Factor $F_e$ for eddy-current losses

Single core cables with Milliken conductors and solid bonding:
Where the conductors are subject to a reduced proximity effect, as with Milliken conductors, the eddy-current loss factor cannot be ignored, but shall be optained by multiplying the value of the eddy-current loss factor for single-core cables bonded at single point for the same cable configuration by the factor $F_e$.

Two- and three-core cables with steel tape armour:
The addition of steel tape armour increases the eddy-current loss in the sheath. The values for the eddy-current loss factor shall be multiplied by the factor $F_e$ if the cable has steel-tape armour.

Symbol
$F_{e}$
Formulae
$\frac{4 M_{e}^{2} N_{e}^{2} + \left(M_{e} + N_{e}\right)^{2}}{\left(4 M_{e}^{2} + 4\right) \left(N_{e}^{2} + 1\right)}$$n_{c} \leq 1$
$\left(1 + \frac{d_{s}^{2}}{d_{a}^{2} \left(\frac{d_{a} \delta _{ar}}{\mu_{s}} + 1\right)}\right)^{2}$$n_{c} > 1$
Related
$d_{a}$
Used in
$\lambda_{1e}$