Current development of aluminum alloy cables

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This post was last edited by yuchenchf on 2017-5-16 08:40. Aluminum alloy cables, which possess many advantages, still face difficulties in developing in the Chinese market. Statistical data shows that in China’s wire and cable market, copper wires and cables still account for over 90% of the market share. At present, the development of the aluminum alloy cable industry as a whole remains in a sluggish state. Compared to applications abroad, the United States began developing and producing alloy power cables as early as 1968, and they were introduced and used in countries such as the U.S., Canada, and Mexico. It is mainly used in construction projects such as airports, **bases, office buildings, residences, hotels, supermarkets, educational institutions, stadiums, hospitals, and factory buildings. 　　Why has the aluminum alloy cable, which has been in use in North America for over 40 years, faced difficulties in its development in China over the past nearly 10 years since it was introduced there in 2006? One of the major problems is safety hazards. 　　Unlike copper wire cables, in aluminum alloy cables, the copper oxide formed as a result of oxidation at the cable joints is an excellent conductor, which still ensures the electrical connectivity of the joints and terminals. Alumina, which is formed by the oxidation of aluminum and aluminum alloy joints, is an insulator. Its hard texture and strong adhesion make it difficult to create good electrical contacts, leading to overheating of those contacts. This is the reason behind many accidents involving aluminum alloy cables. 　　Similar accidents also occurred when aluminum alloy cables were first introduced in the United States. The main reason is that no dedicated connectors were designed for aluminum-core cables; instead, connectors used for copper-core cables were applied. This led to looseness, microscopic damage, and arcing between the aluminum wires and sockets or switches, resulting in increased contact resistance, overheating, and ultimately fires. 　　To reverse this situation, the North American cable industry has made improvements in cable products and connectors, taking the following measures. 　　In terms of materials: Alcoa in the southern United States and Alcan in Canada developed 8000 series aluminum alloys such as 8176 and 8030, improving their creep resistance ； 　　Regarding wire connections: various methods are employed to improve connection performance, including the use of tinned terminals, adding special gaskets between aluminum wires and copper terminals, applying antioxidants to the connection points, and designing specialized sockets ； 　　In terms of standards: Following tests conducted by the American UL company and the American **Fire Protection Association (NFPA), in 1985, NEC electrical codes specified that for certain types of wires operating at voltages below 2000V, aluminum conductors should be made of 8000 series aluminum alloys. In 1988, the American Society for Testing and Materials (ASTM) issued standard B800, which included 6 grades of 8000 series aluminum alloys in the standards for cable conductors ； 　　From the crisis-response measures taken by the North American cable industry regarding aluminum alloy cables, we can identify two key points: first, the crucial aspect of cable application lies in the system performance between the cable and its connectors ； II. The industry standards and specifications for aluminum alloy cables form the foundation for development. 　　Currently, in the cable market, the competition between copper and aluminum remains an unavoidable issue. However, consumers have become more mature over time, which indicates that the aluminum alloy cable market has evolved from a state of emptiness and difficult development in its early stages, through a period marked by chaos, to a more rational state today.