Fire protection system lightning protection design plan (020-87530852, Website: http://)
I. Overview
The main fire alarm and fire-fighting linkage control system (FAS) is composed of smoke detectors, temperature detectors, and analog display panels inside the building. It can automatically spray water or other fire-extinguishing liquid gas when a fire occurs. Exhaust System The general term for systems that exclude smoke from fire and prevent its spread. Normally, the object of protection of the automatic fire alarm system is classified into special grade, first grade, and second grade according to the nature of its use, fire risk, evacuation, and difficulty of extinguishing. The division of one type of building and the second type of building complies with the provisions of the current national standard "High-rise Civil Building Design Fire Protection Code" GB50045; the classification of the fire hazard of industrial plants and warehouses shall conform to the provisions of the current national standard "Fire Protection Code for Building Design" GBJ16. .
The equipments connected with the fire main unit mainly include fire alarm probes, automatic sprinklers, linkage control, 24 V DC power supply devices, fire alarm telephones, and fire alarm broadcasts. The data lines at both ends must be connected in series with the signal lightning arrester, while the audio signal lines are The audio arrester must be connected in series. The DC power supply must use a DC power arrester. Note: The fire alarm probe often transmits analog induction signals. When customizing the arrester, do not use attenuation when the signal passes through the arrester.
Second, the design basis
According to GB "Lightning Protection Technical Specifications for Building Electronic Information System" Chapter 5: Lightning Protection Design; GB 50057-94 (2000 Edition) "Building Lightning Protection Design Specification" Chapter 6: Lightning Protection Electromagnetic Pulse; Section IV, Section 6.4.1 to 6.4.12 Requirements for Surge Protectors (SPDs) in LPZ1 Area and Part V of YD/T 5098-2001 “Design Guidelines for Lightning Overvoltage Protection of Communications Bureaus (Stations)â€: Selection of SPDs; Article 5.3: SPD for signal lines; Article 5.5: Requirements for SPDs for network data lines for computers, control terminals, and monitoring systems, and IEC 61643-3 Surge Protector for low-voltage systems. Some of the "Application of SPDs in telecommunication systems" and IEC 61644-1 1997 "Standard for SPDs for Communication Systems" require that, for the protection of communication lines, 8/20μs waveforms and 5KA signal flow capacity should be used for the incoming cables of the equipment. Surge protectors limit thousands of volts of line-induced lightning overvoltage to the allowable value of the device.
Third, the implementation of measures
1. Shielding and good grounding of the wiring system of power supply and signal lines
Shielding uses various metal shields to block and attenuate electromagnetic interference or overvoltage energy applied to electronic devices. It can be divided into shielding of buildings, shielding of equipment and shielding of various cables (including pipelines). The shielding of the building can be used to connect the building reinforcement, metal framework, metal door, floor, etc. together to form a Faraday cage, and has a reliable electrical connection with the ground network to form a primary shielding network. The shielding of the equipment shall be based on the investigation of the over-voltage resistance of the electronic equipment, and the multi-level shielding shall be performed in the Lightning Protection Zone (LPZ) divided by the International Electrotechnical Commission IEC. The effectiveness of the shielding depends first and foremost on the degree of attenuation of the primary screening network, and secondly on the degree of reflection loss and absorption loss of the electromagnetic radiation from the shielding layer. Metal pipes, communication lines, and power cables for homes should be screened (using shielded cables or metal pipes) before entering the home.
2, equipotential bonding
The equipotential bonding is a part of the internal lightning protection device, the purpose of which is to reduce the potential difference caused by the lightning current. Equipotentiality is the use of connecting wires or overvoltage (surge) protectors to place the lightning protection device in the space that needs protection, the metal framework of the building, metal devices, external wires, electrical devices, telecommunication devices, etc. Equipotential bonding network to achieve equal potential equalization, to prevent fire, explosion, life hazards and equipment damage that require protection space. Room metal doors and windows, metal frame grounding, equipotential processing. Use 40×4×300mm copper bars in the fire control room to set up equipotential grounding terminal boards. All indoor racks (shells), wiring ducts, equipment protection grounding, safety protection grounding, and surge protector grounding should be Connect to the equipotential grounding terminal board. The metal frame (shell), metal trunking (or steel pipe) of the regional alarm controller, the grounding trunk in the electric shaft, the protective earthing end of the connection box, etc. should be connected to the equipotential earthing terminal board.
3, lightning protector grounding
This is a measure to diffuse lightning currents and effectively reduce the potential. There are many types of grounding, signal grounds for communication, grounds for power supply, grounds for personal protection, and logic ground for computer systems, plus grounding for lightning protection. Due to different uses, the requirements for the ground wire are also not the same. The physical requirements for lightning protection are: Once a lightning current occurs, the lightning is distributed to the earth as soon as possible. Therefore, the lower the grounding resistance of the grounding device and the shorter the connection distance between the equipotential device and the grounding device, the lower the chance that the device is damaged by lightning.
4. Installation of lightning protection devices for power supply and signal (1) Install first-level, second-level, and third-level power surge arresters in the fire control room and branch room respectively. The first model: AT PORT/4P-B100 three-phase B power arrester; the second model: AT T385/4P-C40 three-phase C power arrester; the third model: ATB140 single-phase D power arrester.
(2) Install AOTEM Aotian SPDs at the fire alarm network bus, fire alarm twisted pair, fire alarm phone line, linkage control line, and fire alarm line at each line port: AT 24 SPD and AT 110V lightning arrester. The 24V power supply SPD is installed at the DC24V power supply. How many lightning protection devices are installed on the line?
5, room grounding system
The task of the grounding device is:
ï¬ Introduce lightning currents into the earth;
ï¬ The equipotential bonding between leads;
ï¬ Potential control near conductive building walls;
ï¬ Intercept lightning currents transmitted on the ground.
(1) Grounding resistance of the grounding wire requires the grounding resistance of the equipment room: R≤1Ω.
(2) Grounding body structure The grounding body of the engine room is suitable for construction of A-type structure because it is an independent grounding device.
In the engine room, make a total collection of aluminum copper ATK008, specifications: 40mm × 4mm × 300mm, in order to ensure uniform distribution of ground potential, AC work grounding, safety protection grounding, DC grounding, lightning grounding and other four ground common grounding device. (Or in the engine room pressure belt.)
(3), grounding material grounding ground network: Requirements R ≤ 1Ω, ATK008 total busbar + lead off 35 square 500 multi-core grounding wire + grounding body.
Grounding body: It is buried in the ground and the down conductor is connected to the ground, and the lightning current is distributed to the earth. The vertical grounding body is usually composed of an AT automatic resistance-resisting grounding module 400cm×500cm×60cm and a hot-dip galvanized grounding body 50mm×50mm×5mm×L2500mm, and a horizontal grounding body is formed by connecting a 40mm×4mm hot-dip galvanized grounding body to form a ground. Ground network to meet the requirements of national lightning protection grounding resistance R ≤ 1Ω.
I. Overview
The main fire alarm and fire-fighting linkage control system (FAS) is composed of smoke detectors, temperature detectors, and analog display panels inside the building. It can automatically spray water or other fire-extinguishing liquid gas when a fire occurs. Exhaust System The general term for systems that exclude smoke from fire and prevent its spread. Normally, the object of protection of the automatic fire alarm system is classified into special grade, first grade, and second grade according to the nature of its use, fire risk, evacuation, and difficulty of extinguishing. The division of one type of building and the second type of building complies with the provisions of the current national standard "High-rise Civil Building Design Fire Protection Code" GB50045; the classification of the fire hazard of industrial plants and warehouses shall conform to the provisions of the current national standard "Fire Protection Code for Building Design" GBJ16. .
The equipments connected with the fire main unit mainly include fire alarm probes, automatic sprinklers, linkage control, 24 V DC power supply devices, fire alarm telephones, and fire alarm broadcasts. The data lines at both ends must be connected in series with the signal lightning arrester, while the audio signal lines are The audio arrester must be connected in series. The DC power supply must use a DC power arrester. Note: The fire alarm probe often transmits analog induction signals. When customizing the arrester, do not use attenuation when the signal passes through the arrester.
Second, the design basis
According to GB "Lightning Protection Technical Specifications for Building Electronic Information System" Chapter 5: Lightning Protection Design; GB 50057-94 (2000 Edition) "Building Lightning Protection Design Specification" Chapter 6: Lightning Protection Electromagnetic Pulse; Section IV, Section 6.4.1 to 6.4.12 Requirements for Surge Protectors (SPDs) in LPZ1 Area and Part V of YD/T 5098-2001 “Design Guidelines for Lightning Overvoltage Protection of Communications Bureaus (Stations)â€: Selection of SPDs; Article 5.3: SPD for signal lines; Article 5.5: Requirements for SPDs for network data lines for computers, control terminals, and monitoring systems, and IEC 61643-3 Surge Protector for low-voltage systems. Some of the "Application of SPDs in telecommunication systems" and IEC 61644-1 1997 "Standard for SPDs for Communication Systems" require that, for the protection of communication lines, 8/20μs waveforms and 5KA signal flow capacity should be used for the incoming cables of the equipment. Surge protectors limit thousands of volts of line-induced lightning overvoltage to the allowable value of the device.
Third, the implementation of measures
1. Shielding and good grounding of the wiring system of power supply and signal lines
Shielding uses various metal shields to block and attenuate electromagnetic interference or overvoltage energy applied to electronic devices. It can be divided into shielding of buildings, shielding of equipment and shielding of various cables (including pipelines). The shielding of the building can be used to connect the building reinforcement, metal framework, metal door, floor, etc. together to form a Faraday cage, and has a reliable electrical connection with the ground network to form a primary shielding network. The shielding of the equipment shall be based on the investigation of the over-voltage resistance of the electronic equipment, and the multi-level shielding shall be performed in the Lightning Protection Zone (LPZ) divided by the International Electrotechnical Commission IEC. The effectiveness of the shielding depends first and foremost on the degree of attenuation of the primary screening network, and secondly on the degree of reflection loss and absorption loss of the electromagnetic radiation from the shielding layer. Metal pipes, communication lines, and power cables for homes should be screened (using shielded cables or metal pipes) before entering the home.
2, equipotential bonding
The equipotential bonding is a part of the internal lightning protection device, the purpose of which is to reduce the potential difference caused by the lightning current. Equipotentiality is the use of connecting wires or overvoltage (surge) protectors to place the lightning protection device in the space that needs protection, the metal framework of the building, metal devices, external wires, electrical devices, telecommunication devices, etc. Equipotential bonding network to achieve equal potential equalization, to prevent fire, explosion, life hazards and equipment damage that require protection space. Room metal doors and windows, metal frame grounding, equipotential processing. Use 40×4×300mm copper bars in the fire control room to set up equipotential grounding terminal boards. All indoor racks (shells), wiring ducts, equipment protection grounding, safety protection grounding, and surge protector grounding should be Connect to the equipotential grounding terminal board. The metal frame (shell), metal trunking (or steel pipe) of the regional alarm controller, the grounding trunk in the electric shaft, the protective earthing end of the connection box, etc. should be connected to the equipotential earthing terminal board.
3, lightning protector grounding
This is a measure to diffuse lightning currents and effectively reduce the potential. There are many types of grounding, signal grounds for communication, grounds for power supply, grounds for personal protection, and logic ground for computer systems, plus grounding for lightning protection. Due to different uses, the requirements for the ground wire are also not the same. The physical requirements for lightning protection are: Once a lightning current occurs, the lightning is distributed to the earth as soon as possible. Therefore, the lower the grounding resistance of the grounding device and the shorter the connection distance between the equipotential device and the grounding device, the lower the chance that the device is damaged by lightning.
4. Installation of lightning protection devices for power supply and signal (1) Install first-level, second-level, and third-level power surge arresters in the fire control room and branch room respectively. The first model: AT PORT/4P-B100 three-phase B power arrester; the second model: AT T385/4P-C40 three-phase C power arrester; the third model: ATB140 single-phase D power arrester.
(2) Install AOTEM Aotian SPDs at the fire alarm network bus, fire alarm twisted pair, fire alarm phone line, linkage control line, and fire alarm line at each line port: AT 24 SPD and AT 110V lightning arrester. The 24V power supply SPD is installed at the DC24V power supply. How many lightning protection devices are installed on the line?
5, room grounding system
The task of the grounding device is:
ï¬ Introduce lightning currents into the earth;
ï¬ The equipotential bonding between leads;
ï¬ Potential control near conductive building walls;
ï¬ Intercept lightning currents transmitted on the ground.
(1) Grounding resistance of the grounding wire requires the grounding resistance of the equipment room: R≤1Ω.
(2) Grounding body structure The grounding body of the engine room is suitable for construction of A-type structure because it is an independent grounding device.
In the engine room, make a total collection of aluminum copper ATK008, specifications: 40mm × 4mm × 300mm, in order to ensure uniform distribution of ground potential, AC work grounding, safety protection grounding, DC grounding, lightning grounding and other four ground common grounding device. (Or in the engine room pressure belt.)
(3), grounding material grounding ground network: Requirements R ≤ 1Ω, ATK008 total busbar + lead off 35 square 500 multi-core grounding wire + grounding body.
Grounding body: It is buried in the ground and the down conductor is connected to the ground, and the lightning current is distributed to the earth. The vertical grounding body is usually composed of an AT automatic resistance-resisting grounding module 400cm×500cm×60cm and a hot-dip galvanized grounding body 50mm×50mm×5mm×L2500mm, and a horizontal grounding body is formed by connecting a 40mm×4mm hot-dip galvanized grounding body to form a ground. Ground network to meet the requirements of national lightning protection grounding resistance R ≤ 1Ω.