Bit confused, I was reading this in a book called modern wiring practices
Calculation minimum fault current 3P 3 wire.
Ipp = VL / 2zp
Ipp - phase / Phase PSSC
VL - Line voltage
2zp inpedance of one phase only
So using 400V
In the design guide its.
Ief = Cmin Uo / Zx + CrZd + Cr'Z1 +Cr"Z2 + Cr'"Zpen
So using 230V
EIDG tells us A fault across three phases is considered the worst case....
and we get Cmax Uo / Zx +Zd
Again voltage to earth is used.
But basically a bit unsure why 230V is used to calculate 3 phase fault current and not 400V
Any help really appreciated. Thanks