Earthing arrangements

Vertically buried electrodes

\[R = \frac{\rho}{L} \]

· R: Earth electrode resistance, Ω

· ρ: Resistivity of the soil, Ω·m

· L: Length, m

Horizontally buried conductor

\[R = \frac{2 · \rho}{L} \]

· R: Earth electrode resistance, Ω

· ρ: Resistivity of the soil, Ω·m

· L: Length, m

Buried plates

\[R = \frac{0.8 · \rho}{L} \]

· R: Earth electrode resistance, Ω

· ρ: Resistivity of the soil, Ω·m

· L: Perimeter of the plate, m

Metallic pillar as earth electrodes

\[R = 0.366 · \frac{\rho}{L} · log_{10} · \frac{3 · L}{d} \]

· R: Earth electrode resistance, Ω

· L: Buried length of the pilla, m

· d: Diameter of the cylinder circumscribed to the pillar, m

· ρ: Resistivity of the soil, Ω·m

Total resistance

\[\frac{1}{R_{total}} = \displaystyle\sum_{i=1}^{n} \frac{1}{R_{i}} \]

· R_total: Total resistance of the electrodes, Ω

· R_i: Resistance of each electrode, Ω