How can we calculate the fault level of the distribution
system knowing the percentage impedance of transformer &
subsequent equipments.

Answer Posted / jigar shah

suppose transformer (11 KV/433) is of 1000 KVA & %
impedance is 4 .LT side Fault level can be calculated as
below :

KVA = 1.732 X V X I X Cos Phi - PF assumed : 0.95

LT Rated current (I) = (1000 * 1000)/(1.732*433*0.95)
= 1481 A

Fault current on LT side = FLC * 100/(% impedance)
= 1481 * 100/5
= 29.62 KA

Is This Answer Correct ?    44 Yes 54 No



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