The recommended depth for buried electrical cables varies significantly based on local regulations, voltage level, and the environment. For low-voltage lines (under 1kV), a typical depth is 450-750 mm, while medium/high-voltage lines (over 1kV) require a minimum depth of 750-1200 mm. For areas with vehicle traffic, cables are laid even deeper and in protective ducts.

Best practices for installation include:

• Planning and Surveys: Always conduct a pre-installation route survey to locate existing utilities and perform soil analysis.

• Trenching and Bedding: Dig a trench of appropriate width and depth, ensuring the base is level and free of sharp objects. A layer of sifted sand or fine soil (75-100 mm) should be placed at the bottom to protect the cable sheath.

• cable laying: Lay the cable with slight "snaking" to allow for thermal expansion and ground settlement. Always adhere to the minimum bending radius specified for the cable.

• Protection and Backfilling: Cover the cable with another layer of sand, and then place mechanical protection (concrete slabs, plastic tiles) and a brightly colored warning tape (150-300 mm below the surface) to alert future excavators. Finally, backfill the trench with compacted soil.