HT transmission line and tower earthing

HT transmission line Earthing

1. The earth conductor is placed on the top of structure tower to provide a shield angle over the power conductor to protect against lightning stroke.
2. The shield angle is usually maintained at 25 degrees for outer and 45 degrees for the central conductor.

Specifications of tower earthing

1. Each 132KV transmission tower leg to be provided with one single peg earth electrode.
2.  The electrode length shall be 3 meters with 18 holes of 10mm at the bottom 1 m length.
3. The electrode shall be 38 mm and 3.25 mm thick.
4. All the earthing pegs shall be internally connected via 50*6mm GI flat.
5. The connection of GI flat to tower leg should be done at a height of min. 500mm from the ground level.