What IEEE80 Split Factor Curve to Use 1

[bwen08]

Hello,

Some info is in order first I suppose. I have a substation, fed via a 34.5kV (3 wire) line. Transformer is 34.5/7.2kV Delta/Gnd-Wye. The fault current is 2kA on the 34.5kV side. Rg=2.8ohms This sub is also tied to the 34.5kV source sub via two 7.2kV (4 wire) distribution lines.

Now I get lost at determining which IEEE80 Appendix C split current curve to use here. I don't see much in any searches on this subject. Would I use the curves for 100% remote source and 0 transmission lines and 2 feeders?

Thank you,

 

[eamonkerrigan]

Brian,
I run into this issue quite a lot. You are correct to use zero transmission lines and 2 feeders. Even for a HV fault, the feeder nuetrals will help.

You should also consider a low side fault outside the substation. I've seen a few cases where this is actually worst case. Depends on how much you want to dive in.