We have Indoor LV substation area of 600sqmm. We need to derive the required no of earth pits to be placed.
The main earthing conductor is 120Sqmm cu, sleeved, soil resistivity is 100ohm/m, minimum earth rod size to be used is 25mm dia 1200mm long, required minimum earth resistance 1 ohm ...
Thanks Mr. RalphChristie,
My application is to limit the earth fault current. Actually my question is that why not we use NGR in LV or HV, why only in MV? Is there any Specific reason to select NGR/Solid earthing?