10
Mar

Power Cables

At the present time to replace the power cable insulated with impregnated paper (BIP) and polyvinyl chloride (PVC) plastic comes with power cable xlpe insulation (XLPE). An example would be cable VVGng hp. In Therefore, most manufacturers of power cable master the production of this product. To broaden your perception, visit patrick montgomery. Let's look at the advantages and disadvantages of different types of insulation of power cable. Power cable to all the above insulating material has a fairly good dielectric characteristics. However, all these insulating materials are significantly different from each other.

This is due to their different chemical composition and properties. For example, pvc plastic, being a polar polymer, has lowered the dielectric characteristics as compared with non-polar polyethylene or impregnated paper, which leads to increased losses in the insulation. However, plasticized pvc – a material that is not flame retardant. Power cables with paper insulation must include in its design the metal shell to mechanically protect the insulation and prevent the radial penetration of water into the power cable. Power cables with paper insulation and lead sheath is suitable for installation in damp soils, and, if special protective integument, and under water. Power cable with xlpe insulation (XLPE) for the protection of the radial penetration of moisture requires a special metal layer of alumopolymer tape or aluminum or lead sheath.

Power cable with XLPE-insulated 10-35 kV in the present time in Russia decided to produce a single-conductor design. Power cable with xlpe insulation is designed for installation only in canals or ditches with the installation of additional protection against damage to the cable, since this design does not permit the use of steel protective covers on the cable. Power cable with paper insulation has one more advantage. Power cables with paper insulation is made with bronepokrovom steel tapes or wires that protect the cable from damage when installing or operating. In this case, power cable with paper insulation has a sector shaped conductors that can significantly reduce the size of the product, compared to cables having round conductors. At the same time the power cable with paper insulation has a significant drawback: the laying of cables on vertical routes and the large difference between levels of laying maslokanifolny composition impregnating the paper insulation, has a property drain, with paper insulation depleted and has a tendency to premature aging. To reduce this effect applies the power cable with non-slumping preservatives. Power cables with polymer insulation (XLPE) has no such drawback. One the most important characteristics of insulating materials – is permissible heating temperature of conductors – the maximum temperature at which the insulating material does not lose its properties over a long time. The higher the score, the higher the permissible load currents, which can be passed through a power cable for a long time. Long-term allowable heating temperature of XLPE-insulation is significantly higher than that of other materials used for insulation of power cables, as xlpe – thermoset material. In Russia, vvg copper cable with plastic insulation and the shell has been used for several years. Skeptics may say it's too short term to assess the reliability of cable products in comparison with traditionally used power cables with IL-insulated, which is used for more than a dozen years. However, it should be noted that overseas this experience is much longer. In conclusion, we say that the various cable designs have their advantages and disadvantages due to their design and material used for insulation. Therefore, when the use of any cables must be considered conditions of laying, operation and requirements for the reliability of cable lines.

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