Short circuit hand calculation
Sequence networks are useful for analysis of unsymmetrical faults. A little hand calculation never hurt.A simple system is assumed as below.
![](\static\img\blog\cal1.jpg)
Three phase fault at the end of L4 can be calculated using the matrix method.
![](\static\img\blog\cal2.jpg)
Single phase fault at the end of L4 can be calculated using the equivalent impedances of the sequence networks .
![](\static\img\blog\cal3.jpg)