Short Circuit Rating
Short Circuit Rating
(OP)
Hi all,
I saw the short circuit rating of a distribution system as following
1. for 27.6/16.0 kV 16kA
2. for 13.8/8.0 kV 34kA
3. for 2.4/4.16kV 56kA
Why short circuit rating is higher when system voltage is small compare to higher system voltage ?
Is not higher short circuit rating in higher voltage system ?
I will appreciate for reply.






RE: Short Circuit Rating
Example: 10 MVA trafo; %Z = 5.79% or 0.0579 pu. Vs1 = 2400; and Vs2 = 4160:
Isc1 = 10,000/(1.732 X 2400 X 0.0579) = 41.5 kA.
But Isc2= 10,000/(1.732 X 4160 X 0.0579) = 23.97 kA.