CI 2 # 44 (Old version) : Fault current

[RBsai]

I am using MVA method to calculate fault current and i got 8018 A but the CI solution is 8027 A. Could anyone please let me know if i am missing something :

Sg1 = 30 MVA/0.24 = 125 MVA,

SG2 = 20 MVA/0.24 = 83.33 MVA

Since the generators are in parallel, i added both MVAs = SG1+SG2 = 208.33 MVA

I fault = Stotal/(VLine * sqrt (3))

= 208.33 / (15*sqrt(3)) = 8018.7 Amperes

 

[EEpowerOK]

Looks correct, their answer says most nearly

 

[daw4888]

I am using MVA method to calculate fault current and i got 8018 A but the CI solution is 8027 A. Could anyone please let me know if i am missing something :

Sg1 = 30 MVA/0.24 = 125 MVA,

SG2 = 20 MVA/0.24 = 83.33 MVA

Since the generators are in parallel, i added both MVAs = SG1+SG2 = 208.33 MVA

I fault = Stotal/(VLine * sqrt (3))

= 208.33 / (15*sqrt(3)) = 8018.7 Amperes

You look good. It could easily be some rounding differences.

 

[RBsai]

Some of the options to NCEES questions are very close so want to make sure there are no numerical errors. Thanks for the sanity check.