What is the "screen of the cable" for medium/high voltage cables?
In high voltage cables, especially underground, the cable is shielded, or screened, with an earth conductor.

If a digger, or something similar, should cut through the cable it will generally connect the conductive inner core directly with the protective screen around the outside causing the fuse to blow at the substation (or whatever feeds the power) rather than travelling up through the digger and killing the operator.



In those cables, from the inside out, you have the power conductor(s) (aluminium), insulation (white), plastic sheath (black), copper shielding (orange), more plastic sheath (black), armouring (steel wires), and finally the outer plastic sheath (black).