Formula — For Cable Size Calculation _verified_

$$ I_{rated} \ge I_{load} $$

A more accurate form for incorporates reactance ($X$): formula for cable size calculation

$$ I_{table} \ge \frac{I_{load}}{k_1 \times k_2 \times k_3 \times \dots} $$ $$ I_{rated} \ge I_{load} $$ A more accurate

$$ V_d = \frac{2 \times L \times I \times R_{dc}}{1000} \quad \text{(simplified)} $$ formula for cable size calculation

$$ A = \frac{2 \times \rho \times L \times I}{V_{drop_allowed}} $$

$$ V_d = \frac{2 \times L \times I \times (R \cos\phi + X \sin\phi)}{1000} $$

However, the rated ampacity ($I_{rated}$) of a cable depends on several correction factors. The practical formula for selecting a cable based on heating is: