Cableizer
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Emergency load current

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 $I_2\leq2.5I_R$

Symbol
$I_{em}$
Unit
A
Formulae
$I_R \sqrt{\frac{{h_{em}}^2 R_{ss}}{R_{max}}+\frac{1-{h_{em}}^2 \frac{R_{ss}}{R_{max}}}{\frac{\Delta \theta_{c,t}}{\Delta \theta_{R,\infty}}}}$
Related
$\Delta \theta_{c,t}$
Transient temperature rise of conductor [K]
$\Delta \theta_{R,\infty}$
Maximum permissible conductor temperature rise [°C]
$h_{em}$
Factor $h$ for emergency load
$I_R$
Transient conductor current [A]
$R_{max}$
Resistance of conductor at emergency rating [$\Omega$/m]
$R_{ss}$
Resistance of conductor before emergency rating [$\Omega$/m]
$\theta_{max}$
Temperature of conductor at end of emergency loading [°C]