Security equipment how to mine?

From late July to early August, the summer thunderstorms frequently occur. In recent lightning disasters, more than 80% of internal lightning, including electrical appliances, monitoring systems, probes, etc., have been damaged, and some high-tech electronic equipment has the ability to resist interference. Weak, favorite "injured" in the thunderstorm days, such as the monitoring probes, intercom systems and other facilities in the residential area there is no lightning protection device, the induction of lightning is easy to take advantage of, and destroy the system. In fact, these high-tech electronic systems must have special protections, such as installing electromagnetic shielding devices and overvoltage protection devices that prevent lightning electromagnetic pulses and internal operating overvoltages from damaging electronic devices.

Security equipment how to mine?

Modern security monitoring products are all microelectronic products. Monitoring equipment has features such as high density, high speed, low voltage, and low power consumption. It is very sensitive to various electromagnetic disturbances such as lightning overvoltage, power system operation overvoltage, electrostatic discharge, electromagnetic radiation, etc., which makes the monitoring system equipment vulnerable to lightning / overvoltage damage, the consequences of which may cause the entire monitoring system to run Failure, and cause unpredictable economic losses and safety risks. The entire system is widely distributed and has long lines. It is vulnerable to lightning strikes and damages the equipment. Therefore, the equipment at both ends of the transmission line, including the camera part, the optical part of the branch room, and remote access to the LAN, is a key part of lightning protection. Each part Functional devices must adopt measures such as power supply lightning protection, signal lightning protection, and grounding to ensure safety. FAQs for installing lightning protection equipment in monitoring systems?

One, grounding resistance is too large or no grounding. The grounding resistance of the lightning protection system of the monitoring system is not clearly defined in the "Engineering Design Specification for Video Security Monitoring System" and "Technical Specifications for Lightning Protection in Building Information Systems." Generally, the grounding resistance of the design monitoring system is designed according to the resistance value of the computer room and the grounding resistance of the information system: the independent grounding is not greater than 4 ohms, and the joint grounding resistance is not greater than 1 ohm. Specifically speaking, the more different geological conditions can appropriately increase the grounding resistance of the monitoring system. For example, the forest fire protection unit must be installed on the ridge. The address is bluestone, there is no river ditches within 200 meters, and no excavation is possible. Large gravel, soil zone. At this time, if the ground of the monitoring system in this particular place is required to be no more than 4 ohms, and the cost is ten times or even several ten times of the monitoring system itself, then the appropriate increase in the grounding resistance should be selected, and the cable with the large flow rate should be used as the connection. Ground line.

Second, no direct lightning protection measures, this situation is more common is the camera, some people believe that the three-in-one signal lightning arrester has been installed, grounding [industrial electrical network -cnelc] is also done, there should be no problem, but However, it is not known that the arrester is a tool for lightning protection and lightning induction, and it has no effect on direct lightning. Lightning damage to the electronic information system generally has several means: 1. Mechanical effects, such as a lightning strike on a tree, sometimes knock off the support of a big tree, mainly relying on the mechanical effect of a lightning strike. 2, thermal effects, the instantaneous temperature of the lightning strike point can reach more than 3,000 degrees, so that the metal instant. 3, electromagnetic effect, this is an invisible killer, it has contributed to the instantaneous high current electromagnetic induction equipment burned out. As long as the lightning protection is made by relying on lightning rods, the direction of operation of the lightning is changed, making it impossible for lightning to hit directly. There is also a situation in which a lightning rod is installed on a curved ball machine. In this case, the metal rod itself will protect the dome, and there is no need to increase the cost and install the lightning rod.

Third, the signal arrester is too far away from the equipment to be protected. If the arrester is installed too far away from the device, there is no way to eliminate the lightning currents induced on the communication lines and power lines after the arrester reaches the front of the device. Therefore, it is recommended that the signal lightning arrester should be installed directly to the front end of the monitoring equipment, especially where the signal power lines go.

Fourth, the problem of grounding cable, in order to save costs, often use the metal rod as the down conductor of the working grounding system, regardless of "right" and "no". According to the design, the metal rod is used as the direct lightning protection system to guide the off-line. At this time, the working ground is connected to the metal rod. If there is direct lightning, there is no voltage difference between the front end of the signal lightning arrester and the rod of the metal rod. That means your Direct lightning will directly hit the signal arrester or the power arrester, which will cause the arrester to age prematurely or be damaged on the spot. Therefore, it is recommended that the downline of work should be singled out.

Five, three in one surge protector (or BNC surge protector) choice, according to the specific circumstances of the market, and time installation experience point of view, BNC signal electrophoresis protector is set for a long time in the lightning protection range, this The protection of the matter is not enough. For it, there are power surges, spikes, and burrs, which may cause surges, spikes, and burrs to start up near large-scale power tools. Close, there are changes in nearby electromagnetic fields, etc. These not only require the protection of pressure sensitive or discharge tubes, but also need a logic filter circuit to provide a safer power environment. The latter factor was ignored. Lightning protection is a complex issue. The lightning protection design of the safety monitoring system not only depends on the performance of the lightning protection device, but more importantly, the geography of the monitoring system must be taken into account before the design and construction of the monitoring system. Environment, design suitable cable deployment methods, shielding and grounding methods. In short, lightning protection design should be considered comprehensively to achieve good results.