Switchboard fault rating

[Indy]

Hi,
I have a query in relation to MV fault levels for an 11kv switch board. How is the fault rating (x kA for x seconds) calculated from the following information:

3 phase fault
Line to ground fault
Line to line fault
Line to line to found fault.

For each of these scenarios we have
I”k
Ip
Ik

And we also have Ib for all scenarios except 3 phase fault.

Thank you.