Specification required for Earthing
Download as DOCX, PDF0 likes218 views
The document provides specifications for proper earthing, including that the earthing electrode must be at least 1.5 meters from the building, be made of the same material as the earth wire with a cross-sectional area between 0.02 and 0.1 square inches, and be a galvanized iron pipe of at least 12mm diameter and 32cm length buried in a mixture of coal and salt. It also specifies that all earth wires must terminate securely at the main circuit board and ensure low enough resistance for protective relays and fuses to operate.
Specification required for Earthing
- 1. Specification required for Earthing 1) Earthing electrode should be placed at least one and half meter away from the building 2) Earth wire should be same material with earth electrode 3) The minimum sectional area of earth wire should be greater than 0.02 sq. inch and less than 0.1 sq. inch 4) The size of earth conductor should not be less than half of the section of a line conductor 5) The earth electrode should be taken as GI pipe with minimum diameter of 12 mm and at least 32 cm length 6) Coal and salt mixture with loose soil should be filled around the earth electrode 7) All the earth wire run along with the sub-circuits should be terminated hooked firmly at the main board 8) The earth resistance should be low enough to flow of current sufficient to operate the protective relays and blow fuses