Voltage or Current?
p. 65
FAQs
p. 67
Endnotes
p. 68
Effects of Electric Currents Passing Through the Human Body, and Safety Requirements p. 71
Introduction
p. 71
The Human Body as an Electrical System
p. 72
On the Electrical Nature of the Cells
p. 72
Action Potential
p. 73
Influence of Frequency on the Effects of Current
p. 76
Physiological Response to Electrical Currents
p. 77
Tetanization
p. 77
Ventricular Fibrillation
p. 78
Thermal Shock
p. 79
Permissible Body Current and Person's Body Mass
p. 81
Permissible Body Current Independent of Human Size
p. 82
Heart Current Factor
p. 83
Human Body Impedance
p. 84
Current Paths
p. 86
Permissible Prospective Touch Voltage VSTp
p. 87
Effects of Direct Currents
p. 90
FAQs
p. 93
Endnotes
p. 93
TT Grounding System
p. 95
Introduction
p. 95
Voltage Exposure in TT Systems
p. 96
Protection Against Indirect Contact in TT Systems by Using Overcurrent Devices
p. 99
Protection Against Indirect Contact by Using Residual Current Devices
p. 102
Neutral-to-Ground Fault in TT Systems
p. 103
Independently Grounded ECPs in TT Systems
p. 104
Leaking-to-Ground ECPs in Three-Phase TT Systems
p. 106
Electrical Interferences in TT Systems
p. 106
The Neutral Conductor in TT Systems
p. 108
Resistance of the Utility Neutral in TT Systems
p. 109
Main Equipotential Bonding
p. 110
Should We Bond Incoming Pipes Made of Plastic?
p. 111
Should We Bond Incoming Pipes Electrically Separated by a Dielectric Joint?
p. 112
Supplementary Equipotential Bonding
p. 113
Potential Differences Among Metal Parts in Fault Conditions in TT Systems
p. 113
FAQs
p. 115
Endnotes
p. 115
TN Grounding System
p. 117
Introduction
p. 117
Why Earthing the Transformer?
p. 118
Voltage Exposure in TN-S Systems
p. 120
Ground Fault in the Vicinity of the User's Transformer
p. 121
Potential Differences Between ECPs, and Between ECPs and EXCPs in TN Systems
p. 122
Protection Against Indirect Contact in TN-S Systems by Using Overcurrent Devices
p. 123
Calculation of the Approximate Minimum Value of the Phase-to-Protective Conductor
Fault Current
p. 126
Protection Against Indirect Contact in TN-S System by Using RCDs
p. 127
Transferred Potentials Between Distribution and Final Circuits in TN Systems
p. 128
Supplementary Equipotential Bonding
p. 129
Local Earth Connection of ECPs in TN Systems
p. 130
TN-C Systems and the PEN Conductor
p. 132
The Neutral Conductor in TN Systems
p. 134
The Touch Voltage in TN Systems
p. 135
Step Voltage
p. 139
A Comparison Between the Dangerousness of Touch and Step Voltages
p. 140
FAQs
p. 141
Endnotes
p. 141
Protective Multiple Earthing (TN-C-S Grounding System)
p. 143
Introduction
p. 143
Fault-Loop Impedance in PME Systems
p. 146
Energization of the PEN Conductor in PME Systems
p. 146
Ground Fault on the Low-Voltage Utility Distribution System
p. 146
Ground Fault on the Medium-Voltage Utility Distribution System
p. 148
Faults Phase-to-PEN in Low-Voltage PME Networks
p. 149
Interruption of the PEN Conductor in PME
p. 150
Stray Currents
p. 151
Stray Voltages
p. 152
Endnotes
p. 153
IT Grounding System
p. 155
Introduction
p. 155
Insulation Monitoring Device
p. 158
Equipotential Bonding
p. 159
Overvoltages Due to Faults in IT Systems
p. 159
Resonant Faults in IT Systems
p. 161
Protection Against Direct and Indirect Contact by Using RCDs in IT Systems
p. 163
Protection Against Indirect Contact in the Event of a Second Fault to Ground
p. 164
ECPs Earthed Individually or in Groups
p. 164
ECPs Earthed Collectively to a Single Grounding System
p. 165
Role of the Fault Resistance in TT and IT Systems
p. 167
FAQ
p. 170
Endnote
p. 170
Extra-Low-Voltage Systems
p. 171
Introduction
p. 171
Separated Extra-Low-Voltage (SELV) Systems
p. 172
Protection Against Indirect Contact
p. 172
Protection Against Direct Contact
p. 174
Protective Extra-Low-Voltage (PELV) Systems
p. 175
Application of PELV Systems to Control Circuits
p. 176
Functional Extra-Low-Voltage (FELV) Systems
p. 178
Endnotes
p. 180
Earth Electrodes, Protective Conductors, and Equipotential Bonding Conductors
p. 181
Introduction
p. 181
Earth Electrodes
p. 182
Corrosion Phenomena
p. 183
Protective Conductors
p. 185
Analytical Calculation of the Minimum Cross-Sectional Area of PEs
p. 186
Metallic Layers of Cables as Protective Conductor
p. 192
Equipotential Bonding Conductors
p. 193
Where Should We Use Equipotential Bonding Conductors?
p. 195
Earthing Conductors and Main Earthing Terminal
p. 196
The PEN Conductor
p. 197
FAQs
p. 198
Endnotes
p. 199
Safety Against Overvoltages
p. 201
Introduction
p. 201
Temporary Overvoltages and Safety
p. 202
High-Voltage Ground Faults in TN Systems
p. 202
High-Voltage Ground Faults in TT Systems
p. 204
High-Voltage Ground Faults in IT Systems
p. 206
External Overvoltages
p. 208
Characterization of Earthing Systems Under Impulse Conditions
p. 209
Induced Overvoltages
p. 210
Endnotes
p. 212
Safety Against Static Electricity
p. 213
Introduction
p. 213
Generation of Static Electricity
p. 215
Static Charge Energy
p. 216
Mitigation Strategies
p. 218
Residual Voltages
p. 219
Endnotes
p. 222
Testing the Electrical Safety
p. 223
Introduction
p. 223
Soil Resistivity Measurement
p. 223
Earth Resistance Measurement
p. 226
Earth Resistance Measurements in Industrial Facilities
p. 228
Earth Resistance Measurement in TT Systems
p. 230
Measurement of the Fault-Loop Impedance in TN Systems
p. 232
Touch Voltage Measurement in TN Systems (Low-Voltage Earth Faults)
p. 234
Step and Touch Voltage Measurements in TN Systems
p. 235
Fundamental Measurements in IT Systems
p. 238
Protective Conductor Continuity Test
p. 239
Insulation Resistance Test
p. 240
Endnotes
p. 242
Applications of Electrical Safety in Special Locations and Installations
p. 243
Introduction
p. 243
Electrical Safety in Marinas
p. 244
Electrical Safety Requirements for Equipment Having High Protective Conductor
Currents
p. 246
Electrical Safety in Train Stations
p. 248
Electrical Safety in Swimming Pools
p. 250
Electrical Safety in Restrictive Conductive Locations
p. 252
Electrical Safety in External Lighting Installations
p. 253
Electrical Safety in Medical Locations
p. 254
Microshock
p. 254
Leakage Currents
p. 255
Local Equipotential Earthing Connection
p. 256
Electrical Separation
p. 257
Endnotes
p. 262
Sinusoids and Phasors
p. 263
Sinusoids
p. 263
Phasors
p. 267
Endnotes
p. 272
Fundamental Conventions and Electric Circuit Theorems
p. 273
Introduction
p. 273
Fundamental Electrical Conventions
p. 273
Kirchhoff's Laws
p. 274
Voltage and Current Dividers
p. 275
Superposition Principle
p. 276
Thevenin's Theorem
p. 277
Millman's Theorem
p. 278
Impedance Bridge
p. 278
Endnote
p. 279
Fundamental Units, Symbols, and Correct Spellings
p. 281
Synoptic Table
p. 281
Index
p. 283
Table of Contents provided by Blackwell's Book Services and R.R. Bowker. Used with permission.