What causes the difference between maximum and minimum fault values for the short circuit analysis?
The difference between maximum and minimum fault values are caused by a number of factors. The source impedance elements which are used at the supply point to your system let you specify maximum and minimum source impedances. The maximum source impedance applies to the minimum fault currents, and vice versa. Maximum fault current levels are reported for the case where motors and generators are assumed attached to the system. Minimum fault current levels assume that generation and large motors are not currently attached. If using the IEC 60909 option, fault currents are not reported for the nominal voltage of the system. Instead they are reported for a prescribed upper and lower voltage (e.g. 110% and 100% for medium voltage). The higher voltage range is applied for the maximum fault level, and the lower voltage range is applied for the minimum fault level. 4) If using the IEC 60909 option, a higher conductor resistance is used to compute the minimum fault currents. This represents the
