Self reactance of screen/sheath

The equation for a single phase with earth return is from the Cigré guide 531 chapter 4.2.3.5.

Symbol
$X_{s}$
Unit
$\Omega$/m
Formulae
$\frac{\mu_{0} \omega \ln{\left(\frac{2 s_{c}}{d_{e}} \right)}}{2 \pi}$default cable without transposition
$\frac{\mu_{0} \omega \ln{\left(\frac{2 a_{m}}{d_{e}} \right)}}{2 \pi}$default cable with regular transposition
$\frac{\mu_{0} \omega \ln{\left(\frac{2 s_{c}}{d_{encl} - t_{encl}} \right)}}{2 \pi}$GIL
$1.25 X_{s}$unknown variation of spacing between sheath bonding points
$\frac{X_{S1} a_{S1} + X_{S2} a_{S2} + X_{S3} a_{S3}}{a_{S1} + a_{S2} + a_{S3}}$known variation of spacing between sheath bonding points
$\frac{\mu_{0} \omega \ln{\left(\frac{2 L_{earth}}{d_{e}} \right)}}{2 \pi}$1 cable with earth return
$\mu_{0}$
$\omega$
$t_{encl}$
$X_{S1}$
Reactance section 1 [$\Omega$/m]
$X_{S2}$
Reactance section 2 [$\Omega$/m]
$X_{S3}$
Reactance section 3 [$\Omega$/m]
Used in
$\lambda_{1cb}$
$Z_{pos}$
$Z_{s}$