Underground cable
An insulated electrical connection below the surface.
A conceptual three-core cable beneath a ground surface. The layer arrangement is illustrative, not a specification.
An underground power cable has conductors enclosed in electrical insulation and protective layers. It may be installed directly in the ground, in ducts, or in tunnels.
Insulation replaces open-air separation
An underground cable has one or more conductors surrounded by engineered insulation and protective layers. Depending on its voltage and design, it may also include metallic screens, sheaths, and armor. The simple cross-section omits many of these layers.
Installation can use buried ducts, direct burial, or tunnels. Heat must escape through the surrounding materials, so soil conditions, spacing, and installation method affect the current rating. Cable joints and terminations are important parts of the system too.
Why it matters
Cables allow circuits to run beneath streets and other constrained spaces, with different installation and maintenance tradeoffs from overhead lines.