Cable Size Calculation: Electrical

30 kW, 400V 3-phase, cosφ=0.85, L=150 m, ambient 35°C, XLPE cable in conduit with 3 other circuits.

Example (copper, 90°C thermosetting, 30°C ambient): electrical cable size calculation

Looking at a standard Copper/PVC table, a 4 mm² cable has a rating of roughly 32 Amps. Since $32 > 28.3$, 4 mm² is selected. 30 kW, 400V 3-phase, cosφ=0

The voltage drop should typically not exceed 3% for lighting circuits or 5% for power circuits. If the calculated drop is too high, you must select the next larger cable size. electrical cable size calculation

Where: