# Equivalent depth of earth return path

Definition according to Cigré guide 531 chapter 4.2.3.3. The equivalent depth of the earth return path of a 50 Hz system with an electric soil resistivity of 100 $\Omega$.m is about 930 m.

Symbol
$L_{earth}$
Unit
p.u.
Formulae
$\frac{2 e^{0.5}}{\gamma_{bessel} \sqrt{\frac{\mu_{0} \omega}{\rho_{earth}}}}$
Related
$\gamma_{bessel}$
$\mu_{0}$
$\omega$
$\rho_{earth}$
Used in
$a_{m}$
$X_{c}$