Siemens 7PG21 Solkor Rf - Page 35

7PG21 Solkor Rf Applications Guide
©2010 Siemens Protection Devices Limited Chapter 3 Page 15 of 15
Z
F
= 0.8309 + j3.9854 ohms
22
XRZ +=
22
9854.38309.0 +=Z
Z
F
= 4.071 ohms
Through Fault Current =
4.68kA
4.071
19.05x10
I
3
F
==
Through fault current = 4.68kA compared to 17.5kA Busbar fault current due to the effect of the line impedance.
19.05kV
Zs
17.5kA
Z
4.68kA
L