For 11kV underground installations, the cables typically have a cross-linked polyethylene (XLPE) insulation. The construction includes a conductor (aluminum or copper), a semi-conducting conductor screen, XLPE insulation, a semi-conducting insulation screen, and a metallic screen (copper tape or wires). The outer layer is an extruded outer sheath, commonly made of PVC or Low Smoke, Zero Halogen (LSZH) compounds. These cables must conform to international standards such as IEC 60502-2 and national standards like BS 6622. Key specifications include a rated voltage of 6.35/11kV, a maximum continuous operating temperature of 90°C, and a short-circuit temperature of 250°C.