Mutual heating coefficient

Mutual heating substitution coefficient for a group of equally loaded buried cables.

There are (q-1) terms considered in the product, with the term $d_{pp1}/d_{pp2}$ excluded. q is the number of non-touching cables within the same cable system.

For cables in a multi-layer backfill and for transient simulations, $F_{mh}=1$ with the mutual heating considered in the factor $\Delta\theta_p$ instead.

$\displaystyle \prod_{k=1}^{q} \frac{d_{pk1}}{d_{pk2}}$
IEC standard 60287-2-1 Ed. 2.0 (2015) Figure 1