A thermal backfill is a critical component of the trench design for 220 kV cables. The primary purpose is to create a consistent, low-resistivity thermal envelope around the cable.

• Heat Dissipation: The backfill efficiently conducts heat away from the cable to the surrounding soil, preventing the conductor from reaching a temperature that could degrade the insulation.

• Trench Design: The trench is precisely designed to specific depths and widths to accommodate the cables, ensuring proper separation and thermal management. A protective layer of bricks or concrete slabs is installed over the backfill to prevent any future damage from excavation.