Diameter below 1st armour

Symbol
$D_{2_{1}}$
Unit
mm
Formulae
$D_{oc} F_{x} + 2 t_{ab_{1}} + 2 t_{f}$multi-core cables with separate screen/sheath
$D_{oc} + 2 t_{ab_{1}}$otherwise
Related
$D_{oc}$
Used in
$A_{ab_{1}}$