After the insulated core of each phase is made, a metal […]
After the insulated core of each phase is made, a metal shield or a metal sheath (lead sleeve or aluminum sleeve) is first wrapped, and then filled with a cable, a spacer sleeve or an inner liner, a metal armor and an outer sheath Into the multi-core cable, called split-phase shielding (or split-phase lead package) cable.
Split-phase shielded cable can shield the electric field in each phase of the insulation layer, each phase of the metal shield without electric field, that is, low dielectric strength of the filler is not affected by the electric field, the power lines along the insulation core of each phase Radial (also known as radial cable), no tangential field strength components.
Due to the phase-separation shielding insulation resistance of the cable breaking resistance than the much higher than the package type, the voltage level used to improve a lot. Therefore, 6KV and above the use of round-phase multi-phase power cable and shielded structure, in order to improve the insulation resistance to breakdown strength, larger cross-sectional area of the cable can be used single-core structure.