Cable Sizing Formula Guide

[ V_d = \sqrt3 \times L \times I \times (R_ac \cos\phi + X \sin\phi) ]

Correction factors: ( k_t ) (40°C PVC) = 0.87 ( k_g ) (single circuit) = 1.0 ( k_s ) (air) = 1.0 cable sizing formula

[ I_req = 84.9 / 0.87 \approx 97.6 \text A ] [ V_d = \sqrt3 \times L \times I

Voltage drop (use R=0.87 Ω/km, X=0.08 Ω/km for 25 mm²): [ V_d = \sqrt3 \times 0.1 \times 84.9 \times (0.87\times0.85 + 0.08\times0.526) \approx 11.8 \text V ] % drop = ( 11.8 / 400 \times 100 = 2.95% ) → OK (<5%). cable sizing formula

[ A_min = \fracI_sc \times \sqrttk ]