Cable Short-Circuit Thermal Stability

Minimum conductor section from k²S² ≥ I²t for the protective clearing time (IEC 60364-5-54 / IEC 949).

Inputs

Fault current I_k (rms) A

Protective clearing time s

Insulation factor k A·√s/mm²

Actual conductor section mm²

Results

Note — k depends on insulation and initial temperature: PVC ≈ 115, XLPE/EPR ≈ 143/120 (A·√s/mm²). The check uses rms fault current and the protective clearing time; for adiabatic, short-duration faults only. Confirm against IEC 60364-5-54 tables and the cable maker's data.