Design of Steel Earthing Grids in India

Based upon more than ten years experience of the design of steel earthing grids in India, the paper gives information required for the design of steel earthing systems and technical, economic and practical reasons for the use of steel in preference to copper conductors. The information given in the paper includes the generalized formula for calculating the size of earthing conductors of steel, copper and other materials, basic considerations for determining corrosion allowance to be provided on the conductor cross-section for its reliable performance and those details of electrochemical corrosion in soils, the knowledge of which is essential for assessing the corrosion of conductors in soil. The problem of using steel and copper grids in the same area is also briefly discussed.