This is the current which may be applied for time $\tau$ so that the conductor temperature at the end of the period of emergency loading reaches $\theta_{max}$.

The method only holds for values of $I_2 \leq 2.5 I_R$

Symbol
$I_{2}$
Unit
A
Formulae
$I_{R} \sqrt{\frac{\Delta \theta_{R_{\infty}} \left(- \frac{R_{1} h_{1}^{2}}{R_{max}} + 1\right)}{\Delta \theta_{t}} + \frac{R_{1} h_{1}^{2}}{R_{max}}}$
Related
$\Delta \theta_{R_{\infty}}$
$\Delta \theta_{t}$
$I_{R}$