Mean distance between the phases

This is the geometric mean distance (GMD) between phases.

Symbol
$a_{m}$
Unit
mm
Formulae
$L_{earth}$single-phase system
$s_{c}$two-phase system
$\left(a_{12} a_{23} a_{31}\right)^{0.333333333333333}$three-phase system
Related
$a_{12}$
Used in
$H_{s}$
$X_{c}$
$X_{S1}$
Reactance section 1 [$\Omega$/m]
$X_{S2}$
Reactance section 2 [$\Omega$/m]
$X_{S3}$
Reactance section 3 [$\Omega$/m]