The package (or insulated) cables are used for multi […]
The package (or insulated) cables are used for multi core and low voltage cables. The package type is used for package insulation and insulation for oil impregnated paper insulation.
Turnkey type is first prepared in each phase of insulated wire core stranded cable filled, and then the metal layer (concentric conductor and metal sheath, shielding or armour), finally extruded outer protective layer formed with insulation type in insulation wire stranding, the outside of the cable core again a certain thickness of the insulating tape around the package (the relative phase between and relatively between the dielectric strength of the same), drying after impregnation extruded lead sheath, the extruded outer protective layer.
Turnkey type or belt type cable insulation electric field distribution is very uneven, the insulation and filler are subjected to an electric field in the changing times, the power line has radial component, also has the tangential component, so called non radial type cable.
The tangential field components to produce plastic insulated treeing, and filling ratio of the insulation resistance of electric intensity is low, so that the entire cable electric strength is not high, therefore, the structure for the voltage level of 0.6/1kv1.8/3kv, XLPE and EPR PVC insulation insulation insulation power cable (HEPR). 1KV low voltage cable, electric field strength, high insulating electrical performance requirements, in addition to light music on the cable section using multi core circular package structure, cable cross-sectional area of the larger the fan or tile type multi core structure, such as the four core cable three core cable, with three-phase three-phase system four wire system, five core cable three-phase and five wire system, in order to save materials. 1.8/3kv cable must have a metal shielding layer, core system mainly adopts three round type structure.