The pulse national standard has repeatedly stressed that the system should have good grounding. The good grounding of the system is also considered as an effective solution for the lightning protection system of the equipment. It has become an important task in engineering installation. However, how to distinguish the grounding effect? ​​The role of grounding Is it just lightning protection so simple? Pulse electronic fence system grounding effect For the pulse electronic fence system, the grounding device is mainly composed of the grounding body and the grounding wire. The two are installed together to complete the front end fence and the pulse host grounding construction. According to the grounding purpose, the grounding can be divided into protective grounding and working grounding. ·Protective grounding The so-called protective grounding is a technical measure to prevent personal electric shock accidents and ensure that the pulse equipment is not damaged. It can also be divided into lightning protection grounding and chassis safety grounding. One end of the arrester is connected to the pulse front end alloy wire, and one end is grounded, whether it is direct lightning or lightning, static induction, electromagnetic induction and lightning. The safety grounding of the casing is to ground the casing of all metal equipment under the conventional mains power supply system. The pulse electronic fence system is mainly for grounding the pulse box rainproof box. First, to prevent the accumulation of electric charge on the rain box casing, static electricity is generated. Discharge may affect the safety of the main unit and personal safety. Secondly, in order to prevent damage to some of the live insulating materials or other circumstances, the unpowered parts are charged, which is a way to protect personal safety. Pulse host, rainproof case, grounding ·Working ground For the pulsed electronic fence system, the working grounding is mainly a technical means to ensure the stable implementation of the host function. Among them, good grounding effect is an important factor to realize the reliable "touching net" function of the pulse host. At the same time, the standard working grounding installation also ensures the stability of the circuit system work, and cooperates with the host to resist the external electromagnetic field interference, which can effectively solve the problem that the pulse products in the substation and the like cannot work normally. The grounding effect of the pulsed electronic fence system is obvious. In the engineering installation and construction, the grounding work is very important, combined with the technical advantages of the pulse products, to ensure that the entire pulsed electronic fence can operate normally and stably under complicated conditions. Poor grounding of the pulse system will cause multiple device problems The grounding technology is applied to the weak current system of the perimeter alarm pulse product, which can effectively improve the stability of the equipment in complex environments. At the same time, in the lightning weather, it also shoulders the functions of protecting personal safety and protecting the host equipment. However, the unreasonable grounding technique, which causes the difference in grounding effect, will directly affect the normal use of certain functions of the pulsed electronic fence system. First, the grounding technology is one of the important contents of the electromagnetic compatibility technology of power electronic equipment, and is also applicable to the pulse electronic fence system. Good grounding technology allows current to pass through the grounding wire and is compatible with the earth without voltage drop. However, due to unreasonable grounding, electromagnetic interference, such as common ground interference and ground loop interference, may be introduced, resulting in an electronic fence. The equipment does not work properly under electromagnetic field and lightning weather conditions. Second, the pulse electronic fence sets a new alarm concept for deterrence, blocking, and alarm. When an intruder invades, the high-voltage pulse power blocks the intruder with high-voltage pulse electric shock without affecting the intruder's personal safety. The bad pulse host is grounded, and when a person touches, a complete current loop cannot be formed. After the current is suspended, the electronic fence is weakened, and the intruder is less difficult to climb. In addition, the grounding effect is not good, and the voltage of the front fence alloy line fluctuates. And not uniform. Good grounding, fence forming loop, strong combat Third, when the pulsed electronic fence is in lightning weather or equipment failure, the protective grounding bears an important duty to ensure personal safety and equipment safety. Without good grounding effect, safety hazards will occur. Obviously, the grounding effect of the pulsed electronic fence system directly affects the stable and safe operation of the system. How to carry out standardized grounding installation, how to adjust the grounding according to local conditions, and how to evaluate the grounding effect are all urgent problems for engineering operators. Exploring how to broaden the grounding of the extension electronic fence In the national standard of "pulse electronic fence and its installation and safe operation" (GB/T 7946-2015), it is clearly stated that the pulse electronic fence system should have a reliable grounding system and put forward many requirements for grounding work, each of which All become the elements to assess whether the grounding work is standardized. In this paper, the grounding of the T6/T8 catenary anti-bypass pulse electronic fence grounding with the standardized specification is grounded as a model. In practice, how to connect to the place can achieve a good grounding effect. · The grounding system remains relatively independent grounded According to the design requirements of the pulse electronic fence system, the grounding of the front fence arrester and the grounding of the pulse host must be relatively independent. Take the extension T6211 four-wire double-zone pulse host as an example, there are three grounding piles, one for each side of the fence and one for the rain main box (the rain box and the pulse host share the grounding pile). To avoid mutual interference, the grounding piles on both sides of the fence are more than 10M away from the intermediate rain box grounding pile. In addition, the system lightning protection grounding system, RS485 communication line shielding grounding system, and working grounding system are independent, in line with national standards. ·The grounding body is buried at least 1.5M deep, and the grounding resistance is less than 10Ω. The wide extension T6/T8 grounding body is made of high-cost triangular iron, and the grounding wire is made of copper wire. In theory, the buried depth of the grounding body needs to be about 1.5M-2.0M, and the grounding line can also be generally applied to the BV6 level. In addition, judging the quality of the grounding effect, the grounding resistance value becomes an intuitive consideration data. After the construction is completed, the grounding shaker is used for measurement. Most of the projects can also generally meet the national standard requirement of less than 10Ω. Grounding body: triangular iron However, in practical applications, the grounding work is restricted by many factors, and the construction becomes more complicated. China has a vast territory, and the surface composition of each region is different. In addition, the installation environment with different differences and different protection requirements have large gaps in grounding resistance. Even in the same project, the resistance values ​​measured by the shaker are not uniform, and the local conditions become grounding work. Guidelines. According to the simple division of the north and south regions, the surface water, salt and electrolytes in the south are sufficient. The grounding body is buried 1.5m, and the resistance value can basically meet the requirement of less than 10Ω. For some soil-poor areas in the north, the grounding resistance is very large. Choosing to dig the soil to a damp place, adding a resistance reducer, and reducing the surrounding soil resistivity is a common method, but the palliative is not a cure. Look for a more humid grounding point, use multiple grounding bodies to connect to ground, choose a better grounding body, or bury more deeply, etc., the cost does increase, but it can achieve long-term good grounding effect, for this kind Projects, regular maintenance are also very important. In the specific grounding construction, many small details should be paid attention to. For example, in the connection between the grounding wire and the grounding body, in order to avoid oxidation in the long-term use, the resistance value rises, and it is necessary to weld the two and paint best. In addition, the protection level and installation environment of the project site are different. It is also necessary to select BV10 and BV16 copper wires with stronger wire diameter and stronger conductivity. For example, large-scale hydropower stations, due to their special environment and high requirements for grounding, generally use BV10 copper wires. Improve the protection performance of the fence system. Some of the pulse systems are interfered by lightning. In addition to the technical failure of the product itself, the grounding technology of the equipment is easily overlooked, but it is an influential factor in engineering installation technology that complements the product technology and cannot be avoided. The grounding technology of pulse electronic fence system involves many details. In actual installation, it is necessary to comprehensively consider various factors such as national standard, grounding purpose, project environment and security demand level. Selecting the appropriate grounding method according to local conditions can effectively protect the user's personal safety and safety. Pulse products operate stably. Tile Adhesive Gmk70M,HEMC Gmk70M For Tile Adhesive,70000 Viscosity HEMC For Tile Adhesive,HEMC For Tile Adhesive Shijiazhuang Shangzu Building Materials Technology Co.,Ltd. , https://www.shangzuchem.com
How to correctly install pulse electronic fence system to solve lightning interference
Release date: 2018/11/9 11:58:13