Total loss in shield and magnetic armour

The total loss in shield (screen$||$sheath) and magnetic armour is given acc. IEC 60287-1-1 chapter 2.4.2.1 and is used to calculate the loss factors $\lambda_1$ and $\lambda_2$ which may be assumed to be appoximately equal.

Symbol
$W_{sar}$
Unit
W/m
Formulae
${I_c}^2 R_e \frac{{B_2}^2+{B_1}^2+R_e B_2}{\left(R_e+B_2\right)^2+{B_1}^2}$