1. Stabilize circuit potential with respect to ground and limit the overall potential rise.
2. Protect life and property from over-voltage.
3. Provide low impedance path to fault currents to ensure prompt and consistent operation of protective devices during ground faults.
4. Keep maximum voltage gradient along the surface inside and around the plant site within safe limits during ground faults.
While carrying out the earthing calculation, we check the following :
a. Calculated step potential is below the tolerable value.
b. Calculated touch potential is below the tolerable value.
c. Ground system resistance is below 1 ohm.
d. Ground potential rise is limited to 5kV or so.
We can deliver earthing calculations and layout drawings with BOQ as per IEEE 80 or CBIP manual or IS 3043.