In Korea, where most of the sites are narrow in space and their earth resistivity is relatively high, the spaces between grounding conductors are likely to be designed narrow in order to lower ground resistance and dangerous voltage below to the permitted safety values. In addition, ground nets are in the shape of square or rectangle depending on the location and size of the facilities and ground contact area, and inner conductors are laid out in grids like the pattern of nets. Nevertheless, with the existing designs, the marginal voltage for safety gets higher as the area is extended further outside, in comparison with that of inner mesh grounding, thus causing much difficulty maintaining them equipotential, and there exist limits in the burial, grounding grid design considering the dangerous voltage of muti-layered model in the constrained sites, was studied.