Electrocution - how does it work?

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This is my first post, I hope its okay to start a thread on this. I did search but only found tidbits of relevant stuff in threads more focused on how not to get electrocuted while welding. My curiosity and theme of this thread is about electrocution in general, even outside of welding.My confusion on this began a year ago when I did a level 1 (3 total levels in the UK) electrical installation course. The instructor told us a current of 200milliamps is lethal. This (excuse the pun) was a shock, and I still do not understand it. Arent typical cellphone chargers these days at least 2000milliamps? Googling around I found this information about electrocution from a reputable source (ohio college) https://www.asc.ohio-state.edu/physi...l_current.htmlWhich echoes the same sort of thing the tutor told us but in more detail;For currents above 10 milliamps, muscular contractions are so strong that the victim cannot let go of the wire that is shocking him. At values as low as 20 milliamps, breathing becomes labored, finally ceasing completely even at values below 75 milliamps.
Reply:to avoid electrocution always make sure the machine is grounded properly.i.u.o.e. # 15queens, ny and sunny fla
Reply:Electricity has to travel through your heart to kill you. As in from one hand to the other. Usually when someone gets shocked it's from a hand to a foot. When I was a kid an old timer told me that it's smart to keep one hand in your pocket when poking around electrical connections. And dc is more dangerous than ac because it grabs you vs throwing you. Ever notice birds sitting on high voltage power lines with no issues? That's because they're not grounded.
Reply:

Originally Posted by henry42

Ever notice birds sitting on high voltage power lines with no issues? That's because they're not grounded.
Reply:The electrical resistance of your body limits current to safe levels when you come in contact withlower voltages. Higher voltage, same body resistance =higher current.Miller a/c-d/c Thunderbolt XLMillermatic 180 Purox O/ASmith Littletorch O/AHobart Champion Elite
Reply:A few milliamps connected to the lobes of your heart might kill you.   Through your hands to a ground you probably won't even know it's there simply because the body is not all that good of a conductor.  Digital devices with 5 volts and milliamps of current won't get very far unless you are standing in the shower with a tight grip on a plumbing pipe.Higher voltage and higher frequency will help the flow through your body.  Like the spark jump on a Vandegraph generator high voltage will help carry low amps through low conductivity areas of your body, such as gloves or the skin on your hands and the soles on your shoes.   I have heard of industrial accidents where repairmen got careless and forgot to turn off power before grabbing a component with 600 volts and having their fingers burned off/blown off as well as holes in the soles of their shoes and feet.     https://reference.medscape.com/featu...rical-injuriesBut digital devices with 5 volts and milliamps of current won't get very far unless you are standing in the shower with a tight grip on a plumbing pipe.  When working on digital devices we wear a protective strap to protect the device from the electrical charge inside of our bodies, not the other way around.Century buzzbox that I learned on 40+ years ago (was Dad's)Crappy Century 110volt mig 70 amp pigeon pooper.Lincoln Idealarc TIG-300
Reply:

Originally Posted by treefondler

The thought about grounding already came to mind and I tried to get tutor to explain it but I didn't manage to get a thorough enough explanation to understand. He said something along the lines of it not making any difference at all whether a person welding was grounded or not. That the electricity only wants to travel between the two welding cables and no where else. That it would not decide to take a short cut to ground through our bodies because it has no inclination to go to ground, that it goes to the other terminal.We all know that in warm & poor countries, the kind of people who weld rarely even own a pair of shoes. And they definitely do not wear gloves. If the current had any tendency to go to ground, surely the operator would be getting electrocuted on a daily basis?
Reply:speaking as a former paramedic who has treated a whole bunch of electric shock victims, electricity kills you in one of two ways. Electricity can disrupt the rhythm of your heart causing something called ventricular fibrillation, which is a form of cardiac arrest. The other way that electricity can kill you is by burns. I once picked up a kid after a hurricane who grabbed on to a downed high tension line. Burnt his arm and both legs off right on the spot. His heart never stopped and he never lost consciousness. Higher voltages are always more deadly that lower voltages and AC is always more dangerous than DC given the same amount of current. Most of the patients I treated after electrocution were awake but badly burned. I only had one that was in cardiac arrest from the shock.https://www.brighthubengineering.com...ck-comparison/https://www.lincolnelectric.com/en-u...hock-faqs.aspxMiller Multimatic 255
Reply:Your skin is a natural insulator that is good for up to 50volts, give or take.  That’s why a lot of telecom power requirements are for 48 volts; it’s below the typical body’s resistance threshold.Miller Trailblazer Pro 350DMiller Suitcase MIGMiller Spectrum 2050Miller Syncrowave 250DXLincoln 210MP
Reply:Good to know. Hi voltage starts at 65 volts depending on who you ask
Reply:It takes amps and volts to kill usually. One without the other isn't as bad. High amperage would be like welding leads or car battery lots of amps but little volts. Then the high tension sparkplug voltage has lots of volts but lacks amps. Combine the two though and things gets lively.
Reply:

Originally Posted by Louie1961

speaking as a former paramedic ...
Reply:I have been zapped by the HF start using TIG in my hot sweaty tropical environment, enough to throw the torch across the shop.....it has happened when stick welding also, when my gloves were wet and resting on the part being welded. Shocking experience.
Reply:

Originally Posted by scsmith42

Your skin is a natural insulator that is good for up to 50volts, give or take.  That’s why a lot of telecom power requirements are for 48 volts; it’s below the typical body’s resistance threshold.
Reply:

Originally Posted by Louie1961

electricity kills you in one of two ways. Electricity can disrupt the rhythm of your heart causing something called ventricular fibrillation, which is a form of cardiac arrest. The other way that electricity can kill you is by burns.
Reply:Also more people are electrocuted by household voltages than high voltages for several reasons including household voltage is more commonly contacted and often by unqualified persons. Higher voltages are usually dealt with by trained persons.Miller Challenger 172Miller Thunderbolt AC/DC 225/150Miller Maxstar 150 STLVictor 100CVictor JourneymanOxweld OAHarris O/ASmith O/A little torchNo, that's not my car.
Reply:This last summer we lost power to the house, turns out that a feline type creature ran up the pole that supplies our house & the neighbors place, got accros the lugs on the transformer, we found the hollow burned to a crisp cat a month later when I was picking up all the scrap metal I bought from her, as it turns out the feline belonged to a neighbor down the road and they had been looking for it & finally concluded it got coyote'd, owl'd, bob-cat'd or mountain lion'd, but nope there it lay in all its radiant after life.IMPEACH BIDEN!NRA LIFE MEMBERUNITWELD 175 AMP 3 IN1 DCMIDSTATES 300 AMP AC MACHINEGOD HELP AMERICA!“Freedom is never more than one generation away from extinction.We didn’t pass it to our children in the bloodstream".RONALD REAGAN
Reply:A few years back I saw a hawk go after a squirrel on a power pole crossbar and get 2 phases of 15KV lines. Flashbulb with a shower of feathers. The sonic boom got the squirrel.
Reply:I recall my dad telling me about a guy that got electrocuted while waxing his car with a 120v polisher. Back in the day tools were not double insulated as they are today. They were made of metal and a reversed neutral could cause the body of the tool to be hot.  He stepped in a puddle of water from washing the car and that was his end. Thankfully tools are safer today.
Reply:We had an electrician here back in the 60' got into some 480 IIRC, he lost both arms below the elbow, He adjusted well and blew his settlment on a pretty wild 427 or 454 Chevelle SS, and radicalized the crap out of it, last I heard he was doing rehab for fellow amputees , had none of his settlement money left, his wife had left him .....I i would see him at the bar occasionally shooting pool, he was pretty damn good with the hooks.IMPEACH BIDEN!NRA LIFE MEMBERUNITWELD 175 AMP 3 IN1 DCMIDSTATES 300 AMP AC MACHINEGOD HELP AMERICA!“Freedom is never more than one generation away from extinction.We didn’t pass it to our children in the bloodstream".RONALD REAGAN
Reply:In the worst conditions the human body is a poor conductor. Lets go to the basics:Voltage is electrical pressureAmperage is electrical currentWattage is volts times amps. A low voltage source will not have enough pressure to push much current through human flesh. Shock is always through a person. It takes two points of potential. If the path is primarily through non vital organs, it may not kill despite tremendous current (amps). Personally I have experienced voltage up to 240, and much higher instantaneously. The worst would have measured 120 from right to left hand. I was unable to let go for an extended period, maybe two minutes. I suffered severe muscle strain in forearms, but little else. I work with live power too often. I may not be giving proper respect, but don't worry much about incidental shocks from 240 volt supplies. The 480, on the other hand, I have nightmares about. You treat that like a rattle snake. Here, we ground the center tap of 240, so the most common shock is to ground of 120 volts.In WYE connected three phase 480 Volts, to ground is 277.Use care, follow safety rules. You'll likely get a few shocks in your life, but live.An optimist is usually wrong, and when the unexpected happens is unprepared. A pessimist is usually right, when wrong, is delighted, and well prepared.
Reply:Those of us who work with it every day tend to get complacent and or lazy, we work with it every day which increases the odds of electrocution immensely. I have to drive it into the heads of my workers, don't be lazy, shut it down. Why risk your life to save a few minutes? Very, very few if any at all, legitimate reasons to work it live.Miller Challenger 172Miller Thunderbolt AC/DC 225/150Miller Maxstar 150 STLVictor 100CVictor JourneymanOxweld OAHarris O/ASmith O/A little torchNo, that's not my car.
Reply:I've touched a live 240V terminal a couple of times in my life, accidentally. Luckily always with dry skin, so I got a good belt of a shock but not enough current to cause harm.That's true 240VAC to ground, not centre tapped. I've never touched a 415v 3 phase connector yet, touch wood. Although each phase is still just 240V. Would be incredibly unlucky to grab a second phase at the same time.
Reply:The worst shock for me was the neutral of a 277 vac lighting circuit.  For me, things slowed down and I could feel every one of those 60 cycles.  My whole body went rigid until my helper jerked the wire out of my hand.  Every muscle in my body hurt for the next week.Owner of Fast Leroy's Bar and GrillLiquor up Front, Poker in the Rear
Reply:

Originally Posted by Munkul

I've touched a live 240V terminal a couple of times in my life, accidentally. Luckily always with dry skin, so I got a good belt of a shock but not enough current to cause harm.That's true 240VAC to ground, not centre tapped. I've never touched a 415v 3 phase connector yet, touch wood. Although each phase is still just 240V. Would be incredibly unlucky to grab a second phase at the same time.Voltage seeming to be lower can kill. 120 volt sources kill sometimes. The electrical inspector who runs code refresher courses tells of an electric range in New Hampshire. Appliance delivery people installed a cord on a new range. The strain relief clamp supplied with these cords never work. They discarded the clamp, installed the plastic insulated cord through the sharp edged hole in sheet metal with nothing to protect the cord from being damaged. The ground strap, a copper ribbon supplied with all new ranges was not used either. The range was pushed against the wall pressing the sharp edge into the soft insulation. The family used the range over a year without incident until a plumber was getting up after working under the sink. He must have steadied himself touching range with one hand, the sink with the other. He died. 120 volts was enough to kill him.An optimist is usually wrong, and when the unexpected happens is unprepared. A pessimist is usually right, when wrong, is delighted, and well prepared.
Reply:Some people have lower skin resistance than others, and also some people take less current through the heart to kill them. There's no fixed rules.the Interweb tells me that "people have died from as little as 42v DC"
Reply:

Originally Posted by Munkul

Some people have lower skin resistance than others, and also some people take less current through the heart to kill them. There's no fixed rules.the Interweb tells me that "people have died from as little as 42v DC"
Reply:

Originally Posted by G-ManBart

I went through a basic electrical school for work and one of the instructors set up a 115V AC circuit that we all had to touch and try to get the breaker to trip.  This was after talking about how little amperage can potentially be deadly.  Some folks could make the breaker trip the instant their finger touched the post, and others couldn't get it to trip at all.  The instructor would put his finger on the post and talk for a minute with nothing happening....crazy.  I didn't think about it at the time, but I now wonder if a lot of it was the shoes/boots we were wearing.  Needless to say, I try not to electrocute myself regardless of footwear!
Reply:

Originally Posted by Willie B

Voltage seeming to be lower can kill. 120 volt sources kill sometimes. The electrical inspector who runs code refresher courses tells of an electric range in New Hampshire.
Reply:Electrocution - how does it work?It's shocking!!

6 Miller Big Blue 600 Air Paks2 Miller 400D6 Lincoln LN-25's4 Miller Xtreme 12VS2 Miller Dimension 812 4 Climax BW-3000Z bore welders Hypertherm 65 and 85Bug-O Track BugPair of Welpers
Reply:

Originally Posted by Kelvin

Never heard of a 120V electric range. The ones I've seen were 240V on a 20 or 30A breaker.When I was a toddler, I reportedly tried to "start up" our 240V electric range by inserting a car key into one of the (missing) buttons on the front.

My mom walked into the kitchen right as it happened and she said it threw me clear across the kitchen and blackened the hair on my whole arm...My dad said he once grabbed a fistful of 440 or 550VAC Buss bar once in a factory...I guess we're just lucky.
Reply:Old ranges had clocks, timers and oven lights that were 120vac. Some even had back lights and fans. Neutrals and grounds back then were considered wires that you should have at least 'one' of but didn't really need both. Galvy pipes coming in from the street or well, meter base ground was a piece of galvy pipe driven in 2 feet with a hose clamp clamp connection, the well house had hot/hot and the casing was the ground and a 120vac light if not two. Wasn't unusual to get a tingle if you stirred a pot on the stove and touched the sink at the same time. You'd get a tingle if you leaned on the running washing machine while pulling clothes out of the dryer."The things that will destroy America are prosperity at any price, peace at any price, safety first instead of duty first, the love of soft living and the get rich quick theory of life." -Theodore Roosevelt
Reply:Dependz !
Reply:[QUOTE=Sandy;8723084]Old ranges had clocks, timers and oven lights that were 120vac. Some even had back lights and fans. Neutrals and grounds back then were considered wires that you should have at least 'one' of but didn't really need both. Galvy pipes coming in from the street or well, meter base ground was a piece of galvy pipe driven in 2 feet with a hose clamp clamp connection, the well house had hot/hot and the casing was the ground and a 120vac light if not two. Wasn't unusual to get a tingle if you stirred a pot on the stove and touched the sink at the same time. You'd get a tingle if you leaned on the running washing machine while pulling clothes out of the dryer.[/QUOTYup, the good old days. Grandma kick started her Maytag on the back porch. No one in rural America knew there was a code. My grandmother's house was wired by my uncle. He was a sixth grade electrical trainee. They gave him a battery, a paper clip, and a bulb for a flashlight in sixth grade. He firmly believed that was all he needed. He bought a reel of lamp cord, and twenty "cleat receptacles" You removed one screw, split it in half. Nailed the back to the wall with cord passing through. Put the front on, secure it with the screw. You had an outlet. Probably  feet of lamp cord plugged into that one outlet. She only burned one bulb at a time.An optimist is usually wrong, and when the unexpected happens is unprepared. A pessimist is usually right, when wrong, is delighted, and well prepared.
Reply:

Originally Posted by Willie B

The grounded center tap in USA single phase systems I believe to be pretty much universal limits the one conductor to earth voltage to 1/2 the total transformer voltage. The damaged insulation on the conductor I mentioned energized the ungrounded frame of the range. The second point of contact for the plumber was the grounded sink. One leg to earth 120 volts.
Reply:

Originally Posted by Kelvin

Oh -- now I get what you're saying. Just one conductor got pierced so it was 120V between that conductor and ground. But probably 30A of 120, assuming it was a 240V/30A circuit?So I guess my Mom lied when she told the story. Or maybe you're suggesting I'm lying...not sure. You can connect a battery to a dead frog's amputated leg and it'll twitch. I wouldn't be surprised if an AC shock might make muscles contract or extend violently enough to make someone "throw himself" across a room...or at least make his hand clench around the conductor. Or maybe it's simply the person recoiling from the arc flash and POP violently enough to "throw himself across the room." Maybe it ain't physics but physiology.Or maybe "hundreds" of people are mistaken ... or lying ... and you alone are correct.As for the physics, I've seen where transformers have exploded. Lots of heat liberated when a lot of power goes to ground. I suspect someone who touched a high-voltage line could be "thrown across a room" by the steam created from their bodily fluids by all that heat...though they probably wouldn't live to tell the tale.


Reply:One thing about that 48vdc on the phone line... it goes ac 20cps at ~90acv when ring comes on


Reply:

Originally Posted by ronsii

One thing about that 48vdc on the phone line... it goes ac 20cps at ~90acv when ring comes on


Reply:Yeah Willie, the CO's around here still have plenty of lead acid banks and good ole solid copper buss bars running around the CO's overhead... in fact every once in a while a worker with a piece of EMT over his shoulder finds out just how AMPS work  

kinda like your tape... only louder and brighter

I've been around telco stuff since I was a kid

either ripping apart equipment or cobbling it together to make something better...I still have a few ringer cranks around here somewhere... always fun when you're a kid and the contest was to see how long one of us could hold onto the terminals while another kid cranks it!!!!


Reply:

Originally Posted by ronsii

One thing about that 48vdc on the phone line... it goes ac 20cps at ~90acv when ring comes on


Reply:

Originally Posted by bigb

Yes and that will cure one of the habit of stripping the wires with your teeth!
Reply:ARC is what usually kills. ARC is not electricity from the power source. ARC is a very high voltage reaction to a power source current, and subsequent breakdown of an air capacitor or other dielectric substance breaking down. If you have been near a start capacitor of a five horsepower motor, when the start cap breaks down and blows, you know that there must be very high voltage created. The magnetic field of the motor and the ARC are transmitted by the magnetic field a good distance away. You can have light in your head, and electrical sounds and effects occur in your head from such an accident even twenty feet or more away. Most today are not taught about air capacitors because it leads to weapons of mass destruction as Tesla talked of and built. And the military has obtained used and lost or covered up over the decades. 1.5 volts will travel miles through the air. It travels by creating a capacitor, the air being the dielectric. But again, the radio weapons are seen as a reason for handing out assault rifles to the community to keep their minds off radio weapons. They went so far as to reverse Benjamin Franklin's exact markings of electricity, to confuse and complicate electricity. Just as England and France had done centuries before. While Benjamin Franklin had paid for and installed working lightning rods up and down the eastern seaboard in the colonies, England was still sending young boys to the church bell towers to ward off lightning. After England could no longer hide Benjamin Franklin's exacting work, they gave him the Copley award and did away with the French scientist Du Fay's silly two-particle theory of electricity. Later our "modern" colleges brought Du Fay's crazy theory back and claimed Benjamin Franklin could not have known which way electricity was flowing. Yet Benjamin Franklin created the test to tell which way electricity is flowing, using pointed and flat electrodes. He found that if the electricity was flowing to the pointed electrode from a flat electrode that it would melt the pointed electrode. If the electricity were flowing from the pointed electrode to the flat electrode, it would leave the pointed electrode intact. The human body conducts electricity rather well — more than enough to light an incandescent bulb. ARC is very dangerous when you are holding a piece of metal and are not well connected to the earth. Like when you are standing in a puddle of dielectric water, or if you fall back on your heels, you change the size of the capacitor your body creates with the earth. As you become a smaller and smaller capacitor, you, the plate of the capacitor fills more rapidly and can cause your heart to stop by the sudden change in voltage to your body. The reason is that any white spark is capable of delivering thirty thousand volts. However, with no amperage, while you are well-grounded, it is rather harmless like static electricity. But just like standing in water and receiving a static shock can kill you, if you are holding a piece of metal hit by the ARC. Falling back on your heels while holding a welding rod that is hit with an ARC, and reciprocates with an ARC of its own can also kill you. The reason is you become a certain sized capacitor that is capable of utilizing the voltage to create a sudden polarity differential in your body. Of course, being well-grounded or connected to two conductors can kill as well, especially over time. Sincerely, William McCormickIf I wasn't so.....crazy, I wouldn't try to act normal, and you would be afraid.
Reply:

Originally Posted by William McCormick

ARC is what usually kills. ARC is not electricity from the power source. ARC is a very high voltage reaction to a power source current, and subsequent breakdown of an air capacitor or other dielectric substance breaking down. If you have been near a start capacitor of a five horsepower motor, when the start cap breaks down and blows, you know that there must be very high voltage created. The magnetic field of the motor and the ARC are transmitted by the magnetic field a good distance away. You can have light in your head, and electrical sounds and effects occur in your head from such an accident even twenty feet or more away. Most today are not taught about air capacitors because it leads to weapons of mass destruction as Tesla talked of and built. And the military has obtained used and lost or covered up over the decades. 1.5 volts will travel miles through the air. It travels by creating a capacitor, the air being the dielectric. But again, the radio weapons are seen as a reason for handing out assault rifles to the community to keep their minds off radio weapons. They went so far as to reverse Benjamin Franklin's exact markings of electricity, to confuse and complicate electricity. Just as England and France had done centuries before. While Benjamin Franklin had paid for and installed working lightning rods up and down the eastern seaboard in the colonies, England was still sending young boys to the church bell towers to ward off lightning. After England could no longer hide Benjamin Franklin's exacting work, they gave him the Copley award and did away with the French scientist Du Fay's silly two-particle theory of electricity. Later our "modern" colleges brought Du Fay's crazy theory back and claimed Benjamin Franklin could not have known which way electricity was flowing. Yet Benjamin Franklin created the test to tell which way electricity is flowing, using pointed and flat electrodes. He found that if the electricity was flowing to the pointed electrode from a flat electrode that it would melt the pointed electrode. If the electricity were flowing from the pointed electrode to the flat electrode, it would leave the pointed electrode intact. The human body conducts electricity rather well — more than enough to light an incandescent bulb. ARC is very dangerous when you are holding a piece of metal and are not well connected to the earth. Like when you are standing in a puddle of dielectric water, or if you fall back on your heels, you change the size of the capacitor your body creates with the earth. As you become a smaller and smaller capacitor, you, the plate of the capacitor fills more rapidly and can cause your heart to stop by the sudden change in voltage to your body. The reason is that any white spark is capable of delivering thirty thousand volts. However, with no amperage, while you are well-grounded, it is rather harmless like static electricity. But just like standing in water and receiving a static shock can kill you, if you are holding a piece of metal hit by the ARC. Falling back on your heels while holding a welding rod that is hit with an ARC, and reciprocates with an ARC of its own can also kill you. The reason is you become a certain sized capacitor that is capable of utilizing the voltage to create a sudden polarity differential in your body. Of course, being well-grounded or connected to two conductors can kill as well, especially over time. Sincerely, William McCormick
Reply:Well.... that's a whole load of horse-crap.
Reply:You forgot to mention the inverse ratio of magnetism on the flux capacitor.An optimist is usually wrong, and when the unexpected happens is unprepared. A pessimist is usually right, when wrong, is delighted, and well prepared.
Reply:Willie, I am just SHOCKED that you know about that!!!!!  I figgered you for a more conventional guy probably sticking with the tesla models of inverse magnetic reactance.
Reply:

Originally Posted by William McCormick

The human body conducts electricity rather well — more than enough to light an incandescent bulb.
Reply:

Originally Posted by ronsii

Willie, I am just SHOCKED that you know about that!!!!!  I figgered you for a more conventional guy probably sticking with the tesla models of inverse magnetic reactance.
Reply:

Originally Posted by Munkul

Well.... that's a whole load of horse-crap.