IEC-Guided LV 0.6/1 kV Copper Cable Sizing: ΔV and I²t

Abstract

We present an IEC-guided workflow to select, install, and verify low-voltage (0.6/1 kV) single-core Cu XLPE/PVC cables using manufacturer-verified parameters and standard equations for temperature-dependent resistance, three-phase voltage drop, and adiabatic short-circuit sizing. Inputs are taken from Nexans SDI datasheets (16, 120, 150 mm²) and cross-checked against Prysmian Table C4; device envelopes follow ABB/Eaton tripping assignments consistent with IEC/EN 60898-1 and IEC/EN 60947-2. We compute ΔV–length envelopes at 0.8·Iz (pf = 0.90, 400 V, 3φ), tabulate maximum permissible lengths for ΔV ≤ 4 %, and provide I_perm=kS/√t maps. A cross-vendor parity analysis contrasts ΔV computed with Nexans RAC at operating temperature plus trefoil reactance versus Prysmian R20 corrected to 80 °C plus Prysmian reactance, yielding close agreement (MAPE ≈ 2.68 %, RMSE ≈ 0.075 %-points, 95% CIs reported). A worked example demonstrates end-to-end selection and coordination with a named device class. The method is auditable against vendor data and IEC/IEEE/EN standards [1],[14].