I assume they gave you 3 ph values and you have a single ph service?
what are the values? Mva, A, etc
you can convert them to a single ph equivilent
it is a 3PH service but SKM has required inputs for both 3PH contribution and 1PH contribution.
The utility should have provided you with the SLG fault value as well. If the service connects into a delta-wye bank and you are performing the study just on the wye side then model your xfmr and its impedances and then just use the same value for 1PH as your 3PH value in SKM.
The service is fed from an underground network in an urban area. This particular utility does not provide any of the transformer information because of this, they only provide the 3PH available current with X/R. Based on what you said if the 3PH value is 192kA and X/R is 2.45 I can just use the same numbers for 1PH?
You can use the three phase values for the single line to ground fault duty, but it will be much higher than the actual. The single phase fault will range from about 5% to as much as 60% of the three phase depending on where in the LTN grid you are located in. Based on the 192 kA with the X/R of 2.45, a reasonable value would be aboout 15 MVA, X/R of 1.6 for the single phase. This is based on one of my 208Y/120 Volt LTN locations with about the same 70 MVA three phase fault level.
Hope this helps.
did you base the fault mva of 70 on 120/208?