For providing good earthing the following are recommended specifications as per ISI

1. The earthing electrode should be situated at a place at least 1.5 meters away from the building (outside) whose installation system is being earthed.

2. The earth wire should be of same material as that of earth electrode used.

3. The minimum sectional area of earth lead wired should not be less than 0.02 sq. inch and not more than 0.1 sq.inch.

4. As a general rule, the size of earth conductor should not be less than half of the section of the line conductor.

5. The earth wire should be taken through G.I pipe of 1mm diameter for at least 32cm length above and below ground surface to the earth electrode to safeguard against mechanical wear and tear.

6. For effective earthing, loose earth and coal salt mixture should be filled around the earth electrode .

7. All the joints in the earth wire should be firmly done with nuts and bolts of the same material as of earth wire.