Short-circuit thermal check (k for Cu/PVC = 115): [ A_min = \frac10,000 \times \sqrt0.1115 \approx 27.5 \text mm^2 ] 25 mm² is slightly below → upgrade to 35 mm² for fault withstand.
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%).
[ I_req = \fracI_loadk_t \times k_g \times k_s \times \dots ] Step 3: Select Cable from Tables Choose a cable where ( I_rated \ge I_req ). Step 4: Check Voltage Drop Voltage drop formula (single-phase): [ V_d = 2 \times L \times I \times (R_ac \cos\phi + X \sin\phi) ]
