Thanks for the info, I guess my next question would be then do I even care about the X/R? It seems as if M multiplier for symmetrical = the asym factor, or am I way off?
I've got myself confused. I've got a utility with 3phase Isc=68.1MVA X/R=3.80218 going to a 3000kVA, 13.8kv/480V, 3phase, z=5.69%. Am I to calculate asymmetrical or symmetrical for sc?