Fault detection of electrical equipment by rapid calculation of the magnetic field from single-circuit twisted three-phase cables

This paper proposes a very simple analytical formula for the magnetic field arising from single-circuit twisted three-phase cables as a tool to diagnose faults. Indeed, in the presence of cable faults the magnetic field around these cables increases dramatically. Then, by calculating the field with the formula using the current measured on one phase and by comparing the calculated and the measured field, one gets a direct indication of failure if the latter field is much greater than the former.