The cable core contains the conductor through which power is transferred. The rest of the core consists of screens, insulation, and sheathing to protect the conductor and prevent short circuits.
Who supplies them
Cable cores are typically manufactured by the cable manufacturer. Usually, complete cable cores are manufactured and assembled at the same site to reduce the transportation costs of the different components.
An export cable core has the same components as an array cable core and uses mostly the same materials.
HVAC and HVDC export cables are also typically insulated with XLPE. HVDC systems have traditionally used mass impregnated cables with paper-based insulation as they can be manufactured and installed in long lengths and are available at higher voltages. Modern HVDC cables mostly now use XLPE insulation as XLPE can operate at a higher temperature and are lighter so easier to handle during installation.
A 220 kV AC subsea cable conductor typically has a cross-sectional area of between 800 mm2 and 1,600 mm2 with 23 mm of insulation.
A 320 kV DC cable conductor typically has a cross-sectional area of between 1,000 mm2 and 2,500 mm2 with 25 mm of insulation.