Earthing Cable | Sizing

A cable sized perfectly for thermal withstand may still fail if it is too thin to withstand physical stress.

However, engineers must verify this rule using the adiabatic equation in scenarios with high fault currents or slow-acting protection devices, as the standard rule may not always suffice for thermal withstand. earthing cable sizing

According to the IEC 60364-1 standard, the minimum earthing cable size required for a fault current of 10 kA and a fault duration of 1 second is 50 mm². Therefore, we would select a earthing cable with a cross-sectional area of at least 50 mm². A cable sized perfectly for thermal withstand may

A = (10,000 A × 1 s) / (226 × 100 Ωm) ≈ 44 mm² earthing cable sizing