Impact Of Fuse Blowing Protection Scheme On Live Line Activity
Impact Of Fuse Blowing Protection Scheme On Live Line Activity
(OP)
I am looking to ask our protection people to revised some of the protection scheme currently employed by our utility. The scheme used currently is the fuse saving scheme. To improve MAIFI I am looking to employ the fuse blowing scheme on some feeders. What is the impact if any of this scheme on live line work. Is there any utility experiences where this is concern?
Off the bat one can argue that when the recloser is in the non-auto reclose mode to facilitate live line work if there is any mis-hap then the recloser will operate instantaneously on the fuse saving scheme than against a time delayed operation on the fuse blowing scheme. I believe that this is some what of a pseudo-protection. Any comment?
Off the bat one can argue that when the recloser is in the non-auto reclose mode to facilitate live line work if there is any mis-hap then the recloser will operate instantaneously on the fuse saving scheme than against a time delayed operation on the fuse blowing scheme. I believe that this is some what of a pseudo-protection. Any comment?






RE: Impact Of Fuse Blowing Protection Scheme On Live Line Activity
RE: Impact Of Fuse Blowing Protection Scheme On Live Line Activity
RE: Impact Of Fuse Blowing Protection Scheme On Live Line Activity
RE: Impact Of Fuse Blowing Protection Scheme On Live Line Activity
RE: Impact Of Fuse Blowing Protection Scheme On Live Line Activity
RE: Impact Of Fuse Blowing Protection Scheme On Live Line Activity
RE: Impact Of Fuse Blowing Protection Scheme On Live Line Activity
RE: Impact Of Fuse Blowing Protection Scheme On Live Line Activity
RE: Impact Of Fuse Blowing Protection Scheme On Live Line Activity
Form 4C is capable of doing this. There's an alternate minimum trip and you can desactivate reclosing with switch inside the control panel, so i'm pretty sure that form 6 will do it.
Utility were i am do this kind of stuff often when people are working on line. They desactivate the reclosing option and put a very fast trip curve.
RE: Impact Of Fuse Blowing Protection Scheme On Live Line Activity
Yes the Form 6 basically does this automagically. When Hot Line Tag is selected it will go to one-shot and switch the protection to the "Hot Line Tag" definite time delay which can be set as low as you want. Actually it shifts to the composite curve of Hot Line Tag Definite Time and TCC1 curve - using the faster of the two for any current. So you can set a specific definite time delay for Hot Line tag condition, based on the minimum pickup settings. These can all be different for Phase and Ground.
If that doesn't float your boat, you can set up an alternate protection group, activated by the Hot Line Tag toggle switch, I believe.
I think the Form 4C can do something similar.
RE: Impact Of Fuse Blowing Protection Scheme On Live Line Activity
RE: Impact Of Fuse Blowing Protection Scheme On Live Line Activity