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Admin
And now you've learned from this story that the proper reaction is to start leaving your fast food trash on the floor for them.
Admin
I've worked in a GM UAW plant for close to 20 years. They were/are nasty when it comes to computers. They insisted that they should be doing things like fixing large UNIX servers. We got around that one (it's under a service contract, you can't get the spares, and don't have the training), but a UAW guy had to stand next to the guy that came in to fix them. You could not pick up a PC and move it from one desk to another if your office moved.
A GM IUE or IBEW plant was much better to work.
I've also worked at power plant with IBEW. No problem working with them.
Admin
I would expect such rubbish in countries like Russia or China. I mean, keeping a note about someone making fart noises or writing a nasty word is ridicoulous. This is something like everyday practice at school. When I think how often I said "Scheisse" at school, I would have been shot by the age of 15.
And if the FBI is reading this post: Scheiiiissseeee, Scheisse, Scheisse, fart, fart fart, fuck, fuck, fuck. Now, I deserve being thrown in prison?
Admin
You didn't have management that wanted to get out of paying workmans compensation for an incident that happened while you were turning on the computer.
Admin
You have probably never touched the spark plug on a running engine. That's some 5000 V with some µA and doesn't kill you at all. Whereas I wouldn't like to be in the starter circuit when you start the same engine and that's a mere 12 V current but some 100 A and that could be dangerous.
Admin
Don't apply Ω's (please don't capitalise) law to AC
Admin
Actually it was resistance, not persistence.
Admin
Ohhhh, the irony!
Admin
Electricity newbie here. It seems like there are several experts leaving comments here, so here goes...
I was recently changing a light switch in my home. I touched a live wire after disconnecting it from the switch to unbend it; the old switch had a screw that the wire wrapped around, and the new switch had a hole that the wire got inserted into on the back, and a screw clamped down onto it from the side. So, I first tried to unbend the wire with my hands, and I was fine (no shock), but the wire wouldn't bend. So, I got my Leatherman pocket tool--which has a metal handle--and grabbed (more like clamped down on) the wire with the built-in pliers. I got a really nasty shock from that, which I could feel inside my head. I was tingling for a little while afterward and I had a headache for the rest of the day. I eventually found a pair of needle-nose pliers--with a rubber handle--and finished the job with those. You can bet I touched the wire with the tip of the needle nose pliers lightly at first. I think it took like four or five pokes and prods before I felt comfortable enough to grab onto it.
A couple of questions to those more knowledgeable here about electricity: Why didn't I get shocked from touching the wire bare-handed, but I did get shocked when an extra piece of metal was placed between my hand and the wire? Was I in any sort of danger while doing this, or was the shock basically harmless? What are some good resources to learn more about electricity so I could accurately predict and prevent something like this from happening again? I've had a few different people try to explain to me the differences between amps, volts, hertz, watts, ohms, AC, DC, etc., and how they all relate to each other, but it just hasn't sunken in yet.
Admin
Just because it didn't happen to you doesn't mean it didn't happen to me. This story is most patently true. I can provide names, dates and location, as well as witnesses to back me up. Just because GM's union works correctly doesn't mean other locations don't. We're talking TVA here, in 1990.
The reason this occurred is that the person who left the relay cover off was buddies with the safety officer and they loved to find loopholes to their advantage. If you don't think things like that happen, then I don't know what to tell you.
Admin
Back when I used to be an inspector in steel plants I was one of the only non-union employees there. I got dinged for unauthorized use of welding equipment. How did I use it? The welder left cables laying on a catwalk, with a welding rod still attached and the welder turned on. Since there was no one from the electrical union around, I was not permitted to turn on the lights. This resulted in me tripping over the live welding lead and causing the welding rod to weld itself to the catwalk.
Needless to say I in in a new line of work now.
Admin
Admin
As a side note, in the future, if you're going to be working on electrical stuff in your home, find and open the breaker switch that controls that circuit first. Then you won't have to worry about getting electrocuted. I'm kind of surprised you didn't do that after getting shocked the first time.
Admin
10 points to the person who guesses what the resistance of the circuit is so that 12V produces 100A. A bonus 10 points if you can figure out the reason why you could safely grab that circuit, or even insert yourself into the circuit (in series) without suffering more than a case of the tinglies.
Admin
Why not? V, R and I are now complex numbers when dealing with AC.
Admin
Make sure to put a sign "DON'T TURN ON! PEOPLE WORKING!" on the switch. There are too many idiots around.
Admin
Long ago, between two jobs, I was giving a hand to a friend who operated a small retail store in the basement of a house (this was one of those neat “jobs” where you paid yourself straight out of the till every day before leaving — yeah, I’m that trustworthy).
One day, when I was keeping the fort, the landlord shows up with a plumber. “The tenant upstairs has no hot water”. So I go with them in the furnace room where the water heater is located.
The plumber opens the fuse box, and puts two fingers straight accross the two 220 volt phases.
I know that when you work on high-voltage circuits, you should use only one hand, but this was pretty extreme…
(No, there wasn’t any juice)
(CAPTCHA: “persto” — Why not “pesto”? It tastes much better)
Admin
This is wrong. Very wrong. A small amount of current flows through the birds. It isn't much, because the voltage difference between their feet is small, and dry skin is relatively high resistance. But current flows up one bird's leg and down the other.
A small amount of current flowed through your dad. If the voltages involved had been extreme (though not unheard of in industrial settings), he would have fried. Without touching the ground or "completing a circuit".
Think of it this way: if you build a small canal parallel to the Mississippi, will water magically stay in the river? Or will water flow through both?
Admin
And what equipment, outside of a lab, is powered off such a device? Current regulation is, I imagine, useful in some lab experiments, but not so much in the real world. Imagine trying to power logic off of it: if the PSU determines you're not doing enough thinking, it starts upping your '1' voltage.
Admin
Admin
TRWTF is union labor. Nice.
Admin
[Note to experts in the above areas: I know these statements are simplifications !]
Admin
I'm kind of suprised he didn't do it before getting shocked the first time. If I'm ever doing anything more than changing a light-bulb I'll shut off the power to that circuit first.
Admin
Perhaps, but I make up for it with my sparkling wit and personality.
Admin
I emailed several of my work colleges this article and we all had a good old chuckle as we know the same would happen here. The idea of a watch dog timer setup like that seems kinda silly, and the fact that the relay was left open was just stupid. Does this person work in Rio Tinto by anychance?
Admin
WTF
Admin
So long as it's truly only one you're safe. Observe power line workers working on live wires. They're very careful about touching only one and ensuring there is no ground path.
I personally have touched 100,000 volts with no effect--I was careful about ground paths. This wasn't actually dangerous as there wasn't the current behind it to do more than hurt if you made a mistake. (And all of us did at times.)
I've also seen a teacher at 300,000 volts. He did get a bit hurt but only from being careless. It was after the demonstration was over and he forgot to get rid of the charge properly. He was no longer touching anything, the generator was even off. He stepped down from his insulator--and limped around the room for the rest of the class period when his body discharged (simple capacitance can pack a punch at that sort of voltage) through his little toe.
Admin
Good point. That brings back memories from childhood. I was trying to plug in one of those plugs with a transformer in it in a very awkward position. Somehow I managed to touch both sides of the plug itself while it was far enough in to be hot but not far enough to keep my fingers away. (I have no idea how I managed this--I couldn't see what I was doing at all.) 110VAC, hand to hand. I did feel it but that's all.
Admin
"Human skin requires >7 Vrms to break the skin... Human skin requires >7 Vrms to break the skin..."
Those comments fall somewhere between wrong and meaningless. Refer to Wikipedia, topic "Electric Shock", paragraph "Lethality of a Shock". Lethality depends on amps (at least 30-100 mA), skin and internal resistance, and perhaps frequency. And of course health, time exposed, and so forth. The power source needs to be strong enough to provide the necessary voltage to drive that current through the body's resistance under existing conditions.
Admin
What do you mean? 50V or 1A? Human resistance hand to hand is about 200kOhms (hands dry, just checked ;D). So you can have 50V with 0.25mA or 1A with 200kV (situation dramatically changes if ou hve your hands covered with sweat)
Admin
No, you should be using Z for impedance instead of R for resistance if you're treating the terms as complex numbers.
Admin
So you're the monster hiding under my bed!
Admin
I used to work for a company that worked with a NOC in a very large telecommunications company in Atlanta. This NOC was a previous AT&T shop many years previously, and the computer nerve center was also a union shop back when it was nothing more than a huge phone switch center.
Enter "Carl." Carl was in his late 50s, overweight, and barely spoke a word to anyone unless they violated a union rule. Nobody is sure why Carl was on site, but he was the only union guy there. He had in some agreement that only HE was allowed to move equipment in this nerve center. If it was an "electric device," you could not bring it in, move it, or take it out with Carl doing it. This included laptops, cable testers, or anything that used a battery or power cord.
This was made twice as worse by Carl's attitude. He took forever to fill a work order, couldn't be found half the time, and worked in a closed and locked office where it was assumed he watched porn all day. When he did fill out a work order, he was very abusive to the equipment, often scooting things across the floor with his foot, kicking things out of the way, or using brute force to compensate for his awkward balance.
It go to the point that people had to sneak in and out of the computer center, and if Carl found out that some new server was move, or put in, or removed, he's either yank things back to where they were, or file a security report of "intruders." Luckily, he wasn't on the floor enough to memorize the location of everything.
That was over 10 years ago, so I don't know if he's still there.
Admin
All the union-bashing here is a shame. Unions and their rules do serve an important purpose, but all too often the enforcement of rules is absurdly overdone.
Its neat how the company tried to use union rules against the employee, and how Shawn was level-headed enough to realize that a head-on assault on bureaucratic lard just doesn't work.
And give a Twit-Of-The-Week award to the goober who ran around yelling for the Safety Officer.
Admin
What country keeps permanent records on workers ? Looks like a life sentence for minor offenses and too much control power over the worker by whoever writes these records.
Admin
"Does this look like a Q to you?"
Admin
No and no. It normally takes at least 30 mA to kill, and, unless you puncture the skin, you'll need at least 70 volts to push it through.
Also, you can't "grab 1A of current", the current will depend on your resistance.
Admin
Something about the way the Union regulations are so pig-headed tells me that this story is set in the USA. That means that the voltage is less likely to be hazardous than it is in Europe. Not that I recommend getting shocked :-)
Admin
Colleague grabbed into a stripped wire some months ago. Shocked him thoroughly, but at the time didn't seem to be a problem. Turns out that it dislocated his shoulder and snapped something inside there. After continuing aches, he is now in physiotherapy. Thing will stay snapped, as an operation probably would break even more there.
So he got something permanent from this seemingly innocent stint. Please do beware of live current.
Admin
Well, but first you will have to convice Mr. Ohm that his law won't apply here.
(R_body > 50 Ohm)
Admin
It may not take a lot of current "if properly applied" to be potentially fatal, but it’s also extremely unlikely that the jolt he received traveled up his arm and though his body in that manner. Usually people administer themselves a localized shock that runs from one part of their hand to another part of their hand, and is painful but not life threatening, (unless you are scared to death). That is why we all know lots of people who have been shocked by household current, but it’s very rare to hear about one of them dying. We are usually blessed by the fact that we are not usually well grounded and dry skin has a high resistance, thus we usually just get a good scare and maybe a small burn. All that said, since the potential to do great harm is there, no one should leave powered and exposed connections for any voltage over 50 volts.
Admin
Compensation for something that has the potential for a serious outcome. As a layman I thought you got compensation for an actual injury. Are you a lawyer?
Admin
Since no one else did...
V=IR -> R = V/I = 12V / 100A = 0.12 ohm
And for the second 10 pts - shouldn't it work in either series or parallel? Adding yourself in series (one site I just found lists the resistance between a person's hands at 1M ohms) raises the resistance high enough that the amperage drops way off. But since your resistance is that high, adding yourself in parallel means more than 99% of the current should flow through the existing circuit anyway.
Admin
It depends on wattage. 1 A won't do any harm if it's just 1 V over an hour.