Electrical Cable Size Calculation __top__ Direct

Vd per km for 10 mm² copper (from table) ≈ 3.8 V/A/km (3-phase) Vd = 3.8 × 51 × 0.15 = %Vd = 29.1 / 400 = 7.3% – exceeds 5% limit → increase size .

Using simplified: Vd = (1.732 × 51 × 0.15 × 0.0175 × 1.2) / 10 = (0.278) / 10 = 0.0278 V per A per m? Let's recalc properly: electrical cable size calculation

Temp 35°C: factor 0.96 (XLPE) Grouping 4 circuits: factor 0.80 Required ampacity = 51 / (0.96 × 0.80) = 66.4 A Vd per km for 10 mm² copper (from table) ≈ 3

Example: Load = 50 A, ambient 45°C (correction factor 0.82 for 90°C insulation), 4 cables together (grouping 0.80) → 50 / (0.82 × 0.80) = Step 3: Select Initial Cable Size from Ampacity Table From standard tables (e.g., IEC 60364 or NEC Table 310.16), choose a cable with ampacity ≥ calculated value. 10 mm² → 72 A → meets 66

10 mm² → 72 A → meets 66.4 A requirement.

I = 30,000 / (√3 × 400 × 0.85) = 51 A

Try 16 mm²: Vd per km ≈ 2.4 V/A/km Vd = 2.4 × 51 × 0.15 = 18.4 V → 4.6% → .