DC Short-Circuit Current

Steady-state DC fault current from source resistance and cable, with L/R time constant, peak current and Joule integral (IEC 61660 simplified).

Inputs

System voltage U V

Source resistance R_s mΩ

Conductor material —

Cable length m

Cross-section A mm²

Loop inductance L µH

Peak observe time ms

Protection opening time ms

Results

Note — Steady-state model with a single L/R time constant (IEC 61660 simplification). Real batteries/rectifiers show higher peaks and a current-dependent source resistance. Select breakers/fuses for the calculated peak and I²t, and confirm against the DC network study and a certified engineer.