Perspiring man electrocuted by his PC
By Darren Murph 
posted Jul 31st 2007 11:40PM
posted Jul 31st 2007 11:40PM
A 20-year old student in Shanghai's Yangpu District perished after being "electrocuted by his computer." Reportedly, the man removed the external case from his desktop to prevent it from overheating in the non-air conditioned room, and when his legs came into contact with the innards, the resulting shock left him deceased. Initial investigations by local police confirmed that he was indeed electrocuted, yet there was no reason given as to why the individual refused to switch on the cooling system.[Via The Raw Feed]
Pwnt.
Maybe you didn't notice, but this guy is dead...
I noticed, hence the "Pwnt."
Honestly.....survival of the fittest
He told you he was hardcore.
Darwin award....check
Look, this is hilarious, and it was stupid of him to go against the warnings on the stickers ALL OVER THE BOX. If something says DANGER! HIGH VOLTAGE! all over it, and you still open it while its running, then you deserve to die.
>> individual refused to switch on the cooling system.
May I ask what you mean by this comment? Did you mean in his PC? What cooling system? Everything was already running. I'm quite confused.
I think they mean his air-conditioning, but it says he didn't have one.
the air conditioning, in the room. it seems pretty obvious from the post.
Well, the article already said there was no AC in the room... thus my question.
the room had air conditioning, but it wasnt on. it was therefore non-air conditioned at the time he was electrocuted. the police told reporters that he was indeed electrocuted, and im sure one of the reporters asked why he didnt just turn the AC on, to which the cops replied, we dont know.
I just figured that, being an American site, Engadget assumed that everyone has AC. That might be hideously unfair of me.
That computer looks deadly alright!
That's really sad ;(
I've gotten a shock from powersupply before, but I wonder what gave him enough jolt to kill him...
How could he be exposed to voltage over 12 volts inside a normal computer? The power supply takes care of the 110/220 volts unless its an old emac type computer with a crt in it.
Thats what I thought too
Just because it's low voltage, doesn't mean it can't kill you. If he was indeed "perspiring" as the title suggests, then that could lower his skin's resistance enough for the few amps the power supply puts out to be fatal.
Volts don't kill you, current does. gb2 basic electronics
It's not the voltage that can kill you it's the amps. For instance a stun gun can have 50,000 volts but very low amps therefor it won't kill you. All you need is 6 milliamps across the heart to cause cardiac arrest and I'm pretty sure a computer has at least that or more. Also moisture and the salts in the sweat could have amplified and also given a more direct path to the heart. Plus 110 volts can be more dangerous than 220 or 440 as it "holds" you to the source as opposed to throwing you back like the others so you get a longer charge from it.
The original article mentions 380V, which is two or/and three-phase powersupply, which isn't your regular household computer. So if it is a mainframe computer, that would partly explain why the individual would refuse to turn on the air condition, due to that the sum of both running a mainframe and using an AC in an enviroment that wont let you use that much power at the same time.
It does not however explain why live parts were exposed in such way the individual would come in contact with them. He might have removed any cover for the PSU because that might have been one of the parts that were overheated and not the CPU or GPU as in a regular standard computer.
Chinese power supply is 220V. That is enough to suck you in and electrocute you pretty fast. I remember when my mother told me back in China not to play around the huge transistor because of this very reason.
@Ratchet the Lombax: True that it's the amp, but i am quite certain the bodys internal resistance makes sure the ampere will be kept kinda low at low voltages unless you somehow short-circuit you heart directly which in this case did not happened. It was his leg that came in contact with the live parts. And about the stun gun issue, deaths have occurred, but usually on individuals that are sick/old or have other issues. There's a difference between the small ammount of power needed to prevent your heart from controlling itself and the chock you get from a stun gun. Both can be lethal.
You guys have the current issue all mixed up. Sure, if you get enough current through your heart it will kill you, regardless of the voltage. But there's no circumstance where 12 volts through your body will produce enough current to harm you. Your body's internal resistance is much too high.
Suppose you get your hands wet, salty, and as conductive as you can make them. Now you grab the two sides of a 12 VDC power supply, positive in one hand and negative in the other.
It's very unlikely that you will even feel any current. You certainly won't be hurt. Heck, you could attach needles to each terminal and poke them in your fingers, bypassing your skin resistance completely. You won't be electrocuted. Your worst injury will be from the pinpricks.
Take a couple of 9 volt batteries and snap the + of one and the - of the other together, so now you have 18 volts across the two exposed terminals. Get your hands conductive again and press a finger of each hand against those terminals. Still not enough to hurt you.
Stick one of the contacts against your *tongue* and grab the other with a wet, salty hand. Still nothing. You might get a bit of a tingle on your tongue, but nothing like the tingle you get when you touch your tongue across the contacts of a single 9V cell. (You've done that, haven't you?)
And it's not because a 9V battery has limited current capacity compared to a 12V power supply. It's all about your body's internal resistance. Low voltage across high resistance equals low current. It has nothing to do with how much current the power supply *could* deliver. With that high resistance, it just won't deliver much.
What could have killed the guy, then? A ground fault is a very likely possibility, as Hemat suggested. Or some other kind of electrical fault. Not 12 volts.
@ Ratchet:
1mA across the heart is enough to kill (depending on the individual).
3mA across the heart causes ventricular fibrillation which can cause death.
6mA across the heart almost guarantees death.
Also 110V is not more likely to hold you than a 220V supply. It again depends on the current flowing through the muscles. 1-2mA causes sustained muscular contraction.
@ Michael Geary:
The human body doesn't actually have that high an internal resistance. Blood is a great contuctor. Its only the skin which provides a high resistance - dry skin has a resistance of about 10kOhm, and damp skin about 1kOhm.
Doing the maths: V = I x R
1mA through a 1kOhm resistance, needs 1V across the skin.
Even if he had dry skin:
1mA through a 10kOhm resistance needs 10V across the skin.
So in fact 12V from a computer power supply is sufficient to cause at least some damage.
@Denise
Show me your reference for those resistance figures. 12v isn't going to kill you.
Michael Geary has it right... and most likely a ground fault and the fuse at the switch is either hard wired or there is not a fuse at all!
I totally don't understand this - what computer has enough voltage running through it to kill someone? I think there are some missing details .
Unless I have no idea what I am talking about, which is quite possible. Feel free to correct. A sad story either way.
Doesn't matter how much voltage hits you, it's the current. Considering the current carried in a typical psu, it could easily kill you.
I guess the advice "Don't sweat it!" really could be a lifesaver. Shocking how that stuff helps.
in before the "should have gotten a mac" comment from some iboy.
im not going to thread jack, but i'd like to point out:
my mac has never shocked me once. the kid should have gotten a mac, bill gates is obviously trying to kill ou
Bill Gates doesn't make computers, he runs a software company that also makes a few peripherals. And my PCs never shocked me, and I swap parts out while it's running, something that could easily be fatal in an old CRT using iMac.
This sounds like an urban legend. Where did it happen?
Nevermind, I see the where. Still sounds like an urban legend.
Your mamma's an urban legend.
The only thing in a computer that could come close to killing someone would be the capacitors in the power supply, those things are heavy duty but still you'd have to really try to get at the contacts on those. Something seems fishy about this.
I seriously couldn't see how this could happen.... Did he have the PSU cracked open? Jeez if so thats idiotic.
if he had the psu opened then i think it would be Darwin's law in effect
"The young man, who was identified as Wu, reportedly opened the external casing of the computer's **CPU** to prevent it from overheating"
Erm... CPU... that's got a whopping 1.37volts passing though it, maybe up to 3 on very old computers. It's also a part inside a computer, and I'm not sure you can take the casing off. I guess the journalists over a shanghidaily.com don't undestand the difference between a computer case and a processor.
The world may never know if there's any validity to this story at all.
The only possibility I can come up with is that this guy actually took the casing off of the PSU (Power Supply Unit) and managed to get his leg on a capacitor, or worse, just made contact with cords running to the wall. If this is the case, I'm officially nominating this guy for the Darwin award.
the tower is often referred to as the cpu. im sure thats what they meant.
@Terc
Today my mother referred to my tower as a "hard drive". I kid you not.
CHINA? CCTV anyone?? They must've caught him spreading news to his fellow citizens so they came to his house and tasered him to death while calling it a computer "accident".
Its another step from the communist government to set an example!
Machine: 1
Human: 0
ive killed my fair share of machines thank you verry mutch!
You guys are assuming a normally working computer. It's not implausible that some sort of short was causing the case (or whatever metal in it he touched) to be energized?
I remember back in the day when I was obsessed with totally silent pc's, I took the PSU out of my old PIII and removed the outer casing so I could remove the last fan from the system. I just had the guts sitting on top of the CPU case under my desk. Ahh to be young and reckless again.....
Yea I believe this one. Let me explain. I lived in china before and we had built our own computer (not the best grounding in the chinese home grown power supplies). We had ac but our power was on a pay meter device just outside the door. So you had to get these cards to keep it full (kind of linke feeding a parking meter). So AC runs your credits down real quick. This guy probably had the choice between the computer or the AC. Second power is really bad in China. We had a voltage regulator and surge suppressor hooked up to ours. The power spiked really high (over 480v) and caught the computer on fire. If we had had the cover off, like we often did, i'm sure something like this could have happened.
yours is the only sensible comment here. thank you. i think it's hard for most of these geeks to remember that the rest of the world isn't like livermore or orange county. you guys really should get out more...
In my experience, if you don't ground your box, there would likely be a float voltage across the transformer-less SMPS, which may spread to various parts of the box and any other device wired to it.
Then, if you are sweating or wet, and come in contact with a grounded object and the float voltage at the same time, enough current may pass through your body to, well, kill you.
When I said 'in my experience' above, I meant only the first part. I know you people realized that.
Well, it's pretty unlikely that the PSU is transformerless. After the primary side rectifier and the primary FET there's usually a high frequency transformer in order to lower the switched voltage before recifying it again to +12V. Perhaps a forward or flyback topology type (or any of the other common ones). Theoretically you could get rid of the transformer but that would make the duty cycle so low that it would be difficult to regulate the output voltage. Another reason (or more of a bonus) for using a transformer in the PSU is to electrically isolate the input from the output.
Honestly, this does make sense in all of it's nonsense.
First of all, if you remember physics class, 1 milliampere CAN kill you.
Second of all, it all depends on conductibility and resistance. Some human beings are better at conducting electricity, some of them are better at resisting it. In the case of high resistance, you get health risks, potential burns and in some cases, death.
Last but not least, in the case of someone having a heart condition, heavy moisture on the points of contact and a small amount of voltage / amperage, there are a lot of risks involved including chances of injury and death.
Now, as an experienced electrician, I've had many shocks and electrocutions occur to me in the passed years and fortunately I've survived them all. As mentioned before, some people are at higher risk then others and a few volts / amps can kick you deep to your grave.
Please, when playing with electricity, remember this young man's horrible faith.
just a sidenote, electrocution is death by electrical shock. surviving an electrocution is like surviving a murder.
Perhaps this man is a zombie, in which case isn't everyone glad the stocked up on shotgun ammo?
You guys have to stop posting these death stories. They just spawn uncomfortable debates about morality, selfishness and compassion.
Its 40 degrees celsius and incredibly humid right now (to the point that most expats escape for the summer. So sitting with a computer in a room with AC i could see how enough liquid could be generated.. as for a computer with 380 volts, wouldn't surprise me of its a Chinese special machine.. i.e home hury rigged thing.. it is China after all!
According to the CDC human skin has a resistance of 500 ohms.
using V=IR:
12=I500
I=12/500=24mA
Also, according to the CDC Amps have the following affects
1 mA Barely perceptible
16 mA Maximum current an average man can grasp and "let go"
20 mA Paralysis of respiratory muscles
100 mA Ventricular fibrillation threshold
So, it appears to be plausible. My only problem with the CDC article, I would assume skin would have a resistance per foot - but I didn't see any indication about that. I would like to see a mythbusters episode about it though
oops, I meant to cite my work....
http://www.cdc.gov/niosh/elecovrv.html
More revision to my work, maybe not so plausible. It takes high voltage to lower the skins resistance to 500 ohm. For low voltage under wet conditions, the worst you'd see is 12mA, which is not a letal level.
"resistance per foot"
I believe you're talking about resistivity - which is resistance per volume
The resistance of a material is given by the equation
R = pl/A
where
p is the resistivity.
l is the length in the direction of current travel.
A is the cross-sectional area.
considering that skin is very thin and that he had damp/wet skin.
l would be very small, and A would be very large.
This gives a relatively low resistance although the exact figure depends on p.
"resistance per foot"
I believe you're talking about resistivity - which is almost resistance per volume (because it actually depends on the shape of the conductor).
The resistance of a material is given by the equation
R = pl/A
where
p is the resistivity which differs for each material, and has different values for varying temperatures. Generally, insulators have a high value of p, and conductors have a low value of p.
l is the length in the direction of current travel.
A is the cross-sectional area.
considering that skin is very thin and that he had damp/wet skin.
l would be very small, and A would be very large.
This gives a relatively low resistance although the exact figure depends on p.
"waits for Mac comments"
this is scary, only because i do the EXACT same thing!!!
Remember, this isn't the US. This is China. There are probably less regulations on safety in China. You wouldn't see those battery recalls in China.
What kind of person are you?
You would love to see Bill Gates, George Bush, or even the Nintendo CEO to die? You might not like them, but you wouldn't mind seeing these guys die?
Nobody should die by accidents. That's kind of disgusting that you would say that. And Bill Gates? I think he's saved more lives, and will save even more, with his Gates Foundation.
He's very philanthropic and he's one of the people that brought us closer to the computer age. So I don't care what you say. Saying someone else should have died, is just plain stupid.
How many people just moved their feet? :D
Well Steve, in my opinion, the only person that would be better off dead as oppose to this poor guy would be you, not Bill Gates, George Bush or the Nintendo CEO. This is because they have changed the way are lives are in a way you never could hope to but more than that they aren't wishing YOU were dead.
Second what most other people who have actually been to the Middle Kingdom have said, as ridiculous as this might seem to people in other countries there are places where you might have to choose between appliances like a computer and AC, and with all the crazy computers I saw people running in Beijing I can totally believe the guy had a hardcore, heavy PSU that he probably vented in some crazy way, add perspiration and yeah, that'll kill ya.
I mean, half the time when you see people welding in Beijing they just shield their eyes with their hands, its not exactly the most well-regulated economy over there.
Also at whoever said somewhere near the top that George Bush doesn't want us dead, if you're 18-35 and able bodied I'm sure he would encourage you to enlist, and the way things are going overseas it amount to the same thing in the end. Doesn't excuse the ignorance of the comment they were responding too, but just because Bill Gates and Reggie Fils-Aime don't want us dead I wouldn't assume the same of Mr. Bush.
Of course George Bush doesn't want us dead. What is wrong with you? You're speaking of ignorant posts, and you say something just as ignorant as the others.
Congratulations.
what a way to go!
Okay, the death of Billy G, I'll let you off. The Death of George Bush, I couldn't actually think of anything better for the developing world, but still, I'll let you off. Maybe even the Death of Steve Jobs.
But what the hell has the CEO of Nintendo done to you!?
Wanker.
How dare any of you joke about this young man or wish death upon anyone. You people are horrible. If you lose a loved one, you would understand.
Voltage over 55V and current over 50mA together can kill. These values are for the worst scenario in a case when the skin resistance is minimal and the human is very sensitive to electricity. Obviously the current was higher than 50mA and the voltage higher than 55V.
BTW, I agree with some of the discussants here. The death of George Bush will be for the good of our planet and the solar system, but then he'll be replaced by another like him.
I have two buddies that just got back from Iraq, "friend", who would beg to differ with you on the value George Bush places on their lives. Guess its easy to love him as long as you don't have to die for him. I admire both those guys for their service, just wish it was to a more deserving commander.
As to the ignorance I was referencing before I meant the rest of the post where he mocked this poor chinese student, I stand by the George Bush statement. Maybe we've been watching a different war, but the one I've been paying attention to is a worthless bloodbath that wastes American lives and money in ways "big government liberals" could only dream of. Whether or not he actively dreams of dead young men and women, it is his hand stained with their blood.
Of course, since you've decided to call yourself Zeus THE GOD (because Zeus isn't obvious at all), I'm sure you'll handle disagreement the way he always does, yell a bunch and then go sulk in a corner, threatening to toss lightning at everybody but never doing it.
As mentioned only by "Johnny hates waiting," it was a matter of money. Though I'm thinking that most parts of Shanghai don't run on the credits system (not 100% sure, but none of my friends who lived there have mentioned that). My reasoning on why the A/C was off? Because he was too cheap to turn it on. So he removed the cover to his computer case to protect it from overheating. Which would make the room even hotter, causing him to sweat. Why not turn on the A/C now that he's sweating? Because he's trying to save money. I'm living in Taiwan, and all my friends and family are appalled at how I keep the A/C running when I'm at home (I'm from Houston, that's how I roll). They sit at home and sweat. Really. They just sweat at home, and refuse to turn on the A/C. They will have fans if it gets too bad, but go crazy if you leave the room for 5 minutes and neglect to turn it off during that time.
As said before, volts and watts don't kill. Current (amps) does.
As for the 380, that number is most likely referring to the wattage of the PSU; the journalist (or the translator) just doesn't know the difference, nor the real cause of death (same might be said of the cops). The forensics department in China doesn't exactly win awards every year. But there are capacitors in the PSU that can easily give a huge shock to someone.
My condolances to his family.
Why are some Americans so heartless when it comes to the death of human beings?
As for G. Bush, he has blood on his hands (mainly innocent Iraqi civilians and the civil strife he has caused, not so much US marines, dying is part of their job)
A recent poll said over half of Americans STILL believe Iraq was involved in 9/11...even though it's been repeateddly shown, and even admitted by the US Gov, that this is a blatant and utter lie, one of many lies spoken by the deceitful American Gov.
If you don't like it move to one of the wonderful third world countries where drinking water is as clear as mud, your computer can kill you if your not careful and the average life expectancy is about 30. That or you can shut the hell up and be thankful that you live here.
Yeah, I mean, Apple producing a somewhat usable media device disguised as a phone and Sony doing (absolutely) nothing to better it's image, they rule, and that belongs in an article about a young dead guy, right?
Moving along...Poor guy, I know what it's like, having no air conditioning, I've never had it, and even if I got a window A/C, I couldn't afford the bill to turn it on. I would theorize this is why he had his off, I wonder if some kind of electrocution protection isn't in order as with household appliances.
People are confusing the amount of energy needed to electrocute someone to death (burned to a crisp) vs. the amount of energy needed, applied at the correct time, to force the heart into an non-perfusing rhythm resulting in death (lack of blood flow). Both dead, but from significantly different causes.
You got two "buddies"? Right. Myself and those of us who have actually served may not agree with our superiors decisions, but we don't think that they sit around thinking about how they want us dead. They may be willing to have those who volunteered risk dying for what they consider greater aims, but I'm quite confident they would just as well get those aims without us dying. When you've served, then you can talk.
Yes, I have two friends, one from my high school in Missouri and one I know through a mutual friend, who recently returned from overseas. You're right, they've never said in so many words "George Bush wants us dead" but neither of them is very happy about the way things are going there either. After the spectacle that was Donald Rumsfeld testifying about Pat Tillman before Congress earlier in the week, how can you possibly think these people give a damn about the lives of soldiers? They don't even care if they lie about the death of celebrity soldiers. Imagine Ted Williams dying in a friendly fire incident in WWII and senior pentagon officials lied about it, doubt Truman would have won that election after that.
This goes beyond a political issue for me, I was just as angry when Bill Clinton sent an undermanned force into Somali and got innocent soldiers killed, the only bright side being the brevity of the situation.
As to my own lack of military service, I've considered it several times but I just don't think I have what it takes to be a soldier quite honestly. I respect those of you who do, and thank you for your service, it just burns me up when I feel that service is wasted. I don't know if you watched the YouTube Democratic debate, that crazy old coot Gravel about lost it over the "waste" of soldiers lives in Iraq and I couldn't agree more.
Sorry to get so offtopic here, the main point of my original comment was simply to scold others who were mocking the death of this poor Chinese student, and I inserted a blatantly political statement into my post (though I didn't start it).
Dibs
It's a marketing ploy conducted by Apple in China.
Whenever Engadget reports someone's death, I can count on the comments to remind me of the downside of cheap internet access.
The saddest thing is that he didn’t know he would get a better heat exchange with his case intact.
This is unlikely but there are plenty of things we don't know.
Who knows how much sweat there was! If it was that bad he might have shorted himself right to house current. There are plenty of other things connected to a computer besides that PSU its self that me introduce unwanted current. USB devices, DLS/Cable lines, even a standard phone line can give you a good jolt under the right conditions. Phone
You don't know what kind of condition he was in.
It's also obvious that newspaper knows very little about electricity... voltage doesn't kill you, amperage does.
In addition, its possible to withstand an amperage that's higher than normally "possible"... there's no set number at which current suddenly becomes deadly. What determines whether it is deadly is the path through your body the current takes.
If it goes across the side of your body into the ground, you may get burned and otherwise internally injured, but probably won't die. If it goes across your body (chest), then very little current can kill you. It doesn't take much current to interrupt heart rhythms to a fatal extent.
You have just been formatted.
-Windowz
@Blake, RedBull Runner, and anyone else who made similar comments:
Your comments are insensitive and stupid. Think about how you would feel if people were making the same type of comments about any of you if you were dead. Death is not "hilarious", or about "Darwin Awards", or deserving to die. The fact that you don't value life or the lives of others is warped and pathetic.
Grow up.
This makes no sense. Unless, somehow he managed to get his leg INSIDE the power supply, the +-5 and +-12 volts DC kicking around in the case are NOT enough to kill anyone. DC burns. AC electorcutes. You can go out to your car battery and hold both terminals all day if you want, nothing is gonna happen. Now touch wires from the terminals together, thats a different story. Thats call arch welding.
This is just really stupid and ridiculous.
Inside a computer smps there are actually quite high voltages across the smoothing capacitors it is not that uncommon to see 400v there. This voltage is generated by the collapsing magnetic field on the isolation transformer.
It could also have been an old AT-style computer - where the power supply switch is on the front of the case - there could be as much as 220VAC running from the power supply to a main disconnect switch at the front. Modern ATX power supplies don't have this anymore, but use a low-voltage contact to switch the power supply on.
That could definitely do it.