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kastein posted:Those kinds of plants (as well as aluminum smelters and refiners) are typically located very nearby to their power generating stations because of the gigantic load they represent. They often have to call the power company up and time their smelting operations so that the power company can bring power output up at the same time, else it'll cause widespread brownouts or blackouts. We have to warn the on-site power station when we are going to power cycle the Titan supercomputer so they can be ready for the huge swing in power. That tends to happen when a computer draws ~8.2 MW.
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May 13, 2014 16:43
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Rev. Dr. Moses P. Lester posted:Holy poo poo. https://www.youtube.com/watch?v=hfnEuRA7-vo This video appears to be about the same incident and has some explanation (and some gruesome details of his death). Basically his fatal sin was using a common 600v multimeter to probe a 2300V circuit. It touched off arc flash and sent a threw a mean fireball straight at his face, burning him to death. An Angry Bug posted:Please tell me it happens fast enough. Unfortunately, no.
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May 13, 2014 16:59
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SlapActionJackson posted:https://www.youtube.com/watch?v=hfnEuRA7-vo Haha, did you even look? Those two videos are completely unrelated. More than one dude has been fried by an arc flash.
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May 13, 2014 17:02
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An Angry Bug posted:Well, at least it happens fast enough that you don't feel anything. Nope, you get to spend whatever time you have left (seconds or days depending on how unlucky you are) in intense agony. I remember reading a story about a poor guy that got arc flashed and lived long enough to drag himself over to some coworkers in another room and tell them that he had "screwed up real bad" before dying. Arc flash is the main reason I don't gently caress with electricity more powerful than a vehicles 12v system.
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May 13, 2014 17:13
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An Angry Bug posted:Well, at least it happens fast enough that you don't feel anything. Unfortunately there is literally no one on this planet who can tell you with any authority how fast we lose awareness when we die. Anyone who has that authority is dead and is unable to communicate with us. Hey look, there's a case of someone using "literally" correctly. 
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May 13, 2014 17:18
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You can be fatally electrocuted by a 9 volt battery if you are dumb enough. http://www.darwinawards.com/darwin/darwin1999-50.html Play it safe when electricity is involved. I've felt a shock from 12 volts before, I was covered in coolant and accidentally leaned on the positive terminal of the battery. That being said, the rules for working safely with electricity are pretty simple and shouldn't be difficult to master.
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May 13, 2014 18:50
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Do all multimeters feed its entire voltage through the probes in resistance mode? I would expect there to be a resistor or something to prevent shorting it (and doing dumb stuff like kill yourself).
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May 13, 2014 18:57
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kastein posted:You can be fatally electrocuted by a 9 volt battery if you are dumb enough. http://www.darwinawards.com/darwin/darwin1999-50.html Holy poo poo! I didn't have any idea you could die from poking multimeter leads into your skin. That's insane.
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May 13, 2014 19:01
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Collateral Damage posted:Do all multimeters feed its entire voltage through the probes in resistance mode? I would expect there to be a resistor or something to prevent shorting it (and doing dumb stuff like kill yourself). Depends. Remember, most DMMs these days have resistance measuring scales up to 2 or 20 megohms. You need a couple volts (like, say, 9 volts) to have any chance at measuring that kind of resistance accurately. So if he had it on the highest resistance scale well there you go. No one thought of someone being determined and stupid enough to intentionally pierce their fingers with the probes, either.
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May 13, 2014 19:08
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Liquid Communism posted:Arc flash, the poor bastard. Something in that unit arced, and the resulting explosion turned him into chunky salsa from the resulting heat and explosive pressure wave as the copper went nearly instantly from solid to gaseous state.
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May 13, 2014 19:14
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Rev. Dr. Moses P. Lester posted:What was the guy doing when it happened, though? It looked an awful lot like he was sawing something by hand. Presumably turning a crank on the screw gear that was pulling the breaker into position. Those things are heavy and ride on rails to make sure they plug in straight.
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May 13, 2014 19:15
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IIRC the guy was trying to rack a large breaker and there was an obstruction preventing it from mounting smoothly. Instead of pulling the breaker out to check what was up he just kept shoving it in until...boom.
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May 13, 2014 19:43
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I actually have a Simpson 260 and was curious: 1x ohm setting will pass 89mA BUT it powers it from a single D cell battery. The 10,000x ohm setting uses the 9V battery for higher sensitivity but only passes ~30uA into a short circuit. In short I have no clue how he managed to do it unless it was an older model 260 which can have a 15V battery.
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May 13, 2014 19:52
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Last time that arc flash video showed up there were some related videos on YouTube of some dude that survived a flash and it showed how he was progressing as he got surgeries to put skin back on his face. It was made by his wife I think to show how well he was doing. I only watched a little last time and have no inclination to do so again but to be sure, an arc flash may not kill you at all. You may just have your face burned off. Anyway, I'll try to take some photographs of broken car parts to bring this thread back from the gruesome.
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May 13, 2014 21:05
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NitroSpazzz posted:We have to warn the on-site power station when we are going to power cycle the Titan supercomputer so they can be ready for the huge swing in power. That tends to happen when a computer draws ~8.2 MW. That poo poo cray.
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May 13, 2014 21:29
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kastein posted:You can be fatally electrocuted by a 9 volt battery if you are dumb enough. http://www.darwinawards.com/darwin/darwin1999-50.html
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May 13, 2014 21:37
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I thought that a great deal of the Darwin Awards stories were somewhat 'inconclusive' when people started looking for background info or testing to see if things can actually happen that way.
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May 13, 2014 21:40
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Amykinz posted:I thought that a great deal of the Darwin Awards stories were somewhat 'inconclusive' when people started looking for background info or testing to see if things can actually happen that way. EDIT: If I remember correctly from my biomedical instrumentation book the current required to cause ventricular fibrillation bottoms out at around 60Hz and then starts rising as you go up and down in frequency. Terrible Robot posted:Nope, you get to spend whatever time you have left (seconds or days depending on how unlucky you are) in intense agony. MadScientistWorking fucked around with this message at 21:58 on May 13, 2014 |
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May 13, 2014 21:46
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MadScientistWorking posted:Nope. Its not possible in the way the story describes it. Apparently it's documented in some navy accident report somewhere, and I saw some idiot at my college go away in an ambulance with my own two eyes after they hosed up wiring the heart monitor project (and then tested it without having the TA look over their wiring, as they were supposed to) in a microelectronics I lab, which was only powered off a 9V battery, so I'm gonna have to disagree. They didn't kill themselves, but they definitely hosed up their heartbeat and the EMTs were called. And they didn't pierce the skin, just used the normal conductive gel and contact cups that are always used for heart monitors. Also, I just stuck a 9V battery across my DMM here at work in current mode (it's good to 20 amps, so I wasn't concerned) and it registered 1.7 amps. That was a partially depleted battery I keep around for testing random stuff, not a fresh battery. Whether they were designed to or not, they can, at least for long enough to stop your heart if you're a big dummy. (Ohms law, for a minimum of 300-500mA to stop your heart with DC, says your internal resistance would be around 18-30 ohms maximum. Conductivity of blood is supposed to be around 0.667 siemens/m, which gives a total resistance for an average human with a 6 foot arm span of... drumroll... 3/4 of an ohm. At least if I didn't screw up my unit conversions, which is entirely possible.) kastein fucked around with this message at 22:05 on May 13, 2014 |
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May 13, 2014 22:00
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kastein posted:Apparently it's documented in some navy accident report somewhere, and I saw some idiot at my college go away in an ambulance with my own two eyes after they hosed up wiring the heart monitor project (and then tested it without having the TA look over their wiring, as they were supposed to) in a microelectronics I lab, which was only powered off a 9V battery, so I'm gonna have to disagree.
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May 13, 2014 22:05
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Please enlighten me then.
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May 13, 2014 22:06
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Sometimes it's the little things in life.
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May 13, 2014 22:49
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The Navy claims the threshold of potentially fatal current is 30mA, not 3-500mA. That being said, in the Navy there's a good bit of prank abuse of the megohmmeters, which will shock the everloving doolally out of the victim. That, or charge up a capacitor with said megger and leave it lying around for someone to pick up. Usually you'd only grab it with one hand, though.
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May 13, 2014 23:55
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Snowdens Secret posted:The Navy claims the threshold of potentially fatal current is 30mA, not 3-500mA. My grandfather told me the favorite shop prank back in the day was to charge up an ignition condenser then toss it to someone. Those snap-action magnetos (the ones that use some sort of black magic inside that makes them have uneven resistance to turning and always snap over and whip out a hot spark no matter how slow you're turning them) are good fun too. We kept one in the machine shop I fooled around in in college specifically to hand to newbies. Most people would fool with it, realize the shaft turned, realize they had to put more force into it at some points to actually make it turn, get a real good grasp on it (clamping their hand over the terminals in the process) and then shock the poo poo out of themselves. As for the current - 300-500 is what I found for DC on google, it may well be lower. Either way, a 9V battery is easily capable of stopping your heart if you are enough of an inquisitive/insistent idiot with it.
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May 14, 2014 01:05
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Das Volk posted:That poo poo cray.  This is seriously not getting enough love.
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May 14, 2014 01:41
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Das Volk posted:That poo poo cray. A good post CroatianAlzheimers posted:
 There would be a picture and words here but the Imgur app is being a gigantic pile of poo poo right now.
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May 14, 2014 02:07
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^^ CroatianAlzheimers posted:
Glad I'm not the only one who caught it!
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May 14, 2014 02:09
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kastein posted:Those snap-action magnetos (the ones that use some sort of black magic inside that makes them have uneven resistance to turning and always snap over and whip out a hot spark no matter how slow you're turning them) are good fun too. We kept one in the machine shop I fooled around in in college specifically to hand to newbies. Most people would fool with it, realize the shaft turned, realize they had to put more force into it at some points to actually make it turn, get a real good grasp on it (clamping their hand over the terminals in the process) and then shock the poo poo out of themselves. Impulse magneto  Oh God that reminds me of a stupid game we played when I was getting my private pilot license in the Air Cadets. The flying school we used had a cutaway Lycoming O-320 (the same engine as in most Cessna 172s) that had a live magneto attached to it. So being a bunch of stupid teenagers we'd get four guys to grab an ignition wire and a fifth to hand-crank the engine until someone had received enough shocks that they cried uncle or dropped their wire.
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May 14, 2014 03:01
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kastein posted:You can be fatally electrocuted by a 9 volt battery if you are dumb enough. http://www.darwinawards.com/darwin/darwin1999-50.html Wait, so you're saying he was... Bloodrocuted? https://www.youtube.com/watch?v=SbTc1SpjZSA
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May 14, 2014 03:07
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MrChips posted:Impulse magneto This is why you don't let pilots in the hangar...
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May 14, 2014 03:16
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MrYenko posted:This is why you don't let pilots in the hangar... The hangar? We don't go in the hangar...that's where the Morlocks live. just kidding we luv u guyz
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May 14, 2014 03:43
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"I thought YOU bolted the front axle on" "no, i thoguht YOU bolted the front axle on" "then who did....?" 
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May 14, 2014 03:58
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Looks like someone was trying to emulate those forklifts with the wacky wheels that let it move sideways.
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May 14, 2014 04:00
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I wish there was a backstory for some of these. Although for some you don't really need anything besides "russia" 
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May 14, 2014 04:05
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Help.... me....
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May 14, 2014 04:07
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I seem to recall that rotor being for a time attack car for short sprints and where every bit of weight counts.
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May 14, 2014 04:10
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I wouldn't put that on a time attack car. Auto-x maybe.
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May 14, 2014 04:12
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jamal posted:I wouldn't put that on a time attack car. Auto-x maybe. Yeah, I've seen that exact pic in autox circles. I'm wondering if thats the FSP rabbit that only makes it 2 runs before breaking....
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May 14, 2014 04:31
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Powershift posted:I wish there was a backstory for some of these. Although for some you don't really need anything besides "russia" Speed holes. They make the brakes stop faster. 
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May 14, 2014 04:37
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Root Bear posted:Speed holes. They make the brakes stop faster. Less weight = faster stop. Duh.
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May 14, 2014 04:39
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