Element B of equivalent thermal circuit

In the case of cables in air, the transient temperature rise of conductor above outer surface is obtained by replacing $T_B$ by $(T_B+T_C)$.

Symbol
$T_B$
Unit
K.m/W
Formulae
 $q_2 T_2+q_3 \left(T_3+T_{4i}\right)+q_4 T_{4ii}$ long-term transients $\frac{T_1}{2}+q_2 T_2+q_3 \left(T_3+T_{4i}\right)+q_4 T_{4ii}$ short-term transients $T_B+T_C$ cables in air
Related
$T_1$
$T_2$
$T_{4i}$
$T_{4ii}$
$T_A$
$T_C$
Used in
$N_0$
$Q_{B,ab}$
$Q_{B,d}$
$Q_{B,f}$
$Q_{B,i}$
$Q_{B,j}$
$Q_{B,s}$
$T_{a0}$
$T_{b0}$