Calculation of the earth resistance of the union of two and three rods by modified Schwarz equations and field tests

This report discloses the modification of the Schwarz equations presented in the IEEE 80-2013 standard, in order to calculate the ground resistance of two and three rods connected in line, and three rods connected in triangle. The implementation of these designs is carried out in several soils with different resistivity values, to proceed to measure the resistance of grounding and to check with the theoretical calculation.