Loss factor of armour

The formulae express the power loss occurring in metallic armour, reinforcement of steel pipes of a cable in terms of an increment $\lambda_2$ of the power loss in all conductors. The IEC standard has formulae for three distinctive cases: Non-magnetic armour or reinforcement, Magnetic armour or reinforcement, and losses in steel pipes.

To be noted:

Symbol
$\lambda_{2}$
Formulae
$\frac{R_{s} \lambda_{1}}{R_{A} + R_{s}}$non-magnetic armour
$\frac{R_{s} W_{sA}}{W_{c} \left(R_{A} + R_{s}\right)}$magnetic armour, multiple single-core cable
$\frac{9.13614362192894 \cdot 10^{-9} A_{a} \omega \left(r_{c} + 0.675675675675676 t\right)^{2}}{R_{c} \left(A_{a} + 0.0104493207941484 d_{a}^{2}\right)^{2}} + \frac{6.2 \cdot 10^{-15} \omega^{2}}{R_{A} R_{c}}$magnetic armour, two-core cable
$\frac{1.64 R_{A} s_{c}^{2}}{R_{c} d_{a}^{2} \left(\frac{7672900000000.0 R_{A}^{2}}{\omega^{2}} + 1\right)}$magnetic steel wire armour, three-core cable, round conductors
$\frac{0.358 R_{A} d_{c}^{2}}{R_{c} d_{a}^{2} \left(\frac{7672900000000.0 R_{A}^{2}}{\omega^{2}} + 1\right)}$magnetic steel wire armour, three-core cable, sector-shaped conductors
$\frac{4.0 \cdot 10^{-11} f^{2} s_{c}^{2} \left(0.225 \delta _{ar} + \frac{1}{\delta _{ar}}\right)}{R_{c} d_{a} \left(\frac{d_{a}}{\delta _{ar} \mu_{s}} + 1\right)^{2}}$magnetic steel tape armour, three-core cable
$\lambda_{2} \left(- \frac{0.666666666666667 R_{c} \lambda_{1cb}}{R_{s}} + 1\right)$magnetic armour, three-core cable, individual screen/sheath
$\frac{R_{A} W_{A}}{W_{c}}$magnetic armour but without screen/sheath
$0$otherwise
Related
$A_{a}$
$\omega$
$R_{c}$
$W_{A}$
$W_{c}$
Used in
$f_{SHF}$
$\theta_{c_{z}}$
$W_{A}$
$Z_{pos}$