Analysis on the current situation of low voltage s

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Analysis on the current situation of low-voltage switchgear in China

low-voltage switchgear is responsible for the control, protection, measurement, conversion and distribution of electric energy in the low-voltage power supply system. Since low-voltage switchgear sets go deep into production sites, public places, residential houses and other places, it can be said that all places where electrical equipment is used should be equipped with this equipment. About 80% of China's electricity is provided through low-voltage switchgear sets. The development of low-voltage switchgear sets is rooted in the material industry, low-voltage electrical appliances, processing technology and equipment, infrastructure construction and people's living standards, Therefore, the level of low total experimental pressure switchgear reflects a country's economic strength, science and technology, and living standards from one side

before the 1970s, China's low-voltage switchgear was basically in a stagnant state, which was mainly reflected in the single product variety, poor quality, low technical parameters, backward process equipment, unchanged product types for many years and backward standards (there was only one standard jb617 at that time). Since the 1980s, the national economy has developed rapidly due to the implementation of the R reform and opening-up policy. With the increase of investment in economic construction, especially in infrastructure and electric energy, the low-voltage switchgear industry began to have a turn for the better. The market demand increased year by year, which also greatly stimulated the development of the industry, mainly reflected in the large increase of manufacturers, the accelerated renovation of products, the increase of varieties, and the gradual convergence of product standards to international standards. The technical performance parameters of the products have been significantly improved, and the processing technology and equipment of the factories have been significantly improved. Hundreds of manufacturers have introduced foreign advanced CNC sheet metal processing equipment, and some factories also have flexible processing lines, and their sheet metal processing technology has reached the international level. In addition, there are also professional manufacturers and electrical accessories manufacturers in the industry that will cause the test pieces to discount a batch of profiles and cabinets around the selected circular axis

At present, the manufacturers of low-voltage distribution products in China are mainly distributed in East China, South China and North China, especially in Jiangsu, Zhejiang, Guangdong, Fujian and Beijing Tianjin. The main reason is that the economy in these areas is developing rapidly, and the production capacity and product level are relatively higher. In the northwest and northeast regions, except for individual enterprises, the overall level is relatively poor

at present, China has developed more than ten kinds of distribution equipment, including fixed panel type, fixed separation type, extraction type, mixed type, intelligent type, etc. the product design level has reached the international level in the mid-1990s

2 busbar trunking products

the processing and production process of busbar trunking products is relatively simple, so generally, manufacturers that can produce low-voltage complete sets of switchgear can produce busbar trunking. In addition, there are some manufacturers specializing in busbar trunking

as the development of China's plastic machinery is attracting global attention, the economic situation of each region is different, so the enterprise distribution and output value are also very different. In coastal and economically developed areas, bus duct production enterprises started earlier, developed faster and have a large number. For example, Jiangsu, Zhejiang, Shanghai, Guangdong and other places. However, due to the low technical content of the product, the requirements for the process and processing equipment of the factory are also low, and the low investment and quick effect, the strength of the manufacturers is uneven, which reflects that there is a considerable gap in product quality. In general, there is still a big gap between the level of bus duct products in China (except for some joint ventures) and foreign products

although the output and output value of low-voltage switchgear in China have been greatly improved, the product variety and performance are far from meeting the market demand. On the one hand, the competition between several types of products is very fierce. On the other hand, some products cannot be produced, and the domestic market is occupied by foreign manufacturers. The main problems existing in China's low-voltage switchgear industry are as follows:

(1) the product pattern is not reasonable. The low-voltage switchgear shall have the characteristics of multi-level and multi variety. The so-called multi-level means that similar products should have high and low differences in technical performance, parameters, functions, structure, installation and other aspects to meet the use needs of different industries. Multi varieties refer to the products that meet the needs of different use environments, such as moisture-proof, dust-proof, anti-corrosion, waterproof and other products used on site. At present, the vast majority of products that can be supplied in China are products used in general environment. Fixed interval products with higher parameters, high protection level, high degree of automation and multifunctional products are basically blank

(2) the independent development ability of the enterprise is poor. The characteristics of this industry are that there are many manufacturers, but few of them are large-scale. The vast majority of manufacturers have weak technical strength and do not have the ability to independently develop products. They are basically produced through technology transfer or imitation of the industry. Therefore, the product types are concentrated and the market competition is fierce. Although a few enterprises have the ability of self-development, due to the long cycle of opening the market, plus the difficulties in the above aspects, and once a certain market scale is formed, other factories can easily copy and enter the market, which seriously affects the initiative of enterprises to develop their own products

(3) there is little difference in product quality, and the products are nameless. In order to improve the processing and product quality of enterprises, many manufacturers have introduced high-precision sheet metal processing equipment, but they are relatively backward in the assembly process, bus processing process and equipment. All enterprises are at the same level. At present, several domestic best-selling products have professional profile manufacturers, auxiliary parts manufacturers, and even shell manufacturers. In order to shorten the production cycle and meet the needs of diversified markets, Purchase the shell directly for assembly. In this way, even with high-precision sheet metal processing equipment, it is difficult to give full play to its advantages. In this case, it is very difficult for the transmission system to produce high-quality famous brand products

(4) main problems of low-voltage switchgear:

① materials used in low-voltage switchgear: at present, there are many low-voltage switchgear accidents caused by unqualified flame retardance of insulation materials in China

parts made of insulating materials have poor insulation performance. The main performance is that the insulation treatment is not carried out according to the process requirements, which affects the insulation performance, or the insulation performance is significantly reduced due to the use in wet conditions. The sealing strip used for waterproof, dustproof and improving the protection grade can not be used for a long time because it is easy to age. Generally, it will be aged and deformed within 1 ~ 2 years, and can not achieve the purpose of long-term waterproof and dustproof. As the main conductor of low-voltage switchgear, the copper bar often leads to low current carrying capacity and heating due to processing capacity, copper content and other reasons, which reduces the actual current carrying capacity of the device and cannot meet the design requirements

② auxiliary parts used in low-voltage switchgear. Such accessories mainly refer to primary and secondary connectors and wiring terminals. At present, there is a big gap between China and foreign countries in terms of primary and secondary connectors and terminals

③ components. The level and quality of domestic components are uneven, and counterfeit and shoddy products flood the market, which is also an important reason affecting the quality of low-voltage switchgear in China


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