The typical structure of a mineral insulated cable is s […]
The typical structure of a mineral insulated cable is shown on the right. The conductor, magnesium oxide and sheath are subjected to multiple combined rolling, and the three are highly pressed and the magnesium oxide has a high degree of compactness. If the cable is required to have corrosion resistance, an outer sheath can be extruded outside the copper sheath. Under normal circumstances, a layer of outer sheath is extruded. In general, the conductor and the sheath are made of a copper material and the insulating layer is made of a magnesium oxide material.
The conductor size of the distribution cable is quite large, ranging from 1mm2 to 400mm2, and the number of cores varies from 1 to 19. Generally, the conductor cross section of a single-core cable is larger than 25mm2, and the multi-core cable has 7 cores and 12 cores. In general, the 19-core conductor has a relatively small cross section.
The raw material used in the continuous production process of copper strip longitudinal welding is phosphorus-containing oxygen-free copper strip, silicone oil-added magnesia powder, and coiled copper conductor. Phosphorus-free oxygen-free copper strips weigh up to 700kg, and coiled copper conductors weigh up to 1 ton. The cable for the filling or porcelain column assembly process can only reach about 200kg, so from the source, the continuous production process ensures the supply length of the raw materials. In theory, in the continuous production process of copper strip, the quality of raw materials is guaranteed, and the electrical stability is high. A 2L1.5 cable can reach about 8 kilometers, due to the constraint of the wire-receiving device, a 2L1.5 The cable can be up to 4 kilometers long.
The conductor material used for mineral insulated cables is a solid, annealed, high conductivity, oxygen-free copper of approximately circular cross section. Two necessary conditions for satisfying the conductor material are the most basic high conductivity for efficient transmission of electrical energy and the extensibility of materials that meet the process requirements. The flexible copper with high conductivity can meet the requirements of most wiring cable conductors. The oxygen content of oxygen-free copper is very low. The structure of this copper is a uniform single-phase structure, which is very beneficial to toughness. The rollability of oxygen-free copper is superior to low-oxygen copper rods in all wire diameters.