Short Circuit Matter

Dear ALL,

I am on reviewing vendor document, my system is 13.8 kV/0.48 Volt. 500 kVA,

vendor report for fault on busbar is:

3 Ph S/C =7.2 kA

Ph to G = 6.5 kA

Ph to Ph to G = 6.5 kA

after i run my ETAP, i find the same result.

BUT The Problem is my supervisor check it and tell me that S/c report is Wrong. he said Ph to Ph to Ground Fault is always bigger than other.

can anybody explain about this matter ?

tx...