BC... What CPope was trying to say was that a limitor fuse has a built in snuffer... Though some of them have become a little more hightech now... the origional limitor was simple... A Fuse running through a tube of sand...
When the fuse melts in two, the ARC begins... In a tube of sand, the heat of the arc immediatly turns the sand to glass... a glass insulator... effectivly snuffing the ARC limiting the wide open current durration. In the conventional fuse barrel, the arc continues untill the air is vaporized and there is nothing left to conduct the ARC. This small time frame of ARCing pulls a tremendeous current in its duration. When the air is vaporized, the air around the vacume comes back togather with a sort of clapping motion... resulting in a Boom as heard by the ear... Lighting does the same thing.
Anyhow, the fault current time is cut short by the limitor fuse, resulting in less heat stress on the components... xfmr bushings etc.
And now a bed time story for your marveling pleaure...
One Christmas night it was more frigid than Hillary in the White House... They had the amps cranked way up at the Sub Station because everything was overloaded... A 35KV Circuit operated and though it came back on... some of the lights on the circuit were still out... I was sent to investigate... I marveled at what I eventualy found... Two spans out of the Sub, C phase had burned off at a splice... The 600 wire hit the sidewalk energized... The sand in the concrete was boiled out by the ARC and formed a glass insulator... The Phase was sitting on top of the insulator hotter than Monica Lewinski in the Oval Office... The glass was non opaque, a lime green color and the phase was sort of in the middle of it(not unlike Monica in her green dress)... I almost bumped into it walking down the sidewalk and I about sh@t my pants like a Muslim and Swamp at the second comming... Anyhow this is an example of natures very own current limiting fuse... After I got them to drop the circuit out, I cut the wire on both sides of the Insulator and chipped it out of the concrete...
....If you want to see it, it now resides in a the trophy case at the Sugarland Service Center next to the picture of the Company Co-Ed Softball Champions for what ever year it was... of which yours truly was is in...
Last edited by CenterPointEX; 04-04-2008 at 08:47 AM.
2Do you not know that the saints will judge the world? And if you are to judge the world, are you not competent to judge trivial matters? 3Do you not know that we will judge angels? How much more the things of this life! 1Corinthians 6