Regarding Short Circuit MVA

Good guess, but most of us at CR4 have done our homework long before we showed up here, so we don't want to do it again...and the rules prohibit it. (Hint: what governs the relationship between the busses?) If you want more help, tell us what the post-fault voltages are at each bus.

OK, I'll say, " the relationship between ΔV1, ΔV2 & ΔV3".

Anything else you want us to say?

I'll just say, "do your own homework".

Also, if you have a short circuit, the fix is to lengthen it.

(Sometimes I scare myself with my own brilliance)

come on man, at least rephrase the question enough so it sounds like it's an actual problem you're working on in a Field application

"I was working at the local substation, when suddenly a a backhoe hit the 3-phase delta cables underground, that are connected to bus 2, shorting them all together. Because someone has borrowed our hot stick, I cannot measure the voltages, I must calculate them."

not bad

Er, so why do the circuit protective devices not operate, thereby lowering the voltages to zero?

that was part of the homework question