Metal oxide arrester
Lightning protection measures and necessity of high-voltage arrester
1. High-voltage arresters have a good development history and trend. It is continuously improved and plays an important role in power equipment. According to the order of its development, arresters can be divided into: protection gap - arrester protects two simple forms of power equipment; tubular arrester is also a protection gap, but it can automatically extinguish the arc after discharge, and is not affected by current impact and returns to its original state; valve arrester divides a single discharge gap into multiple short series gaps, which increases The nonlinear resistor improves the protection performance; the magnetic blown arrester uses the magnetic blown spark gap to improve the arc extinguishing ability and limits the internal overvoltage; the zinc oxide arrester takes advantage of the ideal volt-ampere characteristics of the zinc oxide valve plate (extremely nonlinear, that is, low resistance under high current, limiting the voltage on the arrester, and high resistance under normal power frequency voltage). It has the advantages of no gap, no freewheeling, and low residual voltage. It can also limit internal overvoltage and is widely used. Lightning arresters can not only protect atmospheric high pressure, but also protect operating high voltage. In the event of a thunderstorm, lightning will produce high voltage, which may be dangerous to electrical equipment. At this time, the lightning arrester will play a role in protecting the power equipment from damage. The important function of high-voltage arresters is to limit overvoltage to protect electrical equipment. A high-voltage lightning arrester is a device that allows lightning current to flow into the ground and prevents electrical equipment from generating high voltage. The main types are tubular arresters, valve arresters and zinc oxide arresters. The main working principles of each type of lightning arrester are different, but the essence of their work is the same, that is, to protect electrical equipment from damage. The main reason for excessive arrester leakage current is the aging of the arrester. It is recommended to regularly test the arrester for leakage current. If the leakage current is found to be too large, it should be replaced immediately to prevent the degradation of arrester performance from affecting the normal operation of the line. The excessive leakage current of the arrester is caused by some important reasons. It will produce certain changes and functions within a certain range of use, thus affecting the normal performance and value of the arrester. Only by using it in the correct way can its good value and role be fully exerted. Typically, the leakage current requirement is less than 50ua at 0.75 times the LMA reference voltage.
High voltage arrester
2. Use of high-voltage arrester
Natural lightning and the lightning impulse voltage caused by it are called external lightning, and the corresponding lightning generated inside the power system is called internal lightning. The so-called internal lightning refers to the sharp rising wave (shock wave) generated during operation due to the circuit breaker connected in the power system. With the rapid development of science and technology, electronic devices that utilize the weak properties of semiconductors are rapidly increasing around us. In this way, the machine needs to be protected not only from external mines, but also from internal mines. The so-called surge voltage absorber is equivalent to a relatively high-voltage lightning arrester in terms of its function. Therefore, the surge voltage absorber is not independent of ground. Therefore, lightning protection products such as high-voltage arresters and arresters play a certain role in preventing lightning damage. Lightning rods, high-voltage arresters, lightning protection strips (wires), arresters, wires and grounding systems can be installed on buildings for external lightning protection of buildings. When selecting a high-voltage arrester, attention should be paid to preventing direct lightning strikes during actual use. Lightning protection inside buildings: According to statistics, 80% of lightning accidents are caused by induction lightning (indirect lightning) or lightning intrusion into buildings. In particular, large foreign suppliers of process signal conditioner products regard process signal high-voltage surge arresters as their main product category. The results show that high-voltage arresters have been widely used abroad. A lightning protection device connected between a conductor and the ground, usually in parallel with the device to be protected. High voltage lightning arresters can effectively protect power equipment. When the voltage is abnormal, the high-voltage arrester will play a protective role. When the voltage value is normal, the high-voltage arrester will quickly return to its original state to ensure the normal power supply of the system. No
Lightning arrester manufacturer
