Factor $F$ armour losses

The addition of steel tape armour increases the eddy-current loss in the sheath. The values for $\lambda_{12}$ given in IEC 60287-1-1, clause 2.3.7 and 2.3.8 should be multiplied by this factor.

We consider this factor only for steel tape armour. However, the procedure given in the paper 'Effective assessment of electric power losses in three-core XLPE cables' by Ander Madariaga et al., dated 2013, applies this factor also for cables with steel wire armour.

Symbol

$F_{ar}$

Formulas

$\left(1+\frac{1\left(\frac{d_{sh}}{d_{ar}}\right)^2}{1+\frac{d_{ar}}{\mu_s \delta_{ar}}}\right)^2$

Related

$d_{ar}$

Mean diameter armour [mm]

$d_{sh}$

Mean diameter sheath [mm]

$\delta_{ar}$

Equivalent thickness of armour [mm]

$\lambda_{12}$