Bad NX solid blade?

[MI-Lineman]

Anybody ever see an underground solid blade go bad? Had X and Y blown at riser(4.8 80amp) with X phase cutout flashed over at top. Opened solids at 1st cabinet, changed cutout(no other flash over signs on pole?), closed both switches and held. I then noticed X phase switch in cabinet had flash signs and the bottom of the solid was burnt? Also the X phase solid blade itself seemed looser than the other 2 solids. THERE WERE NO OTHER SIGNS ON ANYTHING OF A PHASE TO PHASE FAULT to have opened Y phase? We changed the solid out with a new one and everything is still holding as of a week now?:)

[MI-Lineman]

OOO.K.......Anyone know what I'm talkin bout? Anyone at all?.....You know, solid blade with the slide or barrier to expose the conductive end of the blade....use your underground switch stick to slide open AFTER PLACING IT IN THE HOLDER!!!.....plastic ring on top....break if you slam to hard:eek:.....Ah never mind: it must be a first!

[T-Man]

We used NX fuses but I haven't seen a solid blade NX like you explain. I have seen fuse holders burn at the joint where the holder takes the fuse. I think that occurs because connection is corroded or somehow bent out of shape then the curent is not enough to take the fuse out and it eats up the loose connection. I could see this being a bigger problem on a solid because there would be more current available. NX is getting to be a bit out dated around here we have plenty with broke rings. . .a neat idea for snuffing the arc opening under load but not very strudy for long service. Have you got any pictures to post maybe it would help?

[T-Man]

I guess I have seen the switches just not often. here is the PDF on them.

http://www.nepsi.com/PDF%20Files/FUSE%20-%20NX%20WITH%20FUSE%20CLIPS.pdf

[Edge]

yeah man can see it... all solid blades need to be adjusted prior to being energized...

the exceptions would prolly be "cutout" style or "solid barrel" set ups.. but they are junk in my opinion...

if you hang a switch in the air you adjust it make sure it opens and closes properly... why not to the same with underground switches... I gotta tell you though I take it for granted that they are perfect from the factory... but this post made me think...

shit the switch pots are loaded unto a rig driven down the highway who knows ow many miles... then ff loaded with a digger or crane then reloaded later on to a trailer with a digger or crane... hauled out to the most fugged up location you could ever think of unless your an engineer... then set with a digger or crane...

then we hook 'em up...heat em up ...and go home...

all that bumpin and jarrin had to do something... and whose to say that the Mexican didn't get that ONE nut tight???

yeah I can see it failin.... just never have seen it in a cabinet....

I'll be checking my URD blades from now on though...

For what it's worth,

Edge

[MI-Lineman]

I guess I have seen the switches just not often. here is the PDF on them.

http://www.nepsi.com/PDF%20Files/FUSE%20-%20NX%20WITH%20FUSE%20CLIPS.pdf

Sorry for not gettin back soon....Off chasing whitetails(unsuccessfuly):mad:
I see you found the PDF on them, that's them. We still have a ton of them but I was just woundering if anyone else seen one go bad. It was in service along time, I think it just got hot and gave up and flashed over? I don't know.....I GUESS THAT'S WHY THEY CALL IT ELECTRICAL THEORY?

[thrasher]

It's been years since I worked at a Co-op that had the NX fuses and blades in thier livefront padmount transformers. However I can remember one or two flashover when the fuse in the center failed. The NX are supposed to be a non-expulsion type with no fumes released, but on a couple of occasions (very rare) we found the fibreglass tube split and vent marks on the shields. Our THEORY, and that all it was, was that in rare dead faults the housing of the fuse failed and vent conductive gases across the livefront energized parts. This caused a flash to occur in the cabinent. We could never prove it and it was so rare that basically we didn't worry over it.

[MI-Lineman]

It's been years since I worked at a Co-op that had the NX fuses and blades in thier livefront padmount transformers. However I can remember one or two flashover when the fuse in the center failed. The NX are supposed to be a non-expulsion type with no fumes released, but on a couple of occasions (very rare) we found the fibreglass tube split and vent marks on the shields. Our THEORY, and that all it was, was that in rare dead faults the housing of the fuse failed and vent conductive gases across the livefront energized parts. This caused a flash to occur in the cabinent. We could never prove it and it was so rare that basically we didn't worry over it.

That sounds possible to me? This was a solid blade though not a fuse.