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View Full Version : Fuse Cutouts - Defective ??



stickstomper
08-09-2006, 06:24 PM
Does your company consider a fuse cut-out switch to be defective if the fuse blows and the fuse tube does not fall in to the open position ? We have been re-fusing dozens of them that the fuse has blown on and they do not open up. Does this cause problems other than not being able to see the fuse open ? Does it alter the time it takes the fuse to open the circuit ? We have replaced several fused transformers that were burned up by lightning and the fuse tubes were still in the closed position with a burned fuse link inside. Seems like they should be replaced to me. What do you think ???

Electriceel
08-09-2006, 08:01 PM
Seems this has been a problem also the last few years. Our people blame it on the fuse tube collecting moisture and expanding not allowing the fuse holder to properly drop down.
I believe it will be ABB now that says there tube holder is water resistant.
Cut-Out should be fine.
The only problems caused are the fact of not being able to see a dropped door when chasing line.

topgroove
08-09-2006, 08:01 PM
Happens all the time. I guess I've grown used to looking for the tiny piece of fuse link that hangs down from the closed cut-out. Its just one of those things that happen. I haven't seen it happen yet with the polymer type cut-outs but I'm sure its just a matter of time.

NU Limey
08-09-2006, 09:14 PM
There is no rhym or reason these occur. high resistant faults or sometimes what I call close strikes can cause it. A good trained eye can see these. wannabees patrolling ahead will say the fuse is closed when in reality its not.recently seen an SMD 20 door burn up because it didn`t open when a limb bounced off the three phases. that was exciting to watch until the circuit was dumped. They happen, never been set up. but always wear your PPE when throwing it in.