I have been calculation ground grid system by ETEP 4.0.0 version Given:Area 90*68mm^2
surface material is crushed rock;10 cm
top layer 100 ohm/m
low layer 20ohm/m
fault current 31.5 kA,X=6
fault duration time 1 sec
grid current factor 100%
conductor is commercial Hard-Drawn
Rods are copper-clad...