Mv: Cable Sizing

[ \Delta V \approx \sqrt{3} \cdot I \cdot L \cdot (R \cos\phi + X \sin\phi) ]

[ A_{min} = \frac{I_{sc} \sqrt{t_{sc}}}{k} ] mv cable sizing

If the required load exceeds this corrected value, the next larger conductor cross-section (e.g., from 95 mm² to 120 mm² Cu) is selected. MV cables must survive fault currents until protection operates. Two criteria apply: a) Thermal Short-Circuit Rating During a fault (e.g., 25 kA for 0.5 sec), the conductor heats adiabatically. The minimum cross-section is: [ \Delta V \approx \sqrt{3} \cdot I \cdot

[ I_{corrected} = I_{base_table} \times k_t \times k_s \times k_g ] the next larger conductor cross-section (e.g.

[ I_b = \frac{S}{\sqrt{3} \cdot V_{LL}} ]