Exploding fuses...

[BigClive]

While browsing for some spare 800A fuses for an industrial application I came across the section in the fuse catalogue for the high voltage fuses used in cutouts. The text seemed to imply that some had a small explosive charge in them to ensure that the fuse would break the current in a swift manner. Is this true?

I also noticed the price of them! I wonder how many of you know just how much that loud bang at the top of the pole just cost. :D

[topgroove]

none of the blown fuses I've replaced needed any help. I do remember a while back doing a live line demo at an air show where we packed the 25k fuses with gunpowder to make it more impressive. the first show in the morning we used a little too much powder and a little kid in the first row got hit by the resedue and started to cry... we were all horrified.he was allright though just a little shook up. the next show we used just a pinch in each fuse.

[theweber]

While browsing for some spare 800A fuses for an industrial application I came across the section in the fuse catalogue for the high voltage fuses used in cutouts. The text seemed to imply that some had a small explosive charge in them to ensure that the fuse would break the current in a swift manner. Is this true?

I also noticed the price of them! I wonder how many of you know just how much that loud bang at the top of the pole just cost. :D

The fuses with explosives are called sand fuse. Just as the name implies it is filled with sand, the explosive forces a nail out the end to about 1" ish. When you look up and see the nail it to let's you know it has done it's job.

[Edge]

The fuses with explosives are called sand fuse. Just as the name implies it is filled with sand, the explosive forces a nail out the end to about 1" ish. When you look up and see the nail it to let's you know it has done it's job.

yeppers those are the ones we usually use on our bulk feeders not as bad as you think though BC most of them have "baffles" built into them... especially the ones used in ? UG switches other wise the concussive force would prolly split the switch in half (sorta like tossing a m80 in to a dumpster half filled with water)... how ever the ones that don't have the silencer rings.... yeah you better believe you need to be on the end of a LONGGGGGG stick when closing in.... roflmao

Edge

hell or high water? we're lineman.... so that sounds easy....

[BigClive]

I do remember a while back doing a live line demo at an air show where we packed the 25k fuses with gunpowder to make it more impressive. the first show in the morning we used a little too much powder and a little kid in the first row got hit by the resedue and started to cry... we were all horrified.he was allright though just a little shook up. the next show we used just a pinch in each fuse.

That's the peril of pyro. Change the conditions slightly and a small bang turns into a large boom (with shrapnel).

For reference, the thing you guys want to scare members of the public safely is called a theatrical maroon. It's electrically detonated (about 1A at battery voltage) and creates a mutha of a boom with little to no shrapnel, particularly if used in a "bomb tank" (empty pole pig?)

You could also use "gerbs" for continuous showers of sparks or "robots" for a single large burst of sparks on cue.

So much handy pyro... You guys could make your audiences brown their pants at demo's. ;)

Here's the website of the primary supplier to the FX industry.
http://www.lemaitreltd.com/
In many instances you will probably not need a license to buy or use these effects. Just use sensible precautions when wiring them up and using them, since they can cause serious burns right up there with arc flash (mainly because they ARE metal loaded plasma explosions).

Here's the vid I did to go with a controller article for a UK electronics supply company.

http://www.youtube.com/watch?v=UKQutZbmUjc

Not that I should be encouraging you guys to blow stuff up... :rolleyes:

[Hemingray Insulators]

The fuses with explosives are called sand fuse. Just as the name implies it is filled with sand, the explosive forces a nail out the end to about 1" ish. When you look up and see the nail it to let's you know it has done it's job.


I seen a segment about those fuses on a show "how its made", they were pretty interesting i thought.........

[NU Limey]

S&C electric company makes a fuse, they call a `power fuse` for distribution, We use an SMD 20 on certain applications on our 34.5kv system. They are bigger than normal cutouts. each fuse is self contained. From what I have been told they contain some sort of a small explosive charge to help them blow. Do we like them? NO. They have a tendency to hang up when trying to open. We have complained about them for years. We now have some engineers that will listen and are now beginnging to replace them with standard cutouts. Check out their web site. S&C also has SMD 20s for substations, which are bigger.

[NU Limey]

In looking at some handling instructions for the SMD power fuses, there is no mention of any explosive agent inside. There are plenty of precautions of Do not drop, Do not throw and Do place hand on top of the fuse as the spring loaded pin may pop up and pierce your hand. The only other thing that may refer to explosive is a `current responsive section` in the fuse. Maybe when that spring lets go it sounds like a mini-blast.I still know we don`t like em.

[Squizzy]

I am positive some of the real big fuses they use over here have an explosive charge as one of my old instructors showed us all one. It had blown but you couldn't see much but they are worth some real big$$$.