With crossing heat sources, a temperature rise of $\Delta\theta_{0x}$ applies at the hottest point.
$\theta_c-T_1 \left(W_c+\frac{W_d}{2}\right)+n_{ph} T_2 \left(W_c \left(1+\lambda_1\right)+W_d\right)+n_{ph} T_3 \left(W_I+W_d\right)$ | Cables |
$\theta_{hsf}-W_{hs} T_{hs}$ | Heat sources |
$\theta_a+\Delta \theta_s$ | PAC/GIL in air |
$\theta_a+v_4 \Delta \theta_p+\left(1-v_4\right) \Delta \theta_x+W_{tot} v_4 T_{4\mu}$ | PAC/GIL buried without duct |
$\theta_{di}+T_{4i} n_{cc} W_{tot}$ | PAC/GIL with duct |
$\theta_{at}+\Delta \theta_s$ | PAC/GIL in trough |
$\theta_t+T_{4iii} W_{tot}$ | PAC/GIL in channel (Heinhold) |