1.0.1 This Code is formulated in order to adopt lightning protection measures by adjusting measures to local conditions for lightning protection design of structures (including construction), prevent or reduce personal injury, cultural relics and property loss arising from lightning stroke of structures, as well as damage or error operation of electrical and electronic systems triggerred by lightning electromagnetic impulse, and thereby achieving safety and reliability, advanced technology, and economy and rationality.
1.0.2 This Code is applicable to the lightning protection design of newly-built, extended and rebuilt structures.
1.0.3 For the purpose of the lightning protection design of structures, the type of lightning protection system and its layout shall be researched in detail and determined based on earnestly investigating geography, geology, soil, weather, environment conditions and lightning activity rules as well as characteristics of protected objects.
1.0.4 In addition to this Code, the lightning protection design of structures shall also comply with those specified in the current relevant standards of the state.
2 Terms
2.0.1 Lightning flash to earth
It refers to one or multiple discharges between thundercloud and ground (including overground projection).
2.0.2 Lightning stroke
It refers to one discharge in lightning flash to earth.
2.0.3 Point of strike
It refers to that point struck by lighting flash on ground or its projection. One lighting flash may have multiple points of strike.
2.0.4 Lightning current
It refers to the current flowing through the point of strike.
2.0.5 Lightning protection system (LPS)
It is used for reducing substantive damage and personal injury arising from lighting flash on structures or structure surrounding, which consists of external lightning protection system and internal lightning protection system.
2.0.6 External lightning protection system
It consists of air-termination system, down-conductor system and earth-termination system.
2.0.7 Internal lightning protection system
It consists of lightning equipotential bonding and spacing with external lightning protection system.
2.0.8 Air-termination system
It consists of air-termination pole, air-termination strip, air-termination line, air-termination net, metal roof, metal member, etc. intercepting lighting flash.
2.0.9 Down-conductor system
It refers to the conductor used for conducting lightning current from air-termination system to earth-termination system.
2.0.10 Earth-termination system
It refers to the integration of earth electrode and earthing conductor, which is used for conducting lightning current and making it flow into earth
2.0.11 Earth electrode
It refers to the conductor buried into soil or concrete foundation and used for diffusion.
2.0.12 Earthing conductor
It refers to the bonding conductor from breaking-linking card or line exchange position to earth electrode, or the bonding conductor from earthing terminal and bonding bar to earth electrode.
2.0.13 Direct lightning flash
It refers to the lighting flash generating electrical effect, heat effect and mechanical force when directly stroking to structures, other objects, ground or external lightning protection system.
2.0.14 Lightning electrostatic induction
It refers that the action of thundercloud makes nearby conductor induct electrical charge with opposite sign as thundercloud; during main discharge of thundercloud, the electrical charge in leader channel is rapidly neutralized, and the induced charge in conductor is released, if the charge is not released into ground, a very high electrical potential will be generated.
2.0.15 Lightning electromagnetic induction
It refers that the transient strong electromagnetic field is generated in the surrounding space of lightning current due to rapid change of lightning current, which makes nearby conductor induce very high electromotive force.
2.0.16 Lightning induction
It refers to lightning electrostatic induction and lightning electromagnetic induction generated on nearby conductor during lightning discharge, which may make spark discharge generate between metal components.
2.0.17 Lightning surge
It refers to transient wave due to lightning striking to lightning protection system or line and triggerred by lightning electrostatic induction or lightning electromagnetic impulse to behave as overvoltage and overcurrent.
2.0.18 Lightning surge on incoming services
It refers that the lightning wave, namely lightning surge may penetrate into rooms along these pipelines owing to the action of lightning for overhead line, cable line or metallic pipe and may endanger personal safety or equipment damage.
2.0.19 Lightning equipotential bonding (LEB)
It refers that all separated metal objects are directly connected to lightning protection system with bonding conductor via surge protective device so as to reduce the potential difference triggerred by lightning current.
2.0.20 Bonding bar
It refers to the metal strip connecting metallic device, external conductive object, power line, telecommunication line and other lines to lightning protection system so as to make equipotential bonding with lightning protection system.
2.0.21 Bonding conductor
It refers to the conductor connecting all separated conductive objects to lightning protection system.
2.0.22 Bonding network (BN)
It refers to one network composed due to interconnection of all the conductive objects of structures and internal system (excluding live conductor).
2.0.23 Earthing system
It refers to the overall system connecting bonding network and earth-termination system. 2.0.24 Lightning protection zone (LPZ)
It refers to the zone classifying the electromagnetic environment of lightning stroke; the zone interface of one lightning protection zone does not always have physical object interface, for example, not always wall, floor ceiling as zone interface.
2.0.25 Lightning electromagnetic impulse (LEMP)
It refers to electromagnetic effect generated by lightning current through resistance, inductance and capacitance coupling, including lightning surge and radiated electromagnetic field
2.0.26 Electrical system
Contents 1 General Principles 2 Terms 3 Classification of Structures to Be Protected against Lightning 4 Protection Measures for Structures against Lightning 4. 1 Basic Requirement 4. 2 Protection Measures of The First class of Structures to be Protected against Lightning 4. 3 Protection Measures for Second Class of Structures to Be Protected against Lightning 4. 4 Lightning Protection Measures of Third Class of Structures to Be Protected against Lightning 4. 5 Other Protection Measures against Lightning 5 Lightning Protection System 5. 1 Materials for Lightning Protection System 5. 2 Air-termination System 5. 3 Down-conductor System 5. 4 Earth-termination System 6 Protection against LEMP(lightning electromagnetic impulse) 6. 1 Basic Requirement 6. 2 Lightning Pretection Zones and Protection against LEMP 6. 3 Requirements for Magnetic Shielding, Earthing and Equipotential Bonding 6. 4 Requirements for Installation and Selection of SPDS (surge protective devices) Appendix A Expected Annual Number of Lightning Flash for Structures Appendix B Structure Parts Suffered Easily By Lightening Stroke Appendix C Conversion from Power Frequency Earthing Resistance to Earthing Resistance of Earth-termination System Appendix D Determination of Protected Volume of Air-termination System with Rolling Sphere Method Appendix E Values of Coefficient kc Appendix F Lightning Current Appendix G Calculation of Induced Voltages and Currents in loops Appendix H Cross-section of the Entering Cable Screen Appendix J Surge Protective Device Explanation of Wording in This Code
1 General Provisions
1.0.1 This Code is formulated in order to adopt lightning protection measures by adjusting measures to local conditions for lightning protection design of structures (including construction), prevent or reduce personal injury, cultural relics and property loss arising from lightning stroke of structures, as well as damage or error operation of electrical and electronic systems triggerred by lightning electromagnetic impulse, and thereby achieving safety and reliability, advanced technology, and economy and rationality.
1.0.2 This Code is applicable to the lightning protection design of newly-built, extended and rebuilt structures.
1.0.3 For the purpose of the lightning protection design of structures, the type of lightning protection system and its layout shall be researched in detail and determined based on earnestly investigating geography, geology, soil, weather, environment conditions and lightning activity rules as well as characteristics of protected objects.
1.0.4 In addition to this Code, the lightning protection design of structures shall also comply with those specified in the current relevant standards of the state.
2 Terms
2.0.1 Lightning flash to earth
It refers to one or multiple discharges between thundercloud and ground (including overground projection).
2.0.2 Lightning stroke
It refers to one discharge in lightning flash to earth.
2.0.3 Point of strike
It refers to that point struck by lighting flash on ground or its projection. One lighting flash may have multiple points of strike.
2.0.4 Lightning current
It refers to the current flowing through the point of strike.
2.0.5 Lightning protection system (LPS)
It is used for reducing substantive damage and personal injury arising from lighting flash on structures or structure surrounding, which consists of external lightning protection system and internal lightning protection system.
2.0.6 External lightning protection system
It consists of air-termination system, down-conductor system and earth-termination system.
2.0.7 Internal lightning protection system
It consists of lightning equipotential bonding and spacing with external lightning protection system.
2.0.8 Air-termination system
It consists of air-termination pole, air-termination strip, air-termination line, air-termination net, metal roof, metal member, etc. intercepting lighting flash.
2.0.9 Down-conductor system
It refers to the conductor used for conducting lightning current from air-termination system to earth-termination system.
2.0.10 Earth-termination system
It refers to the integration of earth electrode and earthing conductor, which is used for conducting lightning current and making it flow into earth
2.0.11 Earth electrode
It refers to the conductor buried into soil or concrete foundation and used for diffusion.
2.0.12 Earthing conductor
It refers to the bonding conductor from breaking-linking card or line exchange position to earth electrode, or the bonding conductor from earthing terminal and bonding bar to earth electrode.
2.0.13 Direct lightning flash
It refers to the lighting flash generating electrical effect, heat effect and mechanical force when directly stroking to structures, other objects, ground or external lightning protection system.
2.0.14 Lightning electrostatic induction
It refers that the action of thundercloud makes nearby conductor induct electrical charge with opposite sign as thundercloud; during main discharge of thundercloud, the electrical charge in leader channel is rapidly neutralized, and the induced charge in conductor is released, if the charge is not released into ground, a very high electrical potential will be generated.
2.0.15 Lightning electromagnetic induction
It refers that the transient strong electromagnetic field is generated in the surrounding space of lightning current due to rapid change of lightning current, which makes nearby conductor induce very high electromotive force.
2.0.16 Lightning induction
It refers to lightning electrostatic induction and lightning electromagnetic induction generated on nearby conductor during lightning discharge, which may make spark discharge generate between metal components.
2.0.17 Lightning surge
It refers to transient wave due to lightning striking to lightning protection system or line and triggerred by lightning electrostatic induction or lightning electromagnetic impulse to behave as overvoltage and overcurrent.
2.0.18 Lightning surge on incoming services
It refers that the lightning wave, namely lightning surge may penetrate into rooms along these pipelines owing to the action of lightning for overhead line, cable line or metallic pipe and may endanger personal safety or equipment damage.
2.0.19 Lightning equipotential bonding (LEB)
It refers that all separated metal objects are directly connected to lightning protection system with bonding conductor via surge protective device so as to reduce the potential difference triggerred by lightning current.
2.0.20 Bonding bar
It refers to the metal strip connecting metallic device, external conductive object, power line, telecommunication line and other lines to lightning protection system so as to make equipotential bonding with lightning protection system.
2.0.21 Bonding conductor
It refers to the conductor connecting all separated conductive objects to lightning protection system.
2.0.22 Bonding network (BN)
It refers to one network composed due to interconnection of all the conductive objects of structures and internal system (excluding live conductor).
2.0.23 Earthing system
It refers to the overall system connecting bonding network and earth-termination system. 2.0.24 Lightning protection zone (LPZ)
It refers to the zone classifying the electromagnetic environment of lightning stroke; the zone interface of one lightning protection zone does not always have physical object interface, for example, not always wall, floor ceiling as zone interface.
2.0.25 Lightning electromagnetic impulse (LEMP)
It refers to electromagnetic effect generated by lightning current through resistance, inductance and capacitance coupling, including lightning surge and radiated electromagnetic field
2.0.26 Electrical system
Contents of GB 50057-2010
Contents
1 General Principles
2 Terms
3 Classification of Structures to Be Protected against Lightning
4 Protection Measures for Structures against Lightning
4. 1 Basic Requirement
4. 2 Protection Measures of The First class of Structures to be Protected against Lightning
4. 3 Protection Measures for Second Class of Structures to Be Protected against Lightning
4. 4 Lightning Protection Measures of Third Class of Structures to Be Protected against Lightning
4. 5 Other Protection Measures against Lightning
5 Lightning Protection System
5. 1 Materials for Lightning Protection System
5. 2 Air-termination System
5. 3 Down-conductor System
5. 4 Earth-termination System
6 Protection against LEMP(lightning electromagnetic impulse)
6. 1 Basic Requirement
6. 2 Lightning Pretection Zones and Protection against LEMP
6. 3 Requirements for Magnetic Shielding, Earthing and Equipotential Bonding
6. 4 Requirements for Installation and Selection of SPDS (surge protective devices)
Appendix A Expected Annual Number of Lightning Flash for Structures
Appendix B Structure Parts Suffered Easily By Lightening Stroke
Appendix C Conversion from Power Frequency Earthing Resistance to Earthing Resistance of Earth-termination System
Appendix D Determination of Protected Volume of Air-termination System with Rolling Sphere Method
Appendix E Values of Coefficient kc
Appendix F Lightning Current
Appendix G Calculation of Induced Voltages and Currents in loops
Appendix H Cross-section of the Entering Cable Screen
Appendix J Surge Protective Device
Explanation of Wording in This Code
