Interrupting Rating for Medium Voltage Fuses
Interrupting Rating for Medium Voltage Fuses
(OP)
I have an application where I am tapping off isolated phase bus(13.8 kV) at the generator terminals with 15 kV cable to provide power to a step down power transformer(645 KVA 13,800/400 V). At this tap location, we have calculated a fault current of 83.7 kA symmetrical. I have been unable to find a medium voltage fuse that can handle this fault duty (highest found is 60 kA). Any help would be appreciated.






RE: Interrupting Rating for Medium Voltage Fuses
Check with GE and S&C.
RE: Interrupting Rating for Medium Voltage Fuses
a) What happen to the generator if you have phase-to-phase fault in the cable?
b) How far can the cable be tapped from the IPB to comply with the tapping rules of the NEC?
c) Is the primary protection on the high side of the GSU capable to protect the small new transformer?
d) Since 700 kVA transformers at 13.8kV/400 V is relatively easy to find as out of the self item, it is acceptable to take the risk of replace it if a fault happens?
RE: Interrupting Rating for Medium Voltage Fuses
But aside from that, I'd check with S&C and ask about their "Fusitor". I have seen these used for VT fuses with up to 80 kA of fault current, but they may not have a large enough size for your power transformer.
RE: Interrupting Rating for Medium Voltage Fuses
RE: Interrupting Rating for Medium Voltage Fuses
RE: Interrupting Rating for Medium Voltage Fuses
http://www.sibafuses.com/pdf/hhd.pdf
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