Shielding of cable copper strip and role of steel tape armour
Cable with copper tape shielded and steel tape armoured role is used for shielding function, avoid the facilities on the outside of the high voltage alternating current and signal caused by steel or aluminum armored cable interference to strengthen the mechanical performance of the cable, the cable can withstand external mechanical pressure. Shielded cables are shielded by copper strips or braided copper wires to isolate electromagnetic interference.
The concept of Conductor: that is, a metal carrier material that allows current to flow smoothly. Conductors must have good electrical conductivity, physical and mechanical properties, technological properties, and corrosion resistance. In terms of conductivity, the metals are silver, copper, gold, aluminium, nickel, steel and alloy. But because of the high price of metal silver, so we use copper wire in the cable, usually at 20 degrees centigrade, the resistivity of copper is 0.0175 ohms mm2/m. In order to ensure that the conductor can fully meet the cable's proper performance, we choose oxygen free copper in the cable conductor. Oxygen content is not greater than 0.03%, the total content of impurities is not greater than 0.05%, copper purity of more than 99.95% of copper is called oxygen free copper. Oxygen free copper has no hydrogen embrittlement, high conductivity, good processability, weldability, corrosion resistance and low temperature performance
The concept of insulation: the so-called insulation is to use insulation materials and materials to live the body wrapped and closed, in order to isolate the charged body or different potential conductor, so that the current flow through a certain channel. Insulation rubber must have good dielectric properties, high insulation resistance and compressive strength, excellent physical and mechanical properties, and a certain plasticity, easy to process and soft, easy to install and use. The insulation materials of rubber sheathed cables are made of natural rubber (NR), styrene butadiene rubber (SBR), three yuan ethylene propylene rubber (EPR or EPDM) and so on. But because the new standards of insulating materials must be through the air missile test, so now many enterprises with three yuan of pure EPDM or chlorinated polyethylene (CPE) with three yuan and ethylene propylene rubber materials used to meet the standard requirements.
