Earthing Cable Sizing May 2026

[ S = \frac\sqrtI^2 \times tk ]

[ A_mm^2 = I \times \sqrt\fract\Delta T \times k ] earthing cable sizing

Where ( k ) = 226 for Cu (annealed, 40°C to 250°C). Simplified: [ A_mm^2 = I \times \sqrtt \times 0.143 \quad (\textfor Cu, 1–3s) ] Most accurate for fault current withstand. From IEC 60364-5-54 : [ S = \frac\sqrtI^2 \times tk ] [