2LG fault from utility and ETAP doesn't match?!
2LG fault from utility and ETAP doesn't match?!
(OP)
Guys,
for a 2LG fault in phase A and B, fault current flowing to the ground should be calculated as:
Ifground=IfA+IfB.
I have IfA and IfB separately from utility but, summing them up, gives a (smaller) number which is not matching ETAP.
Is this because ETAP only gets single and 3phase short circuit parameters for utility and its 2LG current is not correct?
Or, may be there is something that I am missing here?
for a 2LG fault in phase A and B, fault current flowing to the ground should be calculated as:
Ifground=IfA+IfB.
I have IfA and IfB separately from utility but, summing them up, gives a (smaller) number which is not matching ETAP.
Is this because ETAP only gets single and 3phase short circuit parameters for utility and its 2LG current is not correct?
Or, may be there is something that I am missing here?






RE: 2LG fault from utility and ETAP doesn't match?!
For 2LG faults ETAP report shows the largest current among phases (not the current going to the ground).
This is important for grounding grid design because, we should know Max(1LG and 2LG).
RE: 2LG fault from utility and ETAP doesn't match?!
ETAP calculations-if Bus 4 data are the results-are not based on these impedances, in my opinion.