Iec 60364 Cable Sizing Voltage Drop Formula [2021] File

The standard voltage drop formula for AC circuits is:

[ \Delta U = \sqrt3 \cdot I_b \cdot L \cdot (R \cos\phi + X \sin\phi) \quad \text(for 3-phase) ] iec 60364 cable sizing voltage drop formula

Example: A 3-phase 400V circuit, 100m, 50A, cosφ=0.8, using 16mm² copper (say ~2.8 mV/A/m): [ \Delta U = 50 \cdot 100 \cdot 2.8 / 1000 = 14 \text V ] Relative drop = (14 / 400 = 3.5%). IEC 60364 requires (R) be calculated at the conductor operating temperature , not at 20°C. The standard assumes maximum normal operating temperature (e.g., 70°C for PVC, 90°C for XLPE). The standard voltage drop formula for AC circuits