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Blowing up a 5000 amp fuse

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  • #31
    Originally posted by lynnl View Post
    Yeah, of the 18:41, I skipped over the last 18:30.
    ...but still, I regret the time I wasted.
    I found the commentary interesting

    Comment


    • #32
      Originally posted by Arcane View Post


      I care because somebody might watch that and then, not knowing the dangers, attempt it and possibly seriously hurt themselves or worse yet, innocent bystanders.
      I appreciate your point of view about being safe. I really do.
      But you can't save the world.
      Do you appreciate my point of view?
      If you worried about all the dangerous stuff on youtube
      you don't have enough years in your life to do that.
      I think it is fighting a loosing battle to be cry safety about a youtube video.
      Again, just my opinion. You obviously feel differently and will continue on your quest.

      -D
      DZER

      Comment


      • #33
        Originally posted by RB211 View Post

        I found the commentary interesting
        Obviously. Or, at least I assume that's why you posted it. I meant no criticism of the fact the link was posted, rather just the length.

        The topic did look interesting to me; that's why I clicked on it. I might have found it interesting, but probably not 18+ minutes worth of interesting.
        Lynn (Huntsville, AL)

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        • #34
          I believe he works on high power radar from memory, some defence stuff at least, I certainly wouldn’t muck round with 1000amp Mercury arc rectifiers and such in what looks like my lounge, slightly insane imho, certainly gets your attention
          mark

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          • #35
            Why does the explosion look fake???

            Comment


            • #36
              He routinely does his experiments in the house on carpet,
              interesting to say the least. I fully predict this house burns
              down some day.

              -D
              DZER

              Comment


              • #37
                A waste of a very expensive fuse. The reason that the fuse is built with lots of small links like that is to make it peak limiting. On AC power if the fuse opens as the current rises up the sine wave the energy released is the area under a tiny portion of the curve. If the fuse takes a 1/10 of a second or 6 cycles to open the energy under the curve is huge and will destroy the equipment. Fuses like this are used as a backup to circuit breakers because a circuit breaker simply isn’t fast enough to limit the peak current.

                Those links? There is a good chance they were pure silver!

                Comment


                • #38
                  Originally posted by garyhlucas View Post
                  A waste of a very expensive fuse. The reason that the fuse is built with lots of small links like that is to make it peak limiting. On AC power if the fuse opens as the current rises up the sine wave the energy released is the area under a tiny portion of the curve. If the fuse takes a 1/10 of a second or 6 cycles to open the energy under the curve is huge and will destroy the equipment. Fuses like this are used as a backup to circuit breakers because a circuit breaker simply isn’t fast enough to limit the peak current.

                  Those links? There is a good chance they were pure silver!
                  Well, his video does have over 3 million views, there’s a chance the fuse paid for itself plus more.

                  Comment


                  • #39
                    Anyhow, here’s what an Arc flash of the power they are playing with will do to your body. Don’t worry, nothing gruesome to see as the body is atomized.
                    164 votes, 53 comments. 237k members in the MakeMyCoffin community. We serve educational value by bringing awareness to the dangers of every-day …

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                    • #40
                      I have done some work involving maintenance and testing of such high current metal clad switchgear, where we removed breakers from cubicles, cleaned, lubed, and performed visual and electrical testing, which included hipot insulation testing, contact resistance tests, and primary injection testing which involved long time, short time, and instantaneous trip tests at currents of typically 3x, 6x, and 10x rating. Trip times are typically about 90 seconds at 3x, 0.5 seconds at 6x, and 0.05 seconds at 10x.

                      My friend Ken, for whom I worked quite a few years, was doing overnight maintenance at a large night club in Baltimore called the Power Plant. His older, highly experienced partner was using a wrench to tighten some bus bar connections when it slipped and fell across two lines of the incoming feed, which was probably 480 VAC and 2000 amps or so. It welded in place across the bus bars and caused an arc flash and fireball that persisted for a few seconds, after which an external fuse eventually cut power. Ken saw him drop the wrench from maybe 10-20 feet away and just had time to raise his arm and turn away. He was badly burned but survived, while his partner was critically injured and died after a few days of pain in the hospital.

                      In the course of designing and building electrical test equipment, I watched a film made by Bussmann Fuse Company, that showed full power destructive testing of low voltage (600 V) switchgear, and it showed how a molded case circuit breaker would typically be destroyed even when successfully clearing an overcurrent fault within its interrupting rating (typically 5,000 - 20,000 amp), whereas a similarly rated fuse would just quietly break the circuit with a puff of smoke. It might exhibit more damage at its interrupting rating of 100,000 to 200,000 amps, but the fault was still cleared without much drama.
                      http://pauleschoen.com/pix/PM08_P76_P54.png
                      Paul , P S Technology, Inc. and MrTibbs
                      USA Maryland 21030

                      Comment


                      • #41
                        I wonder if all this really belongs to a machining forum... First we're invited to see sutured hands, now we are enjoying vaporized bodies... Do we really need to continue? How about someone showing a photo of his hemorrhoids being fixed? Or a colonoscopy video?
                        Last edited by MichaelP; 09-22-2021, 02:57 AM.
                        Mike
                        WI/IL border, USA

                        Comment


                        • #42
                          Originally posted by RB211 View Post
                          Anyhow, here’s what an Arc flash of the power they are playing with will do to your body. Don’t worry, nothing gruesome to see as the body is atomized.
                          It asks me if I'm over 18 (yes) and do I want to see adult content. What in the world are they doing? Adult content? Anyway, I'm not opening it, not having any record that I've been watching 'adult content' on my PC
                          'It may not always be the best policy to do what is best technically, but those responsible for policy can never form a right judgement without knowledge of what is right technically' - 'Dutch' Kindelberger

                          Comment


                          • #43
                            Originally posted by PStechPaul View Post
                            I have done some work involving maintenance and testing of such high current metal clad switchgear, where we removed breakers from cubicles, cleaned, lubed, and performed visual and electrical testing, which included hipot insulation testing, contact resistance tests, and primary injection testing which involved long time, short time, and instantaneous trip tests at currents of typically 3x, 6x, and 10x rating. Trip times are typically about 90 seconds at 3x, 0.5 seconds at 6x, and 0.05 seconds at 10x.

                            My friend Ken, for whom I worked quite a few years, was doing overnight maintenance at a large night club in Baltimore called the Power Plant. His older, highly experienced partner was using a wrench to tighten some bus bar connections when it slipped and fell across two lines of the incoming feed, which was probably 480 VAC and 2000 amps or so. It welded in place across the bus bars and caused an arc flash and fireball that persisted for a few seconds, after which an external fuse eventually cut power. Ken saw him drop the wrench from maybe 10-20 feet away and just had time to raise his arm and turn away. He was badly burned but survived, while his partner was critically injured and died after a few days of pain in the hospital.

                            In the course of designing and building electrical test equipment, I watched a film made by Bussmann Fuse Company, that showed full power destructive testing of low voltage (600 V) switchgear, and it showed how a molded case circuit breaker would typically be destroyed even when successfully clearing an overcurrent fault within its interrupting rating (typically 5,000 - 20,000 amp), whereas a similarly rated fuse would just quietly break the circuit with a puff of smoke. It might exhibit more damage at its interrupting rating of 100,000 to 200,000 amps, but the fault was still cleared without much drama.
                            That's a prime example of what I said about s h i t happens and "nothing can go wrong".

                            A bit of electrical tape around all but the jaws of that wrench would have prevented it from shorting out the bus bars.
                            Location: Saskatoon, Saskatchewan, Canada

                            Comment


                            • #44
                              Originally posted by Arcane View Post

                              That's a prime example of what I said about s h i t happens and "nothing can go wrong".

                              A bit of electrical tape around all but the jaws of that wrench would have prevented it from shorting out the bus bars.
                              That "bit of tape" might not have been so great..... Impact on an edge might well cut through the tape with the same result.

                              Tape needs several layers to begin to be "protection". And usually there is some other material wrapped on before the tape, when covering anything that has potentially sharp edges.

                              Better a sleeving of something thicker and tougher, such as heatshrink tubing on the handle, possibly two layers of different types. Something fibrous would be better against cut-through.

                              You just don't want to be near a couple foot diameter ball of plasma at several thousand degrees.
                              Last edited by J Tiers; 09-22-2021, 11:03 AM.
                              2730

                              Keep eye on ball.
                              Hashim Khan

                              Everything not impossible is compulsory

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                              • #45
                                Originally posted by J Tiers View Post

                                That "bit of tape" might not have been so great..... Impact on an edge might well cut through the tape with the same result.

                                Tape needs several layers to begin to be "protection". And usually there is some other material wrapped on before the tape, when covering anything that has potentially sharp edges.

                                Better a sleeving of something thicker and tougher, such as heatshrink tubing on the handle, possibly two layers of different types. Something fibrous would be better against cut-through.

                                You just don't want to be near a couple foot diameter ball of plasma at several thousand degrees.

                                Ya think!!!
                                Location: Saskatoon, Saskatchewan, Canada

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