Mining cableIt is divided into armored cableRubber sheathed cableAnd plastic cable. 1. Armored cable The so-called armored cable is to use steel wire or steel tape to armor the cable.Its biggest advantages are high insulation strength and strong tensile resistance, so the steel wire armored cable is suitable for use in vertical shaft or steeply inclined roadway, and the steel belt armored cable is suitable for use in horizontal roadway or gently inclined roadway, which has been removed and will not be introduced. 2. Rubber sheathed cable Rubber sheathed cables are divided into ordinary rubber sheathed cables, flame retardant rubber sheathed cables and shielded rubber sheathed cables.For the power supply of underground mobile equipment, rubber sheathed cables with good flexibility and flexibility are often used. The internal conductors of ordinary rubber sheathed cables have four conductive cores, three of which are main cores (thick), and the other is thin, which is ground wire.In addition to the above four core rubber sheathed cables, there are also two core, three core, six core, seven core rubber sheathed cables.In rubber sheathed cables with more than four cores, except for three main cores and one ground wire, the rest are control cores for control circuits.The outer sheath of ordinary rubber sheathed cable is made of natural rubber.Since natural rubber can be burned, and the gas decomposed during combustion can support combustion, which is easy to cause fire, it is not suitable to use ordinary rubber sheathed cables, especially in coal mines with gas and coal dust explosion risks. (2) Flame retardant rubber sheathed cable.The structure of this cable is the same as that of ordinary rubber sheathed cable, except that its outer sheath is made of neoprene.Neoprene can also burn, but it decomposes to produce hydrogen chloride gas during combustion, surrounding the flame and isolating it from the air, so it will extinguish quickly and will not continue to burn along the cable.Therefore, the flame-retardant rubber sheathed cable should be used underground in coal mines. (3) Shielded cable. 1 - Conductive rubber cushion core; 2 - Outer sheath; 3 -- Main core wire; 4. Insulation of main core wire; 5 - Main core wire shielding layer; 6 - Ground wire The shielded cable is mainly used in the working face of the mining area to improve the safety of the work.The shielding layer materials include semiconductor materials and nylon mesh materials.In addition to the general structure of shielded cables mentioned above, there are shielded cables that supply power to kV semi fixed equipment, MCPTJ cables that supply power to kV mobile (units), and 6kV MYPJT double-layer shielded high-voltage cables that supply power to mobile equipment. One of the advantages of shielding is that it can avoid the serious accident of phase to phase short circuit when the insulation of the main core of the cable is damaged.Another advantage is to avoid the danger of electric shock caused by cable damage.It is precisely because the cooperation of shielded cable and leakage detection relay can cut off the power supply of fault line in advance, which effectively prevents the generation of leakage spark and short circuit arc.Therefore, it is particularly suitable for places with gas or coal dust explosion risk and electrical equipment that moves frequently, that is, power supply system of mining face. 3. Plastic cable The main structure of this kind of cable is basically the same as the two types of cables mentioned above.But its core wire insulation and outer sheath are made of plastic (PVC or cross-linked polyethylene). Its advantages are: high allowable working temperature, good insulation performance, corrosion resistance of sheath, unlimited drop of laying, etc.If the cable is armored outside, the use conditions are the same as those of armored cable;If there is no armor outside, the use conditions are the same as those of rubber sheathed cables.Therefore, if conditions permit, plastic cables should be used as far as possible.
