Electrical Cable Size Calculations [repack] Jun 2026

10 kW, 3-phase, 400V, PF=0.86, L=120m, installation in conduit, 35°C ambient, 4 cables grouped, copper/PVC.

Common factors:

Copper (standard) vs. Aluminum (cheaper but requires larger sizes). Insulation Type: PVC (70°C max) vs. XLPE (90°C max). electrical cable size calculations

k₁ (35°C) = 0.94, k₂ (4 cables) = 0.70 ( I_\textmin = 16.8 / (0.94×0.70) = 25.5 A )

Would you like a downloadable or a table for AWG (US) sizes ? 10 kW, 3-phase, 400V, PF=0

Used for underground or outdoor runs where mechanical protection is needed.

4 mm² Cu in conduit = 28A → 4 mm² meets current. Insulation Type: PVC (70°C max) vs

[ VD = \frac2 \times L \times I \times (R \cos\phi + X \sin\phi)1000 \quad (\textvolts) ] Formula (three-phase): [ VD = \frac\sqrt3 \times L \times I \times (R \cos\phi + X \sin\phi)1000 ]