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| Subject - What Kills | |
| David Hyatt |
I have always been told that amperage is what kills you not voltage. Please explain why this is a true/false statement. I met a cop today and he had a taser gun. He said it was 50,000 volts, maybe I think he said. To me this should kill someone. But it don't he said. Why? What if you had a pacemaker?
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| Ryan_J | For a typical female, 50 miliamps for 2/10 of a second, and for a typical male, 75 miliamps for 1/2 of a second will send the heart into ventricular fibrilation. |
| David Hyatt | How do you calculate miliamps? amps x 1000? What about high voltage little amperage? |
| JimmyDee | quote: Yes your formula is correct. Usually used for accurate lower amps under one amp. If you figure the adult body has a resistance of 10,000 to 100,000 ohms, you can calculate the number of volts it would take to get to the 50 to 100 ma it takes to kill you. If the source of voltage isn't enough to produce the number of ma to kill it will not. Keep in mind that the source of the shocking guns is a small battery and even though capable of producing a relatively high amperage at 1 or 2 volts, by the time it is raised to 50k volts, the amperage available is probably in the micro amp range and totally harmless. (as far a killing) Jim |
| Scott Vickrey | Wait, wait. Jim, I know you know what a milliamp is, but the formula is incorrect. Amps x 1000 = KiloAmps 1 amp = 1000 milliamps or 1000 ma 1 ma = .001 amps 500 ma = .5 amps David you are correct the voltage doesn't kill you the current does. Voltage is a measure of electrical potential and current is a measure of electron flow rate. Knowing this now we can say It's not the electrical potential(voltage) that kills you it's the flow of electrons(current) through your body that does you wrong. If high voltage alone killed then dead birds would be raining from the power lines. Here's an analogy to help with the high voltage low current thing. You have a large air tank(service). It's pressure is 120 psi(voltage). The valve is closed (high resistance). When the valve is opened(low resistance)it blows strongly for a long time(high current). Now consider this, You have a tiny peanut sized air tank(capacitor). It's pressure is 50,000 psi(voltage). When the valve is opened it blows a little air for a fraction of a second and it's depleted (low current). The volume is important. If you had a pacemaker I would think you wouldn't want to get shocked period. The high voltage might fry the electronics in it. Ryan, where did those statistics really come from? Where did they get their test subjects? Death row? |
| cs409 | depends on if the woman is a very upset house wife,,,if so it could take 300 to 400 amps for at least 1 min to take her down LOL reference NOW magizine LOL. |
| JimmyDee | Scott, I think Daves formula is correct. Your numbrers are correct but think about it. 1 amp x 1000 is a thousand ma. Soooo amps x 1000 is milli amps. Amps divided by a 1000 is kiloamps. 1000 amps divided by 1000 = 1 kiloamp. Right answers, wrong formula. Dave I'll stand with my answer, you are correct. Jim |
| cs409 | 1 kiloamp = 1000amps 1 milliamp = .001amps 50mA would be .050 (50 x .001 = .050A or 50mA )for the women,,,and (75 x .001 = .075A or 75mA )for the men..... Ventricular Fibrillation What is ventricular fibrillation? The heart beats when electrical signals move through it. Ventricular fibrillation (ven-TRIK'u-ler fib"rih-LA'shun) ("V fib") is a condition in which the heart's electrical activity becomes disordered. When this happens, the heart's lower (pumping) chambers contract in a rapid, unsynchronized way. (The ventricles "flutter" rather than beat.) The heart pumps little or no blood. at 200mA or .2A the heart clamps down,,,aka, no pumping at all..... |
| LIVEWIRE | Isn't it amazing how these discussed values tie out the the designed fault current trip-level of a GFI receptacle or the "squak" level of a hospital operating room LIM panel? |
| John A. Peters | I would like to suggest that since vols times amps equals watts then it's really the number of watts that pass through your heart that would do the damage. Of course as you say you have to have enough voltage to force enough amps through the resistance of the body. I wonder if the electricity causes the heart to overheat or does it messed up the electrical circuits? I guess maybe both. |
| JimmyDee | Had one person I knew got 13,200 hand to hand. They said his blood vessels from one hand through his heart, to the other hand blew apart because the blood boiled, turned to steam and exploded. Died almost instantly. Jim |
| LIVEWIRE | Volts x Amps x PF = Watts Volts x Amps = Volt-Amps |
| Dave Nix | quote: (Edited for continuity) |
| tonytude | Then what kind of current does the paramedics use to revise you after your heart stops? Defibrillator? |
| JimmyDee | quote: They zap you with DC voltage and give you so many joules of the stuff. Jim |
| Ship Shock | This is a sea story, so I cannot vouch for its' veracity; We have some ships up on the Great Lakes that, because of the freshwater environment, and attendant absence of rusting, were built back in the Twenties and Thirties. Some of these buckets were wired up by the "Edison Electric Company", and run DC voltage all over the ship...that old. Unfortunately, their switchgear is also 1920-30's "State of the Art"...like Frankenstein's laboratory. Open knife switches, live front panels, stuff that would make MY blood run cold. Legend has it that an engineer was wearing a nylon windbreaker on a cold, dry day, towards the end of the shipping season, and his movements generated enough of an electrostatic charge on him for an arc to jump from the panel he was walking past to his shoulder. Purportedly, the current grounded through the deck plate he was standing on, blowing his heel off in the process. Cheers; |
| JimmyDee | quote: We are looking for how many milliamps there are in 1 amp. To find this, think about it, you have to multiply by 1000. 1 amp = 1000 ma. 2 amps would = 2000 ma. How do you arrive at this figure? Answer is to multiply the number of amps by 1000 and that will = the number of milliamps. Another example: .5 amps x 1000 = 500 ma. If I'm looking for the number of KA I would divide by 1000. 1000amps/1000 = 1 k-amp. I think we are both saying the same thing here but in different ways. BTW welcome to the Electrical Knowledge site. Jim |
| trekkie76 | If you have 1 amp and you multiply it by 1000 you have 1000 Amps, or to use the simplified version 1 kiloamp. If you are looking for milliamps you divide by 1000. 1/1000= .001Aor 1 milliamp. 1000milliamps=1 amp, so mulitplying 1 amp by 1000 will not get you 1000 milliamps. |
| trekkie76 | Jimmy. no math operation is required to convert 1 amp to 1000 milliamps. they are one and the same. part of your answer is correct, 500 Ma = .5A x 1000, but multipling a whole number not a decimal by 1000 will get you 1000 extras, not divide it into 1000 equal parts. |
| JimmyDee | OK for grins tell me how you would convert 2.5 amps to milliamps. You could of course move the decimal place to the right, 3 places which would produce 2.5amps = 2500ma. Please tell me how this is different than multiplying 2.5 x 1000. The answer is still the same. Lets do another. 1 amp = 1,000,000 microamps. Do this the same way only use a million instead of a thousand. Either move the decimal place 6 places to the right or multiply number of amps by 1,000,000. Either way 1.0 amps will = 1,000,000 microamps. Or 1,000,000 of these(1/1,000,000 also written 1x10 to the -6 power amps or .000001 amps) Jim 
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| Kraze | It is amperage that kills you but a stun gun even though it's 20,000 volts it can not produce enough amps be cuase of it's power source wich is probly a 9 volt batery. The same with the ignition spark of a car wich is about 20-70,000v (depending if it's stock or high preformence)theres just not enough amps.unlike a power source of a AC power system 240v can easly kill you becuase will allow enough curent to flow. |
| trekkie76 | if you had 1 orange and wanted 999 more, wouldn't you multipy that 1 orange by 1000 to get 1000? If you wanted to make 1000 pieces of that 1 orange, wouldn't you divide it? |
| Russell120 | quote: This is the way electricity electrocutes you. It can also explode (the dreaded arc fault). The arc fault kills you through its shock wave (much higher pressure on one side of your body then the other), burns (the temperature of the plasma jet gets somewhere in the 12,000 degree range), the photons can blind you, and the bang can deafen you. Falls (from ladder, etc.) after electrocution or blast also injure a number of people each year. |
| iwire | quote: You can not think about them as separate items. Take a welder for instance the open circuit voltage is about 70 volts the amps may be 250. With dry skin I can touch this without feeling a shock. Wet the skin and you may very well get whacked. The current will fry things but it also takes enough voltage to over come the resistance of your skin and or boots etc. There are no absolutes when it comes to electricity killing you, some have died from small amounts of power some will live through a large amount of power. I have survived being hung up on 277 volts with more available amps then I care to remember. This ran from one hand to the other for what seemed like a long time, the fall from the ladder probably saved my butt. This does not make me special just lucky (and stupid) tomorrow a 120 volt shock from my hand to me elbow may take me out, you just can't tell. |
| JimmyDee | quote: Think about this for a bit. Just how many amps are flowing in an open circuit?  (Hint, The same number of amps will be flowing if the welder is set for 50 amps or 400 amps on an open circuit)Its amps that kill, but it takes the volts to push the amps to the killing level. Jim |
| iwire | quote: OK you got me there  let me rephrase, when I try to close the circuit with my dry skin the resistance of my skin will not allow current to flow at 70 volts. Get my skin wet and I most likely will be able to close the circuit enough that I will get whacked.This electricity stuff is tough.
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| JimmyDee | Yep, that be much better. Jim |
| stedder | So I guess I was lucky when a 730 v ballast (fractional amperage) got me through my hands and grounded out through my (sweaty) knee to the coke machine I was leaning against. Good thing it was only a two foot ladder (not far to fall) Of course this extra knee I have and the inside out sunburn I had is / was a good reminder (new code change) to disconnect before ballast changes hits home. Thanks fer listnin'
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| JimmyDee | Either lucky or God said, "not yet". The hot feed is the first one to cut and the last one hook up. That will keep you alive a lot longer. That is if you are going to flagrantly disregard the OSHA rules by changing them hot. Jim |
| dragonelectrician | quote: Raising the voltage from "1 or 2 volts" up to 50 kv would not lower the amperage to the micro-amp range, it would increase the amperage. I=E/R therefore: "50,000 volts"/R would yeild a much higher amperage than "1 or 2 volts"/R |
| dragonelectrician | Noticing the debate that went on for a while regarding the conversion formula from amps to milliamps, hopefully the following will end the debate: It is true that mathematically if you simply multiply 1 amp by 1,000 you will end up with 1,000 amps or 1 kiloamp; however this is not a conversion you are actually changing the value of of what you have, as opposed to a conversion when you are mantaining the same value, but changing the unit of measure you are using to express that value. The conversion formula of x amps*1,000 to yield 1,000 mA that has been mentioned is actually a simplified way of looking at dimensional analysis (a "formula" used in chemistry to convert values) in the first parenthesis you have your current value with an implied "1" as the denominator and the second parenthesis you have the conversion value (the actual ratio of the two "units of measure" being converted: in this case there are 1,000 mA for every 1 A which is where we get (1,000 mA / (per) 1 A) or, when multiplied out (x A * 1,000 mA)/1 A The "units of measure" cancel each other out as if they were numbers therefore the A in the numerator and the A in the denominator cancel each other out leaving the mA in the numerator and only a "1" in the denominator as follows: Which is the same as saying 1,000 times "x" number of amps = mA This is much easier to express on paper, but I believe most everybody should get the gist of it |
| lctrc789 | Voltage itself may have little to do with wether a shock merely startles you or it is fatal.. We all know that shock occurs when electric current flows through your body. The three factors that determine the extent of the injury is : The amount of current (amperage) the flows through your body, The path the currnet takes, and of course the lenght of time it travles. Less than 1/2 milliamp no sensation 1/2 to 2 milliamps Threshold of perception 2 to 10 milliamps muscular contraction 5 to 25 painful shock (may not be able to let go) Over 25 Could be violent muscular contraction 50 to 100 Ventricular fibrillation over 100 paralysis of breathing. Again remeber that the higher the voltage the lower the amps , but usually higher voltage will carry eneough current if it goes through you in the path of the heart that it could boil your blodd and kill you instanly. The amount of current which can be fatal to anyone is very small. The amount of current that flows through the body depends on the amount of the voltage pushing it through the conductor as well as the amount of resistance that the current has to overcome. We all also know that a milli amp is one thousandth of an amp. |
| stedder | I know Jimmy, hot first out and ground first in but when I went to replace the pans WOWooooowwwuggfhuhhhh. (Thats kinda' the sound I made commin' off the ladder.) (ballast shorted to frame) |
| JimmyDee | quote: Don't know how I missed this post but I'll stand with my original statement. Lets say your battery was capable of putting out 1 amp at 2 volts. What you are saying, even if the amperage stayed the same and did not increase is, that at 50 kv, you would be producing 50,000 watts of power from a small battery. Just not going to happen. Watts in - efficiency will = watts out. Jim |
| dragonelectrician | Sorry about the whole thing with the voltage and amperage with the tazers JimmyDee, I had just been doing something else with E=IR and for some reason or another was thinking along the lines of fixed resitance when I should have been thinking along the lines of the fixed output of the battery in terms of Power. |
| PEI | Just a few random thoughts,... The Taser scrambles/confuses your neurons (electrical pathways) in your body that are transmitting information, thought, touch, motor control etc. It does not normally effect your heart. When I was in college, we were told that the body is roughly 2000 ohms. If you have ever seen a curve of amperage graphed to impact on the body, you see that there is a high occurrance of death around 25 milliamps up to about 100 when passed thru the heart. We all understand why the low amperage will interrupt the AV nodes signal to the heart and stop proper muscle contraction, but why if it is over a 100 mA does it not necessarily kill you. Well it turns out, you tighten up so much, that your chest holds your heart still until the power is released. At that point your heart may actually restart - down side is the rest of you is not in real good shape. If you find this inconceivable, then explain how people survive lightning strikes. |
| Ryan_J | I think that would also explain why de-fribulation is the cure for electric shock in many cases. It seems strange...a person gets shocked, so the fix is to shock them again, only this time the doctor does it!
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| powerup | Devide by 1000 or multiply by .001 1 amp X .001 = 1000ma |
| Wirenutz | you fellas are stuck on volts & amps here, yet there is more to the physics of 'lectrickity than that consider frequency for a momnet the higher the frequency, the greater the skin effect of any given conductor what is considered dielectic may no longer an absolute as it is within our 60 hertz mindset ~W~ |
| powerup | Correct on the frequency. AC kills much easier than DC. Edison used this in advertising when trying to shut out the AC system. |
| Wirenutz | the was a pix on the net, dang if i can find it now. in one of the Tesla clubs iirc had some dude playing Zeus, lightning bolts shooting out his fingertips....high freq x millions of volts resulting in voltages literally on his skin surface don't think i'll be trying it any time soon though, they really don't make enough budwieser yanno....  ~W~ |
| sparkie2170 | Heres the deal, It dont feel good! I had a 71 Jeep Wagonner, all steel, I had a friend crank it while I checked for spark from an Accel Super coil. Needless to say, I had the lead in one hand, and my other hand on the grill! Yup, it had spark and knocked my butt to the ground.
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| JimmyDee | You got about 50k volts with no amperage. Add a few amps to that and you would have stayed on the ground. Jim |