Cableizer ®

Equivalent diameter of screen and sheath

Equivalent diameter between screen and sheath.

Symbol
$d_s$
Unit
mm
Formulas
$\sqrt{\frac{{d_{sc}}^2+{d_{sh}}^2}{2}}$single-core cable or sheath and screen both being separate or common
$\sqrt{\frac{\left(F_x d_{sc}\right)^2+{d_{sh}}^2}{2}}$cable with separate screen and common sheath
$d_{sc}$screen but no sheath
$d_{sh}$sheath but no screen or CIGRE TB 880 Guidance Point 31
$\sqrt{\frac{\left(\frac{D_{ins}+D_{sc}}{2}\right)^2+\left(\frac{D_{sc}+D_{sw}}{2}\right)^2}{2}}$pipe-type cables with screen+skid wires
$D_{encl}-t_{encl}$PAC/GIL
Related
$D_{encl}$
Diameter enclosure (outer) [m]
$D_{ins}$
Diameter over insulation [mm]
$D_{sc}$
Diameter over screen [mm]
$d_{sc}$
Mean diameter screen [mm]
$d_{sh}$
Mean diameter sheath [mm]
$D_{sw}$
Diameter over skid wires [mm]
$F_x$
Geometrical distance factor for multi-core cables
$t_{encl}$
Thickness enclosure [m]
Used in
$d$
Geometric mean shield diameter [m]
$d_e$
Equivalent diameter of screen/sheath and armour [mm]
$GMD$
Geometric mean distance between phases of the same system [m]
$H_s$
Conductance sheath [H/m]
$r_s$
Mean radius shield [m]
$X_e$
Self reactance screen/sheath [$\Omega$/m]