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

• for buried configurations by simple addition of the cable and modified environmental partial transients;
• for cables in air by modification of the cable partial transient.
.

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
$\Delta \theta_{\mathrm{a_{\mathrm{t}}}}$