Cross-sectional area of filler

Symbol
$A_f$
Unit
mm$^2$
Formulae
$0$Single-core cables
$\pi \left(\frac{D_f}{2}\right)^2-2\pi \left(\frac{D_f}{2}-t_f\right)^2$Two-core cables
$\pi \left(\frac{D_f}{2}\right)^2-\left(\sqrt{3}-\frac{3}{2}\right)^2 \left(D_f-2t_f\right)^2 \left(\frac{5\pi}{2}+\sqrt{3}\right)$Three-core cables
$\pi \left(\frac{D_f}{2}\right)^2-\pi \left(\frac{D_f}{2}-t_f\right)^2$sector-shaped multi-core cables
Used in