Hello please can anyone refer me to the first principle formula I can use to calculate the loop impedance and fault currents at LV cutouts?, at the point of use, e.g. in the building. The source information is known.
There are a lot of publications for short-circuit calculation as IEEE 551/2006 ,Schneider Cahier technique no. 158.
IEEE 80/2013, GE Application Information Short-Circuit Current Calculations, IEC 60909-0 and more other.
I tried to calculate the fault current as a continuation of the later post attached here.