fault level?

Question

what is the fault level in the HT 11 kv line how to calculate

Answer 1

I would need a bit more information.
What kind of fault? Earth fault or phase to phase fault (its different)
Where are you expecting the fault to occure - the further you are from the transformer the more it varies
What kind of line are you using?

You can calculate it from tables with the cables characteristics (Resistance and reactance), the distance and transformer characteristics (its impedance)

Give us a bit more to work on

Answer 2

Fault level is the maximum amount of current you would expect if a fault occurs. Calculating fault levels is fairly complex and you need the fault levels which are supplied by the Distribution company. Unless you are very close to a major Substation it will probably less then 200MVA