First, an overview of
Thunder and lightning occurred in the formation due to strong convection and cloud of thunder clouds to the ground in a strong discharge between the phenomenon of. There are natural lightning lightning directly struck by lightning, and two types of sensors. Sound and light simultaneous direct lightning strike, lightning, young and old well-known. It is with a strong current, the hot heat, violent shock waves, etc. Jihuai discharge channel of the buildings, transmission lines, hit dead wounded people, animals, etc.. The lightning sensor is quietly occurring and difficult to detect serious consequences. It is due to thundercloud electrostatic induction or discharge the role of electromagnetic induction, so that the building's metal parts, such as pipes, steel, power lines, signal transmission lines, feeders and other days out with the thunder clouds to the charge induced opposite charge, resulting in discharge Its main channel is through the power line, signal lines, Antenna, as well as to counter potential damage such as introduction of the indoor electronic equipment.
Since the lightning directly stroke and induced infringement of lightning channel is different from protective measures is different. Anti-lightning directly stroke mainly uses the lightning rod, lightning protection zone (network) and other traditional lightning devices, as long as the design specification, installation and reasonable, these lightning facilities will be able to carry out effective defense against lightning directly stroke. But no matter how perfect the lightning rod (with), the lightning sensors are powerless, because lightning is due to induction of electronic, electrical equipment, power lines, signal lines and days feeders such as luring walls have some of the system coupled with poor shielding and the lack of isoelectric Bit connection arrangements, integrated wiring unreasonable, grounding caused by non-standard back ground and so on, and thus induction lightning and thunder and lightning electromagnetic pulse is very easy to damage the invasion of the corresponding electronics and electrical equipment. A large number of electronic devices in today's information society applications, especially computer technology and the growing popularity of microwave communication technology, sensing a marked increase in damage by lightning, lightning rod lightning protection has been far from alone can not meet the electronics, communications, microelectronics and anti-lightning equipment, the actual demand.
To meet this need, in recent years also by a simple lightning rod lightning protection lightning directly stroke developed into an integrated anti-mine projects a new stage. Lightning protection engineering is a systematic project, which includes lightning directly stroke protection, and other potential connection arrangements, shielding measures, standard cabling, sensor lightning and thunder and lightning electromagnetic pulse (LEMP) protection, comprehensive and reasonable grounding and ground network system, composed of six parts. In a perfect lightning protection systems engineering (especially micro-electronics equipment, lightning protection works) are indispensable. If a part of ill-considered, not only would not achieve lightning effect, there may be cited Lei burglary and damage to the device.
Therefore, we need to prevent a direct lightning strike - a lightning rod on qualified (with) system, but also to prevent the induction by lightning - the integrated use of improved tools and installation of lightning arrester (SPD) systems, both organic combination complement each other to form a complete set of lightning protection system, which is the modern new theory of mine - an integrated lightning protection technology. Only in this way can we effectively prevent lightning accidents, reduce lightning disaster.
Many kinds of information system equipment, wiring and more asked for special treatment, the case when the operating system, in addition to outdoor exposure to various types of special income, write the antenna and other facilities, there are very focused types of electronic equipment, which we should have a direct defense lightning hazard and the need to prevent the induction lightning attacks. Therefore, the information systems of the mine should be in accordance with: "the comprehensive management of the overall defense, multiple protection layers of defenses, economical and practical, safe and reliable basic principles of comprehensive protection." The only way to effectively prevent the occurrence of lightning in order to reduce and avoid the harm caused by lightning strikes to protect the normal operation of equipment, security work carried out smoothly.
2, program design is based on the standard
GB50057-94 "Lightning Protection Code for Design of Buildings"
99D562 "Atlas of the building design and installation of lightning protection"
GB50174-93 "computer room design specification"
GB9361-88 "computer room site security requirements"
IEC61312 "Lightning electromagnetic pulse protection,"
YDJ26-89 "Communications Authority (Station) Interim technical grounding design requirements (integrated part)"
GB50169-92 "Installation earthing of electrical installations in construction and acceptance of norms"
Third, environmental analysis and mine the status quo
Factory area thunderstorm day is 34.2 years, Japan, for the mined areas. Factory has office, manufacturing plant or building more buildings at the same time has a large number of advanced electronic surveillance, security equipment. According to lightning protection standards, a comprehensive mine-awareness programs should be designed to take a comprehensive and integrated lightning protection measures. In general electronic equipment integrated lightning protection measures including building lightning directly stroke protection equipment, lightning directly stroke protection, power supply part of the mine, the signal part of the mine, mine Antenna, indoor equipment, earthing and equipotential bonding, outdoor ground network and equipotential bonding, electromagnetic shielding, as well as a variety of measures such as anti-tampering. Here according to the requirements of the construction side of the monitoring system is only designed to advance Lightning Protection Program. Therefore, this design consists mainly of lightning protection, interior equipment grounding and equipotential bonding, outdoor ground network, and several other areas.
4, the solution
The security system is divided into three areas, through the front of the camera video signal through the coaxial cable to the optical focal point, and then the signal transmitted through the fiber-optic lines to the Security Department control center, and then to video distribution. At the same time, the entire video system remote monitoring and control via local area networks. Control room is located in Zone 2. Since the whole system, the distribution of broad line is longer, are vulnerable to lightning attacks on damaged equipment, so both ends of transmission line equipment, including camera parts, sub-Optical part of the room, local area network remote access and other part is the focus of part of the lightning protection Each part of the function of lightning protection devices are required to take the power, signal lightning, grounding and other measures to ensure safety.
1, equipment, lightning directly stroke protection: Monitoring System mostly located in the room, without regard to lightning directly stroke protection; part of the camera in the outdoors, equipment installation side are installed when you set up a lightning rod here not to the design.
2, room supply mine: power supply by the total distribution room assigned to each functional unit power distribution cabinets, distribution cabinets then assigned to each room to use. As the power supply system is the focus of mine, here must be used three power protection. Among them, the total power distribution room, Taiwan's wish to install a power flow of a large Lightning connector on the power supply into the room on the first-class security protection lightning actually been installed. The allocation of power among the various functional units of all cabinets to install a power-pass flow 60KA SPD, as the power supply system of the second-level protection; in the engine room electrical distribution box or socket to take a pass at the installation of the power flow 20KA lightning protection devices, as the third-level power system protection; 3 above constitute protection, reliable protection equipment, safe use of electricity.
3, surveillance equipment, anti-lightning and the lightning invasion:
3.1 Lightning camera: camera into rotating camera and fixed cameras, each camera to the sub-Optical front room under the eaves overhead by means of routing, the shortest length of more than 30 meters, the longest 700 meters. Apart from a few cameras distributed in the outdoors, most of the distribution of indoor corridors and offices. Among them, rotate the camera to the sub-room wiring, including video coaxial cable, power lines, signal control circuit for three groups of lines, a fixed camera to the sub-room wiring, including video coaxial cable, power lines two lines. In order to ensure the camera and connect to the PDH, power supplies, signal control equipment, security equipment, in addition to the effective and reliable grounding measures, must be installed SPD protection, which focus on protection of outdoor cameras and their relative isolation connected room devices.
3.2 Sub-room and fiber optic lightning
Sub-room monitoring system as a transfer hub, multiple lines of work from the outside into the equipment using ordinary wall socket power supply, in order to ensure the safety of equipment, where the need for access lines to regulate ground, and the camera line the introduction of a set SPD protection, optical fiber into a metal stiffener must be reliably grounded. At the same time, sub-room equipment, use of 3 lightning protection power supply to prevent lightning current from the power supply line into the damaged equipment.
3.3 control center, and security part of the LAN Mine
Control room security system as a whole, the core point of the safe operation of its equipment is essential. In addition to well-grounded, the power supply, signal, outdoors directly into lines, local area network access systems must be reliable and lightning protection.
3.4 Infrared System Lightning Protection
Infrared system with power supply and signal feedback from lightning in two parts. Among them, powered in part by the Center room leads directly here in order to prevent lightning current anti-channeling, you must set the SPD to protect the signal feedback line directly into engine room alarm and other equipment in order to prevent their being struck by lightning, you must set the SPD to protect.
4, interior equipment, earthing and equipotential bonding: The company has used a lot of room electronic devices, the device itself must be well grounded, while protecting the equipment grounding lightning protection device must also be reliable. To this end, the system needs a lot of ground needs of the sub-room indoor grounding transformation, grounding and equipotential bonding. For grounding and grounding to meet the demands ¡Ü 4¦¸ the room, only the equipment and ground connections can be, for without making ground or ground does not meet the requirements and the need to re-do the local grounding system.
5, outdoor ground network: At present, main engine room outdoor ground network has been tested, the resistance value is less than 4¦¸. For the remaining non-ground room and outdoor camera, then re-do all the ground. Grounding resistance of less than 4¦¸.