fault calculation 1

[kvkev]

Is it true to say that given the 3 phase short circuit fault current at a certain point in a system, that a fault between two phases only will produce 0.865 times the 3 phase current value in those two phases ?

 

[230842]

It is fairley true when fault is located far enough from a generator. In other terms, when impedances for positive and negative sequences are equal, then the statement is right (.866 instead .865, (sqrt3)/2) Julian

 

[kvkev]

Many Thanks Julian,

kvkev

 

[jbartos]

Comment: The above postings may need a little clarification, e.g.
Iline-line = [(sqrt3)/2] x Ithree-phase = 0.866 x Ithree-phase
This can obviously be further elaborated on.