Problems existing in the operation of distribution arrester manufacturers and how to deal with them
1. Installation by lightning arrester manufacturer
1.1 Problems and solutions
Distribution type arresters are generally installed on the upper side of the high-voltage fuse. According to the regulations: "The height of the transformer base from the ground shall not be less than 2.5m." In this way, when the arrester is damaged or causes grounding, short circuit, calibration and replacement, the entire 10kV line will be powered off, and it is not convenient for installation and disassembly. In addition, the ground lead of the distribution type arrester is too long from the ground and does not meet the relevant technical requirements. In view of the above problems, we changed the installation position of the distribution arrester and installed it on the lower side of the high-voltage fuse. This does not affect the protective effect and range of the arrester, but also facilitates the normal assembly and disassembly of the distribution arrester, reducing the number of power outages on the entire line. At the same time, when the performance of the distribution arrester decreases and is struck by lightning, the power frequency freewheeling increases, which will inevitably lead to the arrester itself malfunctioning and the distribution transformer fuse blowing, which plays the role of isolating the fault point, reducing the chance of single-phase grounding or short circuit tripping of the line, and improving the reliability of the power supply.
1.2 Precautions for installing distribution type arresters
The installation point of the distribution arrester should be greater than 0.7m away from the fuse to ensure that the safety distance specified in the "Safe Work Regulations for the Electrical Industry" is met during maintenance. The lead length of the distribution arrester should be as short as possible and the contact should be reliable. The conductor should use 35~50mm2 black glue wire to reduce the lead reactance and reduce the residual voltage. The distance between the distribution arrester and the transformer should be greater than 2m to increase the inductance on the wire and improve the relative lightning resistance level of the transformer. When the distribution type arrester is removed and reinstalled, it cannot be tied with iron wires, wires, etc., but should be reinstalled with special clamps to prevent creepage. In addition, the down conductor of the arrester must be connected well and tied to the cross arm and pole to prevent grounding, short circuit or damage to the transformer caused by the explosion of the arrester.
2. Problems existing in the operation of distribution arrester manufacturers
2.1 Distribution-type arresters are difficult to install due to damage, breakdown, and corrosion. It is difficult to source funds and bear costs. In addition, village electricians have a weak sense of responsibility and have a fluke mentality. They cannot install and replenish them in time, which objectively leads to a low installation rate and insufficient installation quantity of arresters.
2.2 Due to the heavy workload of regular calibration of distribution arresters, a considerable number of arresters have not been calibrated for many years, resulting in ineffective arresters still operating online.
2.3 Due to the low sense of responsibility of construction, installation, and maintenance personnel, most distribution-type arresters have various abnormal conditions such as loosening, tilting, incorrect installation positions, and lead wires falling off during operation.
2.4 The quality of distribution-type lightning arresters is low and cannot provide effective protection.
2.5 The grounding down conductor is broken and twisted, and some even use iron wire instead of the ground down conductor. In most cases, the grounding resistance is too high.
3. How to rectify distribution arresters
3.1 Increase publicity and education to let users understand the necessity and importance of installing lightning arresters.
3.2 Enable electricians to master the installation process of lightning arresters and standardize the construction without leaving any sequelae.
3.3 Strengthen operation management and conduct regular inspections, inspections, and verifications. Unqualified arresters cannot be operated online.
3.4 Actively promote the use of zinc oxide arresters.
3.5 Carefully check the lightning arrester grounding bodies and transformer grounding bodies of all distribution transformers in the jurisdiction. Those with high grounding resistance must be thoroughly dealt with.
Yichang Hengyuan Technology Co., Ltd. specializes in the production of European-style cable joints, plug-and-pull heads, cable branch boxes, American-style elbow joints, high-voltage vacuum circuit breakers, high-voltage load switches, arresters, zinc oxide arresters, tank arresters, over-voltage protectors, counters, monitors, heat-shrinkable cable accessories, Manufacturer of cold shrink cable accessories, T-heads, wall bushings, European cable accessories, American cable joints, transformer neutral point protection devices, fuses, isolating switches, PT cable heads, elbow cable joints, 10kV outdoor terminals, switch cabinets, cable intermediate joints, cable accessories and other products
