Skip to main content

What a power cable is

Short answer

A power cable is an assembly of one or more insulated conductors with protective layers (sheath, armour, serving) for underground or underwater power transmission. It typically has a stranded copper or aluminium core, insulation like XLPE, a metallic moisture barrier, and mechanical protection.

What is a power cable? Explain briefly.

A power cable is an assembly of one or more insulated conductors with an overall protective covering. It is used to carry electric power underground, under water, or inside buildings and substations where overhead lines are not possible.

Construction (from inside out)

   +-------------------------------+
   |  serving (jute/PVC)           |
   |  armouring (steel tape/wire)  |
   |  bedding                      |
   |  metallic sheath (lead/Al)    |
   |  insulation (paper/PVC/XLPE)  |
   |  conductor (Cu/Al, stranded)  |
   +-------------------------------+
  1. Core (conductor): Stranded copper or aluminium, for flexibility.
  2. Insulation: Impregnated paper, PVC, XLPE or rubber. Its thickness depends on the voltage.
  3. Metallic sheath: Keeps out moisture and gases.
  4. Bedding: Jute or fibrous tape that protects the sheath from the armour.
  5. Armouring: Steel tape or wire for mechanical protection.
  6. Serving: An outer jute or PVC layer that protects the armour from corrosion.

Types

Cables are classified by voltage (LT, HT, ST, EHT) and by construction (belted, screened, and pressure cables, which may be oil-filled or gas-filled).

Cables are safer, less exposed to faults and invisible, but they cost much more than overhead lines and are hard to repair.

✓ Answer checked by Claude Opus 5.5 (high effort)

Related questions

All Power System Analysis I chapter 2 questions →