This is the transient temperature rise of conductor above ambient temperature.

After calculating separately the two partial transients and the conductor to cable surface attainment factor the total transient rise above ambient temperature is obtained

.

Symbol
$\Delta \theta_{\mathrm{t}}$
Unit
K
Formulae
$\Delta \theta_{\mathrm{c_{\mathrm{t}}}}$cables in air
$\Delta \theta_{\mathrm{c_{\mathrm{t}}}} + \Delta \theta_{\mathrm{e_{\mathrm{t}}}} \alpha_{\mathrm{t}} + \Delta \theta_{\mathrm{p}} \alpha_{\mathrm{t}}$buried cables
Related
$\alpha_{\mathrm{t}}$
$\Delta \theta_{\mathrm{c_{\mathrm{t}}}}$
$\Delta \theta_{\mathrm{e_{\mathrm{t}}}}$
$\Delta \theta_{\mathrm{p}}$
$\Delta \theta_{\mathrm{t_{\mathrm{\infty}}}}$
Used in
$\Delta \theta_{\mathrm{a_{\mathrm{t}}}}$