In recent years, due to rising copper prices low while the price of aluminum conductor cable wire, light weight, reduce labor intensity of construction and to be welcomed. Aluminum and aluminum alloy conductor has occupied in the wire and cable industry in a certain position, according to the survey, a large domestic wire and cable manufacturers in 2014 using copper raw materials 180,000 tons, while the amount of aluminum raw materials up to 11 tons. However, aluminum and aluminum cables appear in grid construction in many problems of urban industry should receive attention.
Aluminum or aluminum alloy, both conductive properties or mechanical properties are not as copper, 20 ℃ DC resistance rate of 2.82 × 10ˉ6 Ω • cm, about 1.64 times that of copper. Conductivity of aluminum is lower than copper is unquestionable, aluminum alloy conductor alloying elements copper, iron, magnesium, rare earths and other post is only partially improved mechanical properties, the conductivity does not increase declined. Where annealing exquisite person, it may be very close to the conductive properties of aluminum electrician. Resistance "cable conductor" the national standard GB / T3956-2008 aluminum and aluminum alloy conductor to take the same value. So, in theory, even if high-quality aluminum alloy conductor, conductor cross-section when it is copper conductor cross-section of 1.5 times, in order to achieve the same electrical properties of copper conductor (ampacity, voltage drop, etc.).
Brittle aluminum conductors the joint easily broken, but also because of creep characteristics, so that the reliability of the joint is reduced. That is, so-called creep at elevated temperatures (e.g. 70 ℃) and a greater pressure (e.g., clamping bolts), the growth over time of molding degeneration. Causing loose joints, so reduce the reliability of wire and cable connectors, or even damage the main reason. Even after a long journey, but also to find some way to deal with, such as strengthening the inspections, regular reinforcement tighten bolts, but not as good as copper joint reliability is an indisputable fact.
For aluminum power cable, because the conductor is aluminum electrician added trace elements. Improved mechanical properties, such as flexible Utsubo optimization, improve creep resistance, but one of the key technologies of the aluminum cable connector. Joint materials and technology is an important factor affecting the quality, the introduction of technology in addition to the sale of cable and cable manufacturers outside also provide technical services. To joints reliable suppliers must appoint professionals to guide the construction, and therefore it is much higher than the price of aluminum cable. Nevertheless still a great profit margins, manufacturers from the beginning of the two, suddenly soared to hundred. Due to the current enterprises are by their own corporate standards, in fact, looks like the same great quality difference.
To ensure the safety of the use of aluminum cable, aluminum cable must be in line with the standard requirements, but also the need for strict protection of the construction process, coupled with consistent performance matching aluminum cable connector used together.