Tibor Horvath is a Professor Emeritus at the Budapest University of Technology and Economics. He has authored 17 books  on high voltage engineering, insulations, static electricity, measurements and testing & the history of electrotechnics, and over 120 journal articles and conference papers. He has served as president of the International Conference on Lightning Protection, and has designed lightning protection systems for many prestigious buildings including the Hungarian Parliament and the cathedral of Budapest.

"…would be used by students or as a resource for those who need to design and specify electrical protection equipment…and by anyone with an interest in lighting." (IEEE Electrical Insulation Magazine, March/April 2007)

• CHAPTERS and subsections Comment PagePREFACE xiINTRODUCTION 1Guide to use the program 11. CLOUD, CYCLONE AND FRONTS 1-0 3Development of a cloud 1-1 3Growth of a thunderstorm cloud 1-5 4Development of a cyclone 1-13 6Warm and cold fronts 1-21 7Distribution of thunderstorms 1-25 72. ELECTRIC CHARGES IN CLOUDS 2-0 9Processes of charge separation 2-1 9Charging process in the liquid phase 2-1 9Charging process during freezing 2-8 10Final distribution of charges 2-14 11Static electric field 2-16 11Relation to the ionosphere 2-17 123. DISCHARGE PROCESSES IN AIR 3-0 13Photon processes 3-1 13Excitation by photon 3-2 13Ionisation and absorption 3-3 14Recombination 3-4 14Electron collisions 3-6 14Excitation by electron 3-9 15Ionisation by collision 3-10 15Discharges 3-11 15Electron avalanche 3-11 15Streamer discharge 3-18 16Klydonograph 3-22 17Leader discharge 3-25 174. DEVELOPMENT OF THE LIGHTNING FLASH 4-0 19Start on drops in the cloud 4-1 19From leader to main stroke 4-5 20Multiple stroke 4-13 21CHAPTERS and subsections Comment PageUpward leader 4-16 22The Boys-camera: Principle and construction 4-22 23The Boys-camera: Operation 4-27 24Boys-record of ideal lightning 4-30 24Real Boys-records 4-36 255. PHYSICS OF THE LIGHTNING DISCHARGE 5-0 27Properties of a downward leader 5-1 27Condition of connecting leader 5-5 28Striking process 5-11 29Development of main stroke 5-13 29Multiple and upward stroke 5-15 30The current wave 5-19 30Lightning parameters 5-24 31Distribution functions 5-28 326. CURIOUS LIGHTNING PHENOMENA 6-0 35Properties of ball lightning 6-1 35Ball lightning-theories 6-7 37Resonance theory 6-10 37Quantum-theory 6-11 38Theory of magnetic vortex 6-12 38Photos of ball lightning 6-18 39Beaded lightning 6-23 40Stroke from clear sky 6-28 41Discharge to the ionosphere 6-31 417. INDUCED VOLTAGE 7-0 43Ampère’s law 7-1 43Rectangular loop + infinite conductor 7-5 44Rectangular loop + cut conductor 7-8 44Reduction to basic components 7-10 44Triangular loop 7-13 45Polygonal loop 7-16 45Induced voltage due to direct stroke 7-18 46Induced current due to direct stroke 7-23 46Induced voltage due to distant stroke 7-28 47Induced current due to distant stroke 7-35 488. DYNAMIC FORCES DUE TO LIGHTNING 8-0 51Parallel wires 8-1 51Force due to lightning on a rod struck at the top 8-8 52Force due to lightning on a horizontal wire 8-12 53Force due to lightning on a metal plate 8-15 53Force of leaded current at inversion of wire 8-18 54CHAPTERS and subsections Comment PageForce of leaded current on a tube 8-20 54Dynamic force on a console 8-22 54Slit effect 8-27 55Damage on tree 8-32 569. HEAT EFFECTS ON METAL OBJECTS 9-0 59Heating a metal plate 9-1 59Change of temperature in a metal plate 9-4 60Equations of melting a metal plate 9-9 61Crater and droplets 9-15 62Melting a wire at contact spot 9-18 62Melting a wire leading current 9-22 63Probability of melting 9-30 6410. LIGHTNING ATTACHMENT 10-0 67Point of orientation 10-1 67The striking distance 10-5 68Distribution and density functions 10-7 68The expected frequency of stroke 10-10 69The principle of calculation 10-10 69Collection space 10-17 7011. COLLECTION SPACES OF STRUCTURES 11-0 73The principle of collection space 11-1 73Dividing the collection space 11-3 74Two conductors 11-6 74Lightning rod on tower 11-9 75Air terminations of block-house 11-13 75The collection space of one mesh 11-25 7712. PROTECTIVE EFFECT ON FLAT ROOF 12-0 79Air termination systems on blockhouse 12-1 79Diagrams related to several air terminations 12-4 80Application of rolling sphere method 12-8 8113. PROTECTION OF INCLINED ROOF 13-0 83Types of air termination systems 13-1 83Attraction of roof and eaves 13-6 84Effect of electrodes on eaves 13-11 85Effect of electrodes on the edges 13-15 85Attraction of unprotected edges 13-23 87Stroke-free period 13-26 8714. RESIDUAL RISK OF LIGHTNING PROTECTION 14-0 89The flow diagram 14-1 89Equivalent area of a structure 14-2 89Cases of the point of strike 14-11 91Cases of damaging stroke 14-18 92Intercepted stroke 14-19 92CHAPTERS and subsections Comment PageStriking the roof 14-23 93Calculation of risk 14-27 94Weighting the consequences 14-28 95Resulting damage 14-38 97Resulting frequency of weighted damage 14-40 97Resulting risk 14-44 9815. CLASSIFICATION OF STRUCTURES 15-0 101Classes of structures 15-1 101Height and surroundings 15-12 103High surroundings 15-13 103Increased danger of stroke 15-18 104Classes according to height 15-26 106Effect of the soil profile 15-27 106The materials of roof 15-31 107Further classifications 15-37 10816. AIR TERMINATION SYSTEMS 16-0 111Level of risk and protection 16-1 111Construction methods 16-3 111Protective angle 16-3 111Rolling sphere 16-7 112Mesh size 16-9 112Degrees of Hungarian standard 16-12 113Natural air termination 16-13 113Simplified air termination 16-17 114Data of higher degrees 16-19 114Distance to the structure 16-21 115Forms of air terminations 16-28 11617. DOWN CONDUCTORS AND METAL OBJECTS 17-0 119Down conductors 17-1 119Calculation of current paths 17-1 119Example of current path 17-9 120Positioning along the perimeter 17-15 121Degrees of down conductors 17-17 121Forms of down conductors 17-22 122Vertical metal structures 17-26 123Dangerous loops 17-26 123Bonding metal structures 17-30 124Insulating spacers 17-34 124Elevators 17-37 12518. EARTHING OF LIGHTNING PROTECTION SYSTEM 18-0 127Degrees of earthing 18-1 127Natural earthing 18-2 127Simple earthing systems 18-5 128CHAPTERS and subsections Comment PageEarthing resistance 18-10 129Normal and enhanced systems 18-17 130Earthing by foundation 18-22 131Soil resistivity 18-27 132Measurement of earthing resistance 18-30 132Impulse earthing 18-32 13219. LIGHTNING ELECTROMAGNETIC IMPULSE 19-0 135Conductive coupling 19-1 135Inductive coupling 19-3 136Capacitive coupling 19-5 136Distribution of current 19-7 136Arriving current along a single line 19-10 137Arriving current along branching line 19-15 138Faraday holes 19-20 139Shielded entrance 19-25 139Shielded cable 19-30 140Circuit of lightning 19-32 14120. GRADED SURGE-PROTECTION 20-0 143Operation principles 20-1 143Three stage with resistors 20-6 144Influence of distance between stages 20-11 145Propagation of waves 20-19 146Waves on devices 20-27 14721. SURGE PROTECTION DEVICES 21-0 149Gas filled arrester 21-1 149Arc blowing spark gap 21-5 150Gliding spark gap 21-9 150Encapsulated arrester 21-13 151Characteristics of gaps 21-18 152The varistor 21-20 152Characteristics of varistor 21-29 153Types of protection devices 21-33 15422. INTERNAL LIGHTNING PROTECTION ZONES 22-0 157Structure of zones 22-1 157Standardised lightning parameters 22-5 158Networks of information systems 22-6 158Tray configuration 22-17 16023. CONNECTION TO ELECTRIC POWER NETWORK 23-0 161Striking the supply line 23-1 161Striking the air termination 23-10 162TT system 23-17 163Outdoor kWh box 23-22 164CHAPTERS and subsections Comment Page24. PROTECTION OF ELECTRONIC DEVICES 24-0 167Protection of personal computer 24-1 167Protection of television 24-10 169Relay station 24-16 17025. LIGHTNING MEASUREMENT AND LOCALIZATION 25-0 171Measuring of lightning current 25-1 171Magnetic card 25-2 171Magnetic link 25-5 172Shunt resistor 25-9 172Coil of Rogowski 25-13 173Reflection of the current wave 25-18 174Localising by direction finding 25-21 174Localising by pulse arrival time 25-24 175Lightning detection systems 25-28 17526. THE MANKIND IN THE THUNDERSTORM 26-0 177Danger in open air 26-1 177Danger on or beside a tree 26-5 178Step voltage 26-11 179What to do outdoors? 26-14 179Danger on a bicycle 26-18 180Danger at a car 26-22 180Danger at a truck 26-26 181Danger in water 26-30 182Danger in boats and vessels 26-34 182REFERENCES 185INDEX 189

Tibor Horvath is a Professor Emeritus at the Budapest University of Technology and Economics. He has authored 17 books  on high voltage engineering, insulations, static electricity, measurements and testing & the history of electrotechnics, and over 120 journal articles and conference papers. He has served as president of the International Conference on Lightning Protection, and has designed lightning protection systems for many prestigious buildings including the Hungarian Parliament and the cathedral of Budapest.

"…would be used by students or as a resource for those who need to design and specify electrical protection equipment…and by anyone with an interest in lighting." (IEEE Electrical Insulation Magazine, March/April 2007)

• CHAPTERS and subsections Comment PagePREFACE xiINTRODUCTION 1Guide to use the program 11. CLOUD, CYCLONE AND FRONTS 1-0 3Development of a cloud 1-1 3Growth of a thunderstorm cloud 1-5 4Development of a cyclone 1-13 6Warm and cold fronts 1-21 7Distribution of thunderstorms 1-25 72. ELECTRIC CHARGES IN CLOUDS 2-0 9Processes of charge separation 2-1 9Charging process in the liquid phase 2-1 9Charging process during freezing 2-8 10Final distribution of charges 2-14 11Static electric field 2-16 11Relation to the ionosphere 2-17 123. DISCHARGE PROCESSES IN AIR 3-0 13Photon processes 3-1 13Excitation by photon 3-2 13Ionisation and absorption 3-3 14Recombination 3-4 14Electron collisions 3-6 14Excitation by electron 3-9 15Ionisation by collision 3-10 15Discharges 3-11 15Electron avalanche 3-11 15Streamer discharge 3-18 16Klydonograph 3-22 17Leader discharge 3-25 174. DEVELOPMENT OF THE LIGHTNING FLASH 4-0 19Start on drops in the cloud 4-1 19From leader to main stroke 4-5 20Multiple stroke 4-13 21CHAPTERS and subsections Comment PageUpward leader 4-16 22The Boys-camera: Principle and construction 4-22 23The Boys-camera: Operation 4-27 24Boys-record of ideal lightning 4-30 24Real Boys-records 4-36 255. PHYSICS OF THE LIGHTNING DISCHARGE 5-0 27Properties of a downward leader 5-1 27Condition of connecting leader 5-5 28Striking process 5-11 29Development of main stroke 5-13 29Multiple and upward stroke 5-15 30The current wave 5-19 30Lightning parameters 5-24 31Distribution functions 5-28 326. CURIOUS LIGHTNING PHENOMENA 6-0 35Properties of ball lightning 6-1 35Ball lightning-theories 6-7 37Resonance theory 6-10 37Quantum-theory 6-11 38Theory of magnetic vortex 6-12 38Photos of ball lightning 6-18 39Beaded lightning 6-23 40Stroke from clear sky 6-28 41Discharge to the ionosphere 6-31 417. INDUCED VOLTAGE 7-0 43Ampère’s law 7-1 43Rectangular loop + infinite conductor 7-5 44Rectangular loop + cut conductor 7-8 44Reduction to basic components 7-10 44Triangular loop 7-13 45Polygonal loop 7-16 45Induced voltage due to direct stroke 7-18 46Induced current due to direct stroke 7-23 46Induced voltage due to distant stroke 7-28 47Induced current due to distant stroke 7-35 488. DYNAMIC FORCES DUE TO LIGHTNING 8-0 51Parallel wires 8-1 51Force due to lightning on a rod struck at the top 8-8 52Force due to lightning on a horizontal wire 8-12 53Force due to lightning on a metal plate 8-15 53Force of leaded current at inversion of wire 8-18 54CHAPTERS and subsections Comment PageForce of leaded current on a tube 8-20 54Dynamic force on a console 8-22 54Slit effect 8-27 55Damage on tree 8-32 569. HEAT EFFECTS ON METAL OBJECTS 9-0 59Heating a metal plate 9-1 59Change of temperature in a metal plate 9-4 60Equations of melting a metal plate 9-9 61Crater and droplets 9-15 62Melting a wire at contact spot 9-18 62Melting a wire leading current 9-22 63Probability of melting 9-30 6410. LIGHTNING ATTACHMENT 10-0 67Point of orientation 10-1 67The striking distance 10-5 68Distribution and density functions 10-7 68The expected frequency of stroke 10-10 69The principle of calculation 10-10 69Collection space 10-17 7011. COLLECTION SPACES OF STRUCTURES 11-0 73The principle of collection space 11-1 73Dividing the collection space 11-3 74Two conductors 11-6 74Lightning rod on tower 11-9 75Air terminations of block-house 11-13 75The collection space of one mesh 11-25 7712. PROTECTIVE EFFECT ON FLAT ROOF 12-0 79Air termination systems on blockhouse 12-1 79Diagrams related to several air terminations 12-4 80Application of rolling sphere method 12-8 8113. PROTECTION OF INCLINED ROOF 13-0 83Types of air termination systems 13-1 83Attraction of roof and eaves 13-6 84Effect of electrodes on eaves 13-11 85Effect of electrodes on the edges 13-15 85Attraction of unprotected edges 13-23 87Stroke-free period 13-26 8714. RESIDUAL RISK OF LIGHTNING PROTECTION 14-0 89The flow diagram 14-1 89Equivalent area of a structure 14-2 89Cases of the point of strike 14-11 91Cases of damaging stroke 14-18 92Intercepted stroke 14-19 92CHAPTERS and subsections Comment PageStriking the roof 14-23 93Calculation of risk 14-27 94Weighting the consequences 14-28 95Resulting damage 14-38 97Resulting frequency of weighted damage 14-40 97Resulting risk 14-44 9815. CLASSIFICATION OF STRUCTURES 15-0 101Classes of structures 15-1 101Height and surroundings 15-12 103High surroundings 15-13 103Increased danger of stroke 15-18 104Classes according to height 15-26 106Effect of the soil profile 15-27 106The materials of roof 15-31 107Further classifications 15-37 10816. AIR TERMINATION SYSTEMS 16-0 111Level of risk and protection 16-1 111Construction methods 16-3 111Protective angle 16-3 111Rolling sphere 16-7 112Mesh size 16-9 112Degrees of Hungarian standard 16-12 113Natural air termination 16-13 113Simplified air termination 16-17 114Data of higher degrees 16-19 114Distance to the structure 16-21 115Forms of air terminations 16-28 11617. DOWN CONDUCTORS AND METAL OBJECTS 17-0 119Down conductors 17-1 119Calculation of current paths 17-1 119Example of current path 17-9 120Positioning along the perimeter 17-15 121Degrees of down conductors 17-17 121Forms of down conductors 17-22 122Vertical metal structures 17-26 123Dangerous loops 17-26 123Bonding metal structures 17-30 124Insulating spacers 17-34 124Elevators 17-37 12518. EARTHING OF LIGHTNING PROTECTION SYSTEM 18-0 127Degrees of earthing 18-1 127Natural earthing 18-2 127Simple earthing systems 18-5 128CHAPTERS and subsections Comment PageEarthing resistance 18-10 129Normal and enhanced systems 18-17 130Earthing by foundation 18-22 131Soil resistivity 18-27 132Measurement of earthing resistance 18-30 132Impulse earthing 18-32 13219. LIGHTNING ELECTROMAGNETIC IMPULSE 19-0 135Conductive coupling 19-1 135Inductive coupling 19-3 136Capacitive coupling 19-5 136Distribution of current 19-7 136Arriving current along a single line 19-10 137Arriving current along branching line 19-15 138Faraday holes 19-20 139Shielded entrance 19-25 139Shielded cable 19-30 140Circuit of lightning 19-32 14120. GRADED SURGE-PROTECTION 20-0 143Operation principles 20-1 143Three stage with resistors 20-6 144Influence of distance between stages 20-11 145Propagation of waves 20-19 146Waves on devices 20-27 14721. SURGE PROTECTION DEVICES 21-0 149Gas filled arrester 21-1 149Arc blowing spark gap 21-5 150Gliding spark gap 21-9 150Encapsulated arrester 21-13 151Characteristics of gaps 21-18 152The varistor 21-20 152Characteristics of varistor 21-29 153Types of protection devices 21-33 15422. INTERNAL LIGHTNING PROTECTION ZONES 22-0 157Structure of zones 22-1 157Standardised lightning parameters 22-5 158Networks of information systems 22-6 158Tray configuration 22-17 16023. CONNECTION TO ELECTRIC POWER NETWORK 23-0 161Striking the supply line 23-1 161Striking the air termination 23-10 162TT system 23-17 163Outdoor kWh box 23-22 164CHAPTERS and subsections Comment Page24. PROTECTION OF ELECTRONIC DEVICES 24-0 167Protection of personal computer 24-1 167Protection of television 24-10 169Relay station 24-16 17025. LIGHTNING MEASUREMENT AND LOCALIZATION 25-0 171Measuring of lightning current 25-1 171Magnetic card 25-2 171Magnetic link 25-5 172Shunt resistor 25-9 172Coil of Rogowski 25-13 173Reflection of the current wave 25-18 174Localising by direction finding 25-21 174Localising by pulse arrival time 25-24 175Lightning detection systems 25-28 17526. THE MANKIND IN THE THUNDERSTORM 26-0 177Danger in open air 26-1 177Danger on or beside a tree 26-5 178Step voltage 26-11 179What to do outdoors? 26-14 179Danger on a bicycle 26-18 180Danger at a car 26-22 180Danger at a truck 26-26 181Danger in water 26-30 182Danger in boats and vessels 26-34 182REFERENCES 185INDEX 189

Tibor Horvath is a Professor Emeritus at the Budapest University of Technology and Economics. He has authored 17 books  on high voltage engineering, insulations, static electricity, measurements and testing & the history of electrotechnics, and over 120 journal articles and conference papers. He has served as president of the International Conference on Lightning Protection, and has designed lightning protection systems for many prestigious buildings including the Hungarian Parliament and the cathedral of Budapest.

"…would be used by students or as a resource for those who need to design and specify electrical protection equipment…and by anyone with an interest in lighting." (IEEE Electrical Insulation Magazine, March/April 2007)

• CHAPTERS and subsections Comment PagePREFACE xiINTRODUCTION 1Guide to use the program 11. CLOUD, CYCLONE AND FRONTS 1-0 3Development of a cloud 1-1 3Growth of a thunderstorm cloud 1-5 4Development of a cyclone 1-13 6Warm and cold fronts 1-21 7Distribution of thunderstorms 1-25 72. ELECTRIC CHARGES IN CLOUDS 2-0 9Processes of charge separation 2-1 9Charging process in the liquid phase 2-1 9Charging process during freezing 2-8 10Final distribution of charges 2-14 11Static electric field 2-16 11Relation to the ionosphere 2-17 123. DISCHARGE PROCESSES IN AIR 3-0 13Photon processes 3-1 13Excitation by photon 3-2 13Ionisation and absorption 3-3 14Recombination 3-4 14Electron collisions 3-6 14Excitation by electron 3-9 15Ionisation by collision 3-10 15Discharges 3-11 15Electron avalanche 3-11 15Streamer discharge 3-18 16Klydonograph 3-22 17Leader discharge 3-25 174. DEVELOPMENT OF THE LIGHTNING FLASH 4-0 19Start on drops in the cloud 4-1 19From leader to main stroke 4-5 20Multiple stroke 4-13 21CHAPTERS and subsections Comment PageUpward leader 4-16 22The Boys-camera: Principle and construction 4-22 23The Boys-camera: Operation 4-27 24Boys-record of ideal lightning 4-30 24Real Boys-records 4-36 255. PHYSICS OF THE LIGHTNING DISCHARGE 5-0 27Properties of a downward leader 5-1 27Condition of connecting leader 5-5 28Striking process 5-11 29Development of main stroke 5-13 29Multiple and upward stroke 5-15 30The current wave 5-19 30Lightning parameters 5-24 31Distribution functions 5-28 326. CURIOUS LIGHTNING PHENOMENA 6-0 35Properties of ball lightning 6-1 35Ball lightning-theories 6-7 37Resonance theory 6-10 37Quantum-theory 6-11 38Theory of magnetic vortex 6-12 38Photos of ball lightning 6-18 39Beaded lightning 6-23 40Stroke from clear sky 6-28 41Discharge to the ionosphere 6-31 417. INDUCED VOLTAGE 7-0 43Ampère’s law 7-1 43Rectangular loop + infinite conductor 7-5 44Rectangular loop + cut conductor 7-8 44Reduction to basic components 7-10 44Triangular loop 7-13 45Polygonal loop 7-16 45Induced voltage due to direct stroke 7-18 46Induced current due to direct stroke 7-23 46Induced voltage due to distant stroke 7-28 47Induced current due to distant stroke 7-35 488. DYNAMIC FORCES DUE TO LIGHTNING 8-0 51Parallel wires 8-1 51Force due to lightning on a rod struck at the top 8-8 52Force due to lightning on a horizontal wire 8-12 53Force due to lightning on a metal plate 8-15 53Force of leaded current at inversion of wire 8-18 54CHAPTERS and subsections Comment PageForce of leaded current on a tube 8-20 54Dynamic force on a console 8-22 54Slit effect 8-27 55Damage on tree 8-32 569. HEAT EFFECTS ON METAL OBJECTS 9-0 59Heating a metal plate 9-1 59Change of temperature in a metal plate 9-4 60Equations of melting a metal plate 9-9 61Crater and droplets 9-15 62Melting a wire at contact spot 9-18 62Melting a wire leading current 9-22 63Probability of melting 9-30 6410. LIGHTNING ATTACHMENT 10-0 67Point of orientation 10-1 67The striking distance 10-5 68Distribution and density functions 10-7 68The expected frequency of stroke 10-10 69The principle of calculation 10-10 69Collection space 10-17 7011. COLLECTION SPACES OF STRUCTURES 11-0 73The principle of collection space 11-1 73Dividing the collection space 11-3 74Two conductors 11-6 74Lightning rod on tower 11-9 75Air terminations of block-house 11-13 75The collection space of one mesh 11-25 7712. PROTECTIVE EFFECT ON FLAT ROOF 12-0 79Air termination systems on blockhouse 12-1 79Diagrams related to several air terminations 12-4 80Application of rolling sphere method 12-8 8113. PROTECTION OF INCLINED ROOF 13-0 83Types of air termination systems 13-1 83Attraction of roof and eaves 13-6 84Effect of electrodes on eaves 13-11 85Effect of electrodes on the edges 13-15 85Attraction of unprotected edges 13-23 87Stroke-free period 13-26 8714. RESIDUAL RISK OF LIGHTNING PROTECTION 14-0 89The flow diagram 14-1 89Equivalent area of a structure 14-2 89Cases of the point of strike 14-11 91Cases of damaging stroke 14-18 92Intercepted stroke 14-19 92CHAPTERS and subsections Comment PageStriking the roof 14-23 93Calculation of risk 14-27 94Weighting the consequences 14-28 95Resulting damage 14-38 97Resulting frequency of weighted damage 14-40 97Resulting risk 14-44 9815. CLASSIFICATION OF STRUCTURES 15-0 101Classes of structures 15-1 101Height and surroundings 15-12 103High surroundings 15-13 103Increased danger of stroke 15-18 104Classes according to height 15-26 106Effect of the soil profile 15-27 106The materials of roof 15-31 107Further classifications 15-37 10816. AIR TERMINATION SYSTEMS 16-0 111Level of risk and protection 16-1 111Construction methods 16-3 111Protective angle 16-3 111Rolling sphere 16-7 112Mesh size 16-9 112Degrees of Hungarian standard 16-12 113Natural air termination 16-13 113Simplified air termination 16-17 114Data of higher degrees 16-19 114Distance to the structure 16-21 115Forms of air terminations 16-28 11617. DOWN CONDUCTORS AND METAL OBJECTS 17-0 119Down conductors 17-1 119Calculation of current paths 17-1 119Example of current path 17-9 120Positioning along the perimeter 17-15 121Degrees of down conductors 17-17 121Forms of down conductors 17-22 122Vertical metal structures 17-26 123Dangerous loops 17-26 123Bonding metal structures 17-30 124Insulating spacers 17-34 124Elevators 17-37 12518. EARTHING OF LIGHTNING PROTECTION SYSTEM 18-0 127Degrees of earthing 18-1 127Natural earthing 18-2 127Simple earthing systems 18-5 128CHAPTERS and subsections Comment PageEarthing resistance 18-10 129Normal and enhanced systems 18-17 130Earthing by foundation 18-22 131Soil resistivity 18-27 132Measurement of earthing resistance 18-30 132Impulse earthing 18-32 13219. LIGHTNING ELECTROMAGNETIC IMPULSE 19-0 135Conductive coupling 19-1 135Inductive coupling 19-3 136Capacitive coupling 19-5 136Distribution of current 19-7 136Arriving current along a single line 19-10 137Arriving current along branching line 19-15 138Faraday holes 19-20 139Shielded entrance 19-25 139Shielded cable 19-30 140Circuit of lightning 19-32 14120. GRADED SURGE-PROTECTION 20-0 143Operation principles 20-1 143Three stage with resistors 20-6 144Influence of distance between stages 20-11 145Propagation of waves 20-19 146Waves on devices 20-27 14721. SURGE PROTECTION DEVICES 21-0 149Gas filled arrester 21-1 149Arc blowing spark gap 21-5 150Gliding spark gap 21-9 150Encapsulated arrester 21-13 151Characteristics of gaps 21-18 152The varistor 21-20 152Characteristics of varistor 21-29 153Types of protection devices 21-33 15422. INTERNAL LIGHTNING PROTECTION ZONES 22-0 157Structure of zones 22-1 157Standardised lightning parameters 22-5 158Networks of information systems 22-6 158Tray configuration 22-17 16023. CONNECTION TO ELECTRIC POWER NETWORK 23-0 161Striking the supply line 23-1 161Striking the air termination 23-10 162TT system 23-17 163Outdoor kWh box 23-22 164CHAPTERS and subsections Comment Page24. PROTECTION OF ELECTRONIC DEVICES 24-0 167Protection of personal computer 24-1 167Protection of television 24-10 169Relay station 24-16 17025. LIGHTNING MEASUREMENT AND LOCALIZATION 25-0 171Measuring of lightning current 25-1 171Magnetic card 25-2 171Magnetic link 25-5 172Shunt resistor 25-9 172Coil of Rogowski 25-13 173Reflection of the current wave 25-18 174Localising by direction finding 25-21 174Localising by pulse arrival time 25-24 175Lightning detection systems 25-28 17526. THE MANKIND IN THE THUNDERSTORM 26-0 177Danger in open air 26-1 177Danger on or beside a tree 26-5 178Step voltage 26-11 179What to do outdoors? 26-14 179Danger on a bicycle 26-18 180Danger at a car 26-22 180Danger at a truck 26-26 181Danger in water 26-30 182Danger in boats and vessels 26-34 182REFERENCES 185INDEX 189