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GB/T 21714.4-2015: Protection against lightning -- Part 4: Electrical and electronic systems within structures
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Basic data | Standard ID | GB/T 21714.4-2015 (GB/T21714.4-2015) | | Description (Translated English) | Protection against lightning -- Part 4: Electrical and electronic systems within structures | | Sector / Industry | National Standard (Recommended) | | Classification of Chinese Standard | K09 | | Classification of International Standard | 13.260 | | Word Count Estimation | 71,721 | | Date of Issue | 2015-09-11 | | Date of Implementation | 2016-04-01 | | Older Standard (superseded by this standard) | GB/T 21714.4-2008 | | Quoted Standard | GB 16895.22-2004; GB/T 16935.1-2008; GB/T 17626.5-2008; GB/T 17626.9-2011; GB/T 17626.10-1998; GB/T 18802.12-2014; GB/T 21714.1-2015; GB/T 21714.2-2015; GB/T 21714.3-2015; GB 18802.1-2011; GB/T 18802.21-2004; GB/T 18802.22-2008 | | Adopted Standard | IEC 62305-4-2010, IDT | | Regulation (derived from) | National Standard Announcement 2015 No.25 | | Issuing agency(ies) | General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China, Standardization Administration of the People's Republic of China | | Summary | This standard specifies the risk in the building of electrical and electronic systems of lightning electromagnetic pulse protection measures (SPM) the design, installation, inspection, maintenance and testing of materials, to reduce the lightning electromagnetic pulse (LEMP) make it a permanent failure. This standard does not contain an internal system failure may result in lightning protection electromagnetic interference. But Appendix A profile can also be used to evaluate such harassment. Electromagnetic interference protection measures refer to IEC 60364-4-44 and IEC 61000. This standard can guide cooperation between designers and electrical and electronic systems designer protective measures in order to achieve the best protective effect. This standard does not address in detail the design of electrical and electronic systems themselves. | GB/T 21714.4-2015: Protection against lightning -- Part 4: Electrical and electronic systems within structures
---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.
Protection against lightning - Part 4. Electrical and electronic systems within structures
ICS 13.260
K09
National Standards of People's Republic of China
Replace GB/T 21714.4-2008
Lightning protection
Part 4. Electrical and electronic systems in buildings
Protectionagainstlightning-Part 4.Electricalandelectronicsystems
(IEC 62305-4.2010, IDT)
Released on.2015-09-11
2016-04-01 implementation
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
China National Standardization Administration issued
Content
Foreword V
Introduction VI
1 Scope 1
2 Normative references 1
3 Terms and Definitions 2
4 SPM design and installation 4
4.1 General requirements 4
4.2 SPM Design 8
4.3 Lightning Protection Zone (LPZ) 8
4.4 Basic SPM 11
5 Grounding and connection network 12
5.1 General requirements 12
5.2 Grounding device 12
5.3 Connecting to the network 13
5.4 Connection row 17
5.5 Grounding at the LPZ boundary 17
5.6 Materials and dimensions of connecting parts 18
6 Magnetic Shielding and Wiring 18
6.1 General requirements 18
6.2 Space Shield 19
6.3 Internal Line Shield 19
6.4 Internal Line Wiring 19
6.5 External line shielding 19
6.6 Magnetic shielding materials and dimensions 19
7 SPD System 19
8 isolation interface 20
9 SPM Management 20
9.1 General requirements 20
9.2 SPM Management Plan 20
9.3 SPM inspection 21
9.4 Maintenance 22
Appendix A (informative) Fundamentals of Electromagnetic Environment Assessment in the LPZ Area 23
Appendix B (informative) Implementation of SPM in existing buildings 42
Appendix C (informative) Selection and installation of SPD systems 55
Appendix D (informative) SPD selection factors to consider 60
References 64
Figure 1 Basic principles for dividing different LPZs
Figure 2 SPM (LEMP Protection Measures) Example 6
Figure 3 Example of lightning protection zone interconnection 9
Figure 4 Example of extended lightning protection zone 10
Figure 5 Example of a connection between a network and a grounding device to form a three-dimensional grounding system
Figure 6 Factory grid grounding device 13
Figure 7 Equipotential bonding using building reinforcements 14
Figure 8 Equipotential bonding within a steel structure building 15
Figure 9 Conductive components of the internal system access to the connection network 16
Figure 10 Combination of internal system conductive components into the connection network 17
Figure A.1 LEMP condition resulting from lightning strikes 24
Figure A.2 Simulating the rising edge of the magnetic field with a damped oscillation 26
Figure A.3 Large space shield with steel and metal frame 27
Figure A.4 Space for installation of electrical and electronic systems in LPZn 28
Figure A.5 Using line wiring and line shielding measures to reduce the inductive effect 29
Figure A.6 Office Building SPM Example 30
Figure A.7 Estimation of the value of the magnetic field in direct lightning strikes 31
Figure A.8 Estimation of the value of the magnetic field in the vicinity of a lightning strike 33
Figure A.9 Distance sa depends on the radius of the ball and the size of the building 35
Figure A.10 Type of grille type large space shield 36
Figure A.11 Magnetic field strength inside the Type 1 grid type shield H1/MAX 37
Figure A.12 Magnetic field strength H1/MAX 37 in a Type 1 grid shield
Figure A.13 Low current level test for shielding internal magnetic field estimates in buildings 38
Figure A.14 Induced voltage and current in the line loop 39
Figure B.1 Existing building SPM design steps 44
Figure B.2 Possibility of establishing a lightning protection zone LPZ in an existing building 45
Figure B.3 Place the shielded cable close to the plate to reduce the loop area 49
Figure B.4 Example of additional shielding with a metal plate 49
Figure B.5 Protection of antennas and other external equipment 50
Figure B.6 Intrinsic shielding provided by work escalators and piping 51
Figure B.7 Ideal laying position for the antenna tower cable (steel lattice antenna tower cross section) 51
Figure B.8 SPM upgrade of existing buildings 53
Figure C.1 Surge voltage between the live conductor and the connection bar 57
Figure D.1 Example SPD setup for Class I, II, and III tests 61
Figure D.2 Basic examples of lightning damage distribution in different sources and systems in buildings 61
Figure D.3 Basic example of average current distribution 62
Table 1 Minimum cross-sectional area of the connecting parts 18
Table 2 SPM Management Plan for New Buildings and Existing Buildings Changing Structure and Use 21
Table A.1 Damage source and equipment related parameters 24
Table A.2 Example 32 for I0/MAX=100kA and wm=2m
Table A.3 Grid-type spatial shielding attenuation of plane wave magnetic field 33
Table A.4 Ball radius 35 when the maximum lightning current is 35
Table A.5 Example 35 for I0/MAX=100kA and wm=2m and corresponding SF=12.6dB
Table B.1 Characteristics of the building and its surroundings 42
Table B.2 Installation Characteristics 43
Table B.3 Equipment characteristics 43
Table B.4 Other issues to be considered in the concept of protection 43
Table D.1 Preferred value of Iimp 60
Foreword
GB/T 21714 "Lightning Protection" consists of the following four parts.
--- Part 1. General;
--- Part 2. Risk Management;
--- Part 3. Physical damage and life-threatening of buildings;
--- Part 4. Electrical and electronic systems in buildings.
This part is the fourth part of GB/T 21714.
This part replaces GB/T 21714.4-2008 "Lightning Protection Part 4. Electrical and Electronic Systems in Buildings", and GB/T 21714-
Compared with.2008, the main technical changes are as follows.
--- Increased isolation interfaces that reduce conducted surges entering the building's lines (see 3.24, 4.4, Chapter 8, B.10, B.15.3);
--- Modified the minimum cross-sectional area of the connecting parts (see Table 1);
--- The calculation of the electromagnetic damage source of the internal system increases the first negative pulse current (see A.4);
--- Considering the oscillation and induction phenomena on the SPD downstream line, the SPD voltage protection level has been improved (see C.2.1);
--- Appendix C removed the content of coordination with SPD;
--- Appendix D gives new considerations for SPD selection.
This section uses the translation method equivalent to IEC 62305-4.2010 "Lightning Protection Part 4. Electrical and Electronic Systems in Buildings".
The documents of our country that have a consistent correspondence with the international documents referenced in this part are as follows.
--- GB 18802.1-2011 Low-voltage surge protectors (SPD) Part 1. s.
Requirements and test methods (IEC 61643-1.2005, MOD)
--- GB/T 18802.21-2004 Low voltage surge protectors - Part 21. Surge protectors for telecommunication and signal networks
(SPD)---Performance requirements and test methods (IEC 61643-21.2000, IDT)
--- GB/T 18802.22-2008 Surge protectors (SPD) for low-voltage distribution systems - Part 22. Telecommunications and signal networks
Surge Protector (SPD) Selection and Use Guidelines (IEC 61643-22.2004, IDT)
Please note that some of the contents of this document may involve patents, and the issuing organization of this document is not responsible for identifying these patents.
This part is proposed and managed by the National Lightning Protection Standardization Technical Committee (SAC/TC258).
This section is responsible for drafting unit. Tianjin Zhongli Lightning Protection Technology Co., Ltd.
Participated in the drafting of this section. Sichuan Zhongguang Lightning Protection Technology Co., Ltd., Beijing Lightning Protection Equipment Safety Testing Center, Industry and Letter
Communication and Measurement Center of the Ministry of Information, Shanghai Dianke Electric Technology Co., Ltd., Shenzhen Lightning Protection Center, Zhejiang Leitai Electric Co., Ltd., Hunan Province
Lei Center, Schneider Electric (China) Co., Ltd., Xiamen Daheng Technology Co., Ltd., Anhui Jinli Electric Technology Co., Ltd.
The main drafters of this section. Sun Wei, Xue Wen'an, Wang Deyan, Yang Guohua, Guan Xiangshi, Song Pingjian, Li Rujian, Zhou Wei, Gao Bo, Tang Xiaofeng,
Yu Liping, Sun Danbo, Li Hongbin, Cai Zhenxin, Wang Zhigang, Wang Daoping, Hou Zheng, Li Xin, Zeng Rui, Wang Fei.
The previous versions of this section were released as follows.
---GB/T 21714.4-2008.
Introduction
As a source of damage, lightning is a high-energy phenomenon. Lightning releases hundreds of megajoules of energy, in electrical and electronic systems within buildings
Compared to the energy of the order of millijoules that sensitive electronic devices can withstand, it is undoubtedly necessary to add protective measures to protect these devices.
This standard is required due to the increasing economic losses caused by the failure of electrical and electronic systems due to lightning electromagnetic effects. One of the most
Important electronic systems for data processing and storage, as well as for high-investment, large-scale, high-complexity plants (for cost and
Safety factors, these factories do not allow production interruptions) of the process control and safety of the electronic system.
As specified in GB/T 21714.1, lightning can cause different types of hazards in buildings.
D1 damage to life due to electric shock;
D2 Physical damage such as fire, explosion, mechanical damage and chemical leakage caused by lightning current, including sparks;
D3 Internal system failure due to lightning electromagnetic pulse.
GB/T 21714.3 describes protective measures to reduce the risk of physical damage and life injury, but does not include electrical and electronic systems.
Protection.
Therefore, this part of GB/T 21714 provides protection against the risk of permanent failure of electrical and electronic systems in buildings.
data.
Lightning Electromagnetic Pulse (LEMP) can cause permanent failure of electrical and electronic systems by.
a) conducted and induced surges transmitted to the equipment by connecting wires;
b) The effect of the radiated electromagnetic field acting directly on the device.
Surge can occur outside or inside the building.
--- The external surge of the building is generated by the lightning strike home line or the ground near it, and transmitted to the electrical and electronic systems via the line;
--- The surge inside the building is generated by lightning strikes on or near the building.
Note 1. Surge can also be generated by switching the switch inside the building, such as the disconnection of the inductive load.
The generation of lightning electromagnetic coupling can be based on different mechanisms.
--- Resistive coupling (such as the grounding resistance of the building grounding device or the cable shielding resistance);
--- Magnetic field coupling (eg due to the loop formed by the lines in the electrical and electronic systems or the inductance of the connecting conductor);
--- Electric field coupling (eg due to whip antenna reception).
Note 2. The electric field coupling is much smaller than the magnetic field coupling and can be ignored.
Radiated electromagnetic fields can be generated in the following ways.
---The lightning current flows through the lightning channel;
--- part of the lightning current flowing through the conductor (such as the external LPS down conductor described in GB/T 21714.3, or as described in this section)
Lightning current in the external space shield).
Lightning protection
Part 4. Electrical and electronic systems in buildings
1 Scope
This part of GB/T 21714 provides for the installation of lightning electromagnetic pulse protection (SPM) for electrical and electronic systems in buildings.
Data for metering, installation, inspection, maintenance, and testing to reduce the risk of permanent failure of Lightning Electromagnetic Pulse (LEMP).
This section does not cover the protection against lightning electromagnetic interference that may cause internal system failure. However, the information in Appendix A can also be used for evaluation.
This harassment. For EMI countermeasures, see IEC 60364-4-44 [1] and IEC 61000 [2].
This section guides the collaboration between electrical and electronic system designers and the designer of the protective measures to achieve the best protection.
This section does not cover the detailed design of the electrical and electronic systems themselves.
2 Normative references
The following documents are indispensable for the application of this document. For dated references, only dated versions apply to this article.
Pieces. For undated references, the latest edition (including all amendments) applies to this document.
GB 16895.22-2004 Electrical installations of buildings - Part 5-53. Selection and installation isolation, switching and control of electrical equipment
Equipment Section 534. Overvoltage Protection Appliances (IEC 60364-5-53.2001, IDT)
GB/T 16935.1-2008 Insulation of equipment in low-voltage systems - Part 1. Principles, requirements and tests (IEC 60664-1.
2007, IDT)
GB/T 17626.5-2008 Electromagnetic compatibility test and measurement technology Surge (impact) immunity test (IEC 61000-4-5.
2005, IDT)
GB/T 17626.9-2011 Electromagnetic compatibility test and measurement technology Pulse magnetic field immunity test (IEC 61000-4-9.2001,
IDT)
GB/T 17626.10-1998 Electromagnetic compatibility test and measurement technique - Damping oscillating magnetic field immunity test (IEC 61000-4-
10.1993, IDT)
GB/T 18802.12-2014 Low voltage surge protectors (SPD) Part 12. Surge protector selection for low-voltage distribution systems
And guidelines for use (IEC 61643-12.2008, IDT)
GB/T 21714.1-2015 Lightning protection - Part 1. General (IEC 62305-1.2010, IDT)
GB/T 21714.2-2015 Lightning protection Part 2. Risk management (IEC 62305-2.2010, IDT)
GB/T 21714.3-2015 Lightning protection - Part 3. Physical and structural hazards of buildings (IEC 62305-3.2010,
IDT)
Low voltage surge protectors (SPD) Part 1 . Performance requirements for surge protectors for low-voltage distribution systems
And test methods (Low-voltagesurgeprotectivedevices-Part 1. Surgeprotectivedevicesconnectedtolow-
voltagepowerdistributionsystems-Requirementsandtests)
IEC 61643-21 Low-voltage surge protectors (SPD) Part 21. Surge protector (SPD) performance for telecommunications and signal networks
Requirements and test methods (Lowvoltagesurgeprotectivedevices-Part 21. Surgeprotectivedevicesconnectedto
telecommunicationsandsignalingnetworks-Performancerequirementsandtestingmethods)
Surge protectors (SPD) for low-voltage distribution systems - Part 22. Surge protectors for telecommunication and signal networks
(SPD) Selection and Usage Guidelines (Low-voltagesurgeprotectivedevices-Part 22. Surgeprotectivedevices
Connectedtotelecommunicationsandsignalingnetworks-Selectionandapplicationprinciples
3 Terms and definitions
The following terms and definitions as defined elsewhere in GB/T 21714 apply to this document.
3.1
Electrical system electricalsystem
A system consisting of low voltage power supply components.
3.2
Electronic system
Systems containing sensitive electronic components such as communication devices, computers, control and instrumentation systems, radio systems, power electronics.
3.3
Internal system internalsystem
Electrical and electronic systems within the building.
3.4
Lightning protection lightningprotection; LP
The entire system used for lightning protection of buildings, including their internal systems, objects, and people, typically including LPS and SPM.
3.5
Lightning protection device lightningprotectionsystem;LPS
The entire system used to reduce the physical damage caused by lightning strikes on buildings.
Note. LPS consists of two parts, the external and internal lightning protection system.
3.6
Lightning electromagnetic pulse lightningelectromagneticimpulse; LEMP
All electromagnetic effects of lightning currents coupled through electrical resistance, inductance and capacitance, including surges and radiated electromagnetic fields.
3.7
Surge surge
A transient that occurs in the form of overvoltage and/or overcurrent caused by LEMP.
Note. Surge is also called power surge. 1)
1) Editor's Note.
3.8
Impact voltage rating ratedimpulsewithstandvoltagelevel
Uw
The impulse withstand voltage specified by the manufacturer for the equipment or its components is used to characterize its ability to withstand overvoltage.
Note. This section only considers the withstand voltage between the live conductor and ground (see GB/T 16935.1-2007, definition 3.9.2).
3.9
Lightning protection level lightningprotectionlevel; LPL
The ordinal number associated with a set of lightning current parameter values, the probability that the set of parameters does not exceed the maximum and minimum design values when lightning occurs in nature
related.
Note. The lightning protection level is used to design lightning protection measures based on a set of related parameter values of lightning current.
3.10
Lightning protection zone lightningprotectionzone; LPZ
The area where the lightning electromagnetic environment is specified.
Note. The area boundaries of lightning protection zones are not necessarily physical boundaries (such as walls, floors, ceilings, etc.).
3.11
LEMP protection measures LEMPprotectionmeasures
SPM
Measures to protect the LEMP effect from internal systems.
Note 1. SPM is part of integrated lightning protection.
Note 2. The term in the draft of the third edition of IEC 62305.1 is modified to SurgeProtectionMeasures. 2)
3.12
Grille type space shield grid-likespatialshield
Magnetic shielding with opening features.
Note. For buildings or rooms, it is suitable to use the natural metal components of the building to connect with each other (such as steel bars, metal frames and metal branches in concrete).
Support, etc.).
3.13
Grounding device earthterminationsystem
A component of the external LPS that conducts and distributes lightning currents into the earth.
3.14
Connection network bondingnetwork
A network in which all metal components of a building and internal conductors (except live conductors) are interconnected.
Note. "Connected network", also known as "lapped network", is a network formed by low-impedance electrical connections in order to avoid dangerous potential differences. 3)
3.15
Grounding system earthingsystem
A complete system consisting of a grounding device and a connected network.
3.16
Surge protector surgeprotectivedevice; SPD
A device used to limit transient overvoltages and shunt inrush currents, which contain at least one nonlinear component.
Note. Surge protectors are also known as surge protectors, lightning protectors, lightning protection devices, lightning arresters, etc. 4)
2) Editor's Note.
3) Editor's Note.
4) Editor's Note.
3.17
SPD SPDtestedwithIimp tested with Iimp
A SPD that withstands a partial lightning current of a typical waveform of 10/350 μs requires a corresponding impulse test current Iimp.
Note. For power supply lines, the appropriate test current Iimp is defined by the Class I test procedure of IEC 61643-1.2005.
3.18
SPD SPDtestedwithIn tested with In
A SPD that withstands an induced surge current of a typical waveform of 8/20 μs requires a corresponding impulse test current In.
Note. For the supply line, the appropriate test current In is defined by the Class II test procedure of IEC 61643-1.2005.
3.19
SPD SPDtestedwithacombinationwave with combined wave test
The SPD that withstands the induced surge current of a typical waveform of 8/20 μs requires a corresponding impact test current ISC.
Note. For power supply lines, the appropriate combined wave test is defined by the Class III test procedure of IEC 61643-1.2005, specifying a combined wave generator with an internal resistance of 2 Ω.
The open circuit voltage Uoc has a waveform of 1.2/50 μs, a short-circuit current of Isc, and a waveform of 8/20 μs.
3.20
Voltage Switch Type SPD voltage-switchingtypeSPD
It has a high impedance when there is no surge, but once it responds to a voltage surge, its impedance suddenly changes to a low SPD.
Note 1. Common devices used as voltage switching devices are. discharge gap, gas discharge tube (GDT), thyristor (silicon controlled rectifier), bidirectional triode thyristor.
This SPD is sometimes referred to as "short-circuit type SPD".
Note 2. Voltage switching devices have discontinuous voltage/current characteristics.
3.21
Pressure limiting SPD voltage-limitingtype SPD
High impedance without surge, but as the surge current and surge voltage increase, its impedance will continue to decrease in SPD.
Note 1. Some common components used as nonlinear devices are. varistors and suppression diodes. These SPDs are sometimes referred to as "clamped SPDs."
Note 2. The voltage limiting device has continuous voltage/current characteristics.
3.22
Combined SPD combination SPDtype
The SPD that assembles the voltage switch type component and the voltage limiting type component, according to the characteristics of the applied voltage, the SPD shows the voltage switch
Characteristics or voltage limiting characteristics, or both voltage switching characteristics and finite pressure characteristics.
3.23
Coordinated SPD system coordinatedSPDsystem
In order to reduce the failure of electrical and electronic systems, a set of SPDs that make up the system are properly selected, matched and installed.
3.24
Isolation interface isolatinginterfaces
A device capable of reducing or isolating conducted surges on the line entering the LPZ.
Note 1. Isolation transformers, metal-free cables and optical isolators including grounding of the inter-winding shield.
Note 2. The insulation resistance characteristics of these devices themselves or by the addition of SPD are suitable for such applications.
4 SPM design and installation
4.1 General requirements
Lightning Electromagnetic Pulse (LEMP) can jeopardize electrical and electronic systems, so SPM should be used to avoid system failures inside the building.
SPM design should be done by lightning and surge protection professionals who have extensive electromagnetic compatibility (EMC) knowledge
Knowledge and installation experience.
The protection of LEMP is based on the concept of Lightning Protection Zone (LPZ). the space containing the protected system can be divided into several LPZs. This
These areas are part of a theoretically specified space (or internal system), the severity of LEMP in a space and the internal systems of that space
The tolerance levels match (see Figure 1). Successive regions are divided according to significant changes in LEMP intensity. The perimeter of the LPZ is protected by the protection
Measures are defined (see Figure 2).
Home-to-house public facilities for equipotential bonding directly or via SPD
Note. This figure is an example of a building partitioning internal LPZ. All metal utilities entering the building are connected to the LPZ1 boundary for isoelectric purposes.
Bitwise connection. At the same time, metal utilities entering the LPZ2 (eg, computer room) are connected to the LPZ2 boundary for equipotential bonding.
Figure 1 Basic principles for dividing different LPZs
Figure 2 SPM (LEMP protection measures) example
But there is no protection against the radiated magnetic field (H0)
Shield boundary
Unshielded boundary
Note 1. The SPD can be located in the following locations.
--- The boundary of LPZ0/1 (for example, on the main switchboard MB);
--- the boundary of LPZ1/2 (for example, in the distribution panel SB);
--- Or close to the device (for example, at the power outlet SA).
Note 2. Refer to GB 16895.22-2004 for detailed installation rules.
Figure 2 (continued)
LEMPs that permanently disable electrical and electronic equipment can be generated by the following factors.
--- Conduction and induced surges transmitted to the device through connecting wires;
--- The effect of the radiated electromagnetic field acting directly on the device.
For...
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