Underground electric transmissions are increasingly important for resolving today's power supply challenges. Electric power continues to be a primary source of energy for both residential and commercial establishments. Traditionally, the transmission method has been overhead cables, but there is a need for change as other structures compete for this space. Underground transmissions are an ideal alternative, especially for crowded cities with limited aerial space. Certainly, the success of transmitting power by underground means requires quality cables that can withstand the operational challenges. Here are some of the cable technologies you need for efficient underground electrical supply installations:

Fluid-filled Cables

Fluid-filled cables are one of the earliest technologies in underground electrical installations. These cables feature a centralised paper conductor wrapped in paper insulation. The combination is impregnated with special fluids under immense pressure. The fabricators also wrap metallic tapes over the insulation to reinforce the paper insulation and maintain the fluid in its chamber.

An aluminium or lead sheath covers the whole set-up. However, the sheath is susceptible to damage whenever there is an ingress of water into the cable. The cables need an external plastic sheath for enhanced protection against the ingress of water. Fluid-filled cables offer reliable structural integrity. They can be in place for a long period without deteriorating.

Mass Impregnate Non-draining (MIND) Cables

Mass impregnate non-draining cables are another great alternative that you can use. They feature robust paper insulation, and they are ideal for low voltage applications in substations. Usually, the paper insulation comes with non-draining insulating fluid to eliminate the risk of losing current to the surrounding soil. On the downside, these cables are susceptible to high technical stress and unsuitable for transmissions of more than thirty kilovolts.

Cross-linked Polyethylene Cables (XLPE)

Cross-linked polyethylene cables, abbreviated as XLPE, have excellent electrical characteristics that make them suitable for underground electrical applications. Modern XLPE cables come with central conductors insulated by cross-linked polyethylene materials. The insulating material is extruded over the conductors, eliminating the need for an insulating fluid. Overall, the elimination of an insulating fluid delivers robust cable physical properties. You will have cables with minimal maintenance needs, though the cables do need examining regularly.

Paper Polythene Laminated Cables

You can also do your underground installations using paper polythene laminated cables. Just as the name suggests, the insulation comes wrapped over the conductor materials. The primary insulation here is XLPE material or paper. Paper polythene laminated cables have similar physical properties with fluid-filled cables. 

For more information, contact a power installation company.