1. General Provisions
1.0.1 This code is formulated with a view to preventing and reducing the damage caused by lightning on building electronic information system and protecting the safety of life and property.
1.0.2 This code is applicable to the design, construction, acceptance, maintenance and management of constructed, renovated and extended protection of building electronic information system against lightning. This code is not applicable to the protection of building electronic information system against lightning in explosive and fire hazard environments.
1.0.3 Protection of building electronic information system against lightning shall adhere to the principle of prevention and safety first.
1.0.4 In the design for protection of building electronic information system against lightning, external and internal lightning protection measures shall be coordinated according to the characteristics of building electronic information system; an overall planning shall be made according to the whole engineering requirements to achieve safety and reliability, advanced technology as well as economy and rationality.
1.0.5 Comprehensive protection combining external and internal lightning protection measures shall be adopted in the building electronic information system.
1.0.6 Corresponding protective measures shall be taken for the building electronic information system according to environmental factors, lightning activity routines, the immunity of lightning protection zone (LPZ) and system (where equipment is located) against lightning electromagnetic impulse(LEMP), extent of damage in lightning stroke accidents as well as significance of system equipment.
1.0.7 Protection of building electronic information system against lightning shall not only comply with those specified in this code but also meet the requirements of the current relevant standards of the nation.
2. Terms
2.0.1 Electronic information system
A man-machine system for the collection, processing, storage, transmission and search of information according to certain application purpose and rule, consisting of computer, communication equipment, process equipment, control equipment, electric/electronic device and its associated support equipment and facility (including network), as well as other electronic equipment.
2.0.2 Lightning protection zone (LPZ)
Specified lightning electromagnetic environment zone
2.0.3 Lightning electromagnetic impulse (LEMP)
Electromagnetic effect of lightning current
2.0.4 LEMP protection measures system (LPMS)
The entire system composed of the measures for defending lightning electromagnetic impulse
2.0.5 Synthetic lightning protection system
It refers to a generic term for the external and internal lightning protection systems. External lightning protection consists of lightning receptor, downlead and earthing device, mainly against direct lightning stroke. Internal lightning protection consists of equipotential bonding, common earthing device, shielding, reasonable wiring system, and surge protective device, etc., mainly for reducing and preventing the generation of electromagnetic effect of lightning current where protection is needed.
2.0.6 Common earthing system
It refers to an earthing system which is made by connecting the lightning protection system earthing device, building hardware, low-voltage distribution protection wire, equipotential bonding terminal board or bonding bar, equipment protective earthing, shield earthing, electrostatic earthing, and functional earthing, etc.
2.0.7 Natural earthing electrode
A general term for hardware, metal well casing and steel bar in concrete which also have earthing function, but are not arranged specially for this purpose.
2.0.8 Earthing terminal
A terminal or earthing bar which connects protective conductor, equipotential bonding conductor, working earthing conductor and earthing device
2.0.9 Main equipotential earthing terminal board
Metal board connecting multiple earthing terminals that is directly connected with the earthing device
2.0.10 Floor equipotential earthing terminal board
Earthing terminal board which is arranged on the floor of building for the equipotential bonding of local equipotential earthing terminal board
2.0.11 Local equipotential earthing terminal board
Terminal board arranged in the equipment room of electronic information system for local equipotential bonding network earthing.
2.0.12 Equipotential bonding
Measures for directly connecting separated metal parts, external conductors, power lines, communication lines and other cables with bonding conductors or surge protective device so as to reduce the potential difference caused by lightning current among them.
2.0.13 Equipotential bonding bar
Metal conductor used for equipotential bonding.
2.0.14 Equipotential bonding network
A network composed of all the conductors and surge protective devices as equipotential bonding in the building.
2.0.15 Electromagnetic shielding
A measure to reduce the penetration of alternating electromagnetic field into a designated zone through conducting material.
2.0.16 Surge protective device (SPD)
It, also called surge protector, is the electrical device used to restrict transient overvoltage and discharge surge current, which at least contains one nonlinear element.
2.0.17 Voltage switching type SPD
Such SPD takes on high impedance in the absence of surge, but it abruptly change to low impedance in the presence of voltage surge. Generally, discharge gap, gas discharge tube, thyristor and triode ac switch are adopted as the assemblies of such SPD.
2.0.18 Voltage limiting type SPD
Such surge protective device, also called voltage-clamping-type SPD, takes on high impedance in the absence of surge, but it will continuously reduce the impedance along with increase of surge current and voltage. Common apparatus used as this type of nonlinear device are piezoresistor and suppression diode.
2.0.19 Nominal discharge current (In)
The peak current with 8/20μs waveform flowing through SPD, to be used in SPD Class II test as well as Classes I and II pretreatment test
2.0.20 Maximum discharge current (Imax)
The peak current with 8/20μs waveform flowing through SPD, to be determined according to Class II operating duty test procedures. Imax is greater than In.
2.0.21 Impulse current (Iimp)
The current defined by such three parameters as peak current (Ipeak), quantity of electric charge (Q) and specific energy (W/R), to be used in Class I test of SPD, for which the typical waveform is 10/350μs.
2.0.22 Maximum continuous operating voltage (Uc)
Effective value of maximum AC voltage or DC voltage that can be continuously applied to the SPD
2.0.23 Residual voltage (Ures)
The peak value of voltage that appears between the terminals of an SPD due to the passage of discharge current
2.0.24 Measured limiting voltage
The maximum peak value of voltage that is measured across the wiring terminals of the SPD during the application of impulses of specified waveform and amplitude
2.0.25 Voltage protection level (Up)
The performance parameters representing the voltage between limited wiring terminals of SPD, which shall be greater than the maximum value of limited voltage
2.0.26 Effective protection level (Up/f)
The sum of inductive drop of SPD connecting wire and SPD voltage protection level
2.0.27 1.2/50μs voltage impulse
The impulse voltage with 1.2 μs virtual front time and 50μs semi-peak time
2.0.28 8/20μs current impulse
The impulse current with 8μs virtual front time and 20μs semi-peak time
2.0.29 Combination wave
Combination wave is generated by surge generator that outputs 1.2/50μs impulse voltage in the case of open circuit and outputs 8/20μs impulse current in the case of short circuit. Amplitude and waveform of the voltage and current supplied to the SPD shall be determined by the impedance of surge generator and SPD subject to the impact effect. The ratio of peak value if open-circuit voltage to that of short-circuit current is 2 Ω, which is defined as virtual output impedance Zf. Short-circuit current is expressed as Symbol Isc and open-circuit voltage is expressed as Symbol Uoc.
2.0.30 Class I test
It refers to the test carried out according to the nominal discharge current (In) defined in 2.0.19 of this code, the 1.2/50μs impulse voltage defined in 2.0.27 and the impulse current (Iimp) defined in 2.0.21.Class I test may also be expressed as T1 encircled with a block, namely .
2.0.31 Class II test
It refers to the test carried out according to the nominal discharge current (In) defined in 2.0.19 of this code, the 1.2/50μs impulse voltage defined in 2.0.27 and the maximum discharge current (Imax) defined in 2.0.20.Class II test may also be expressed as T2 encircled with a block, namely .
2.0.32 Class III test
It refers to the test carried out according to the combination wave defined in 2.0.29 of this code. Class III test may also be expressed as T3 encircled with a block, namely .
2.0.33 Insertion loss
The loss caused by a SPD inserted into the transmission system, which is equal to the ratio of the power before insertion to that after insertion. Insertion loss is usually expressed as decibel (dB).
2.0.34 Degradation
Variance in original performance parameters of SPD caused by the impacts of surge, application or adverse environment
2.0.35 Exothermic welding
The connection method by virtue of fast generation of ultrahigh heat during exothermic chemical reaction to smelt two conductors into one conductor
2.0.36 Risk of lightning damage (R)
The ratio of the annual average potential damage (person and object) caused by lightning to the total value (person and object) of the protected object
3. Division of Lightning Protection Zone
3.1 Classification of Regional Thunderstorm Day
3.1.1 Regional thunderstorm days shall be classified according to the average annual thunderstorm days.
3.1.2 Regional thunderstorm days shall be subject to the local average annual thunderstorm days published by the nation.
3.1.3 According to the average annual thunderstorm days, the lightning zone shall be divided into less lightning zone, middle lightning zone, more lightning zone and strong lightning zone upon classes of regional thunderstorm days:
1 Less lightning zone: average annual thunderstorm days of 25d or less;
2 Middle lightning zone: average annual thunderstorm days more than 25d and less than or equal to 40d;
3 More lightning zone: average annual thunderstorm days more than 40d and less than or equal to 90d;
4 Strong lightning zone: average annual thunderstorm days more than 90d.
3.2 Division of Lightning Protection Zone
3.2.1 Different lightning protection zones shall be divided for the buildings requiring protection and control of the LEMP environment according to the requirements of 3.2.2 of this code.
3.2.2 Lightning protection zone shall meet the following requirements:
1 Zone LPZ0A: the zone threatened by direct lighting strike and all lightning electromagnetic fields. The internal system of this zone may be subject to the impact of either the whole or the part of lightning surge current;
2 Zone LPZ0B: the zone protected against direct lighting strike and threatened by all lightning electromagnetic fields. The internal system of this zone may be subject to the impact of part of lightning surge current;
3 Zone LPZ1: the zone where the surge current is limited due to the current shunting at the boundary and the action of SPD;
4 LPZ2~n follow-up lightning protection zones: the zones where the surge current is further limited due to the current shunting at the boundary and the action of SPD. The space shielding in these zones may further attenuate the lightning electromagnetic fields.
3.2.3 The protected objects shall be placed in the lightning protection zones that the electromagnetic properties are compatible with the tolerance capacities of such objects.
1. General Provisions
2. Terms
3. Division of Lightning Protection Zone
3.1 Classification of Regional Thunderstorm Day
3.2 Division of Lightning Protection Zone
4. Classification of Lightning Protection Level and Risk Assessment
4.1 General Requirements
4.2 Determine Lightning Protection Level by Efficiency of LPS
4.3 Determine Lightning Protection Level by the Importance, the Application and the Value of building Electronic Information System
4.4 Risk assessment Based on Risk Management
5. Lightning Protection Design
5.1 General Requirements
5.2 The Equipotential Bonding and the Common Earthing System
5.3 Shielding and Line Routing
5.4 Selection of SPD
5.5 Lightning Protection and Earthing of Electronic Information Systems
6. Lightning Protection Construction
6.1 General Requirements
6.2 Earthing-termination System
6.3 Earthing Conductor
6.4 Equipotential Earthing Terminal Board (Equipotential Bonding Bar)
6.5 Surge Protective Device
6.6 Cable Laying
7. Inspection and Acceptance
7.1 Inspection
7.2 Items for Acceptance
7.3 Final Acceptance
8. Maintenance and Management
8.1 Maintenance
8.2 Management
Appendix A Calculating Method for N and NC for the Lightning Risk Assessment of Building Electronic Information System
Appendix B Risk Assessment Based on Risk Management
Appendix C Lightning Current Parameters
Appendix D Calculation of Lightning Magnetic Strength
Appendix E Test Waveforms and Parameters of Signal SPD
Appendix F The Statistics Table of Average Annual Thunderstorm Days for Main Cities in China
Explanation of Wording in This Standard
List of Quoted Standards
