HRC Fuse
HRC Fuse
(OP)
Hi,
How do we decide, if need a HRC fuse for a particular application. I spoke to one of the ferraz shawmut application engineer and he advised me that all of their fuses are HRC. Is there any other type also?
Thanks
How do we decide, if need a HRC fuse for a particular application. I spoke to one of the ferraz shawmut application engineer and he advised me that all of their fuses are HRC. Is there any other type also?
Thanks






RE: HRC Fuse
Selection of a fuse for 1000 KVA, 15.5 KV . The FLA is 37 Amp. Cutler Hammer 40 C was suggested but no reasoning given. I am sure, you guys could advise, what is the criteria for selection of fuse for transformer protection, I beleive overload of transformer is also considered.
Please advise me, if 40 Amp selection is fine.
Thanks
RE: HRC Fuse
RE: HRC Fuse
That means my so called "Intermediate engineer" is not right. What options do I have.
I make it 45 or you could advise me a transformer fusing protection philospohy. I read that it has to do with the transfomer over load chr. also .This bothers me that how to get in to the Over Load thing. Please give me few tips, where to look or how to make a decision. I think that will be helpful.
Thanks
RE: HRC Fuse
RE: HRC Fuse
RE: HRC Fuse
RE: HRC Fuse
Here is the SLF
ht
The fuse I selected is 50 amp from Ferraz Shawmut. All of their fuses are current limiting(General Purpose= Current Limiting + Over Load).
The transformer damage curve should be on the right hand side of the fuse curve. The problem is that for primary fault current it is fine, but when I want to go for a single line to ground fault on secondary. The damage curve shifs to the right of fuse curve. Could you please advise me, how can I satisfy both conditions.The fauly that occurs before the secondary protection and the secondary terminals of transformer.
Thanks
RE: HRC Fuse
old field guy
RE: HRC Fuse
IEEE Buff Book (std 242) is proper reading, so is S & C 's publication for transformer fuse selection.
For tighter protection E rated fuse are selected closer to FLA rating of the transformer, but not more than 125% of the FLA. (remember E rating is not same as regular ampere rating). Also people make distinciton between normal rating and fan cooled ratings.
RE: HRC Fuse
RE: HRC Fuse
RE: HRC Fuse
I recall reading this thread, I guess I should have remembered that. Could you advise me, I always come across
E type fuse. Why cannot we use K type or T Type fuse. I beleive K type is a fast acting fuse. Could you advise me in what situation I would use a k type fuse.
Thanks
RE: HRC Fuse
Also type of fuse holders makes the difference.
Refer to applicaiton notes of the manufactures.
RE: HRC Fuse
The best transformer protection for through faults (using a fuse) is generally an expulsion-type power fuse such as S&C SM type. Current-limiting fuses have very steep curves that generally don't coordinate well with anything else.
RE: HRC Fuse