What is the problem with having throat connections greater than 15kV on a transformer?
From C57.12.10-1997:
"9.6 Throat connection
A throat connection or connections may be provided for windings of 110 kV BIL (15 kV nominal system voltage) or less."
Say we have cables (two per phase) terminating at a bus, can the skirts of the cable termination kits ON THE SAME PHASE touch?
Would the voltage potential throughout the length of the termination on both cables be equal? Or would there be slight differences of potential between the two...
dpc,
Thank you for the response. You're correct, what I mean to protect is from a fault on a bus after the transformer and circuit breaker.
The %impedance does say OA, but there are two: 8333kVA and 9333kVA. Why not use the 9333kVA rating?
What is the interrupting current rating required for a circuit breaker to protect this transformer?
Single phase transformer:
OA, 55C: 8333 kVA
OA, 65C: 9333 kVA
FA, 55C: 10000 kVA
%Impedance: 10.2% (at 75C, OA Base)
Is it:
1. FLA = 8333kV / 5.04kV = 1653A; IC = 1653A/.102 = 16206A,
2. FLA...
