Electrocution - how does it work?

[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. 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.

[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"

[G-ManBart]

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"

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!

[Willie B]

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!

Don't get hung up on footwear. Most low volt electrocutions are hand to hand, (the most direct route through the heart).
I can't imagine what your instructor was using as a circuit breaker, maybe 1/2 amp?

Most people don't conduct well. Years ago at lunch I was with a group of construction workers. Conversation went to why some people feel real pain when shocked by 10 volts, others can't feel 100 volts. I gave my guess, others had their guess. We tested resistance thumb to thumb with a basic ohm meter powered by a 9 volt battery.

My guess was not disproven by the test. I believe flesh is a poor conductor in general, but skin is a much worse conductor. The two least conductive people that day were the tile setter, a VERY sexy young lady who was vegan, and consumed NO sodium. Next least conductive was the plumber with thick callouses, dry skin, he was on a no salt diet. I was most conductive. I consume too much salt, and in summer guzzle large volumes of water.

My father tested industrial circuit breakers. They used a variable resistor; a plastic barrel full of salt water. A conductor connected to a copper plate at the bottom. A second plate was moved to vary resistance. Clean water wouldn't conduct enough to work. Salt was important. I believe in people water and salt, maybe other electrolytes factor.

Certainly current kills if a sufficient current passes through the heart. The body survives great current if the path is not through the heart.

Other forms of electrocution have been mentioned here; burns ,and paralysis. The harbor deaths are typically about damaged equipment. Some low bid contractor installs electrical equipment for boats in a harbor. They do a half job of protecting from damage. They pay off an ethically challenged inspector, or he's just too busy to take the time to look that day.

5 weeks later that equipment gets bumped by a boat. Nobody notices the damage, or nobody follows up after noticing damage. Months go by. Nobody fixes an obvious hazard. One hot summer evening the people aboard a given boat are missing the one cautious person. Everybody gets into the drug of their choice. Cindy Lou Who is silly drunk, the crew gets macho, they throw Cindy Lou into the oil/feces fouled harbor. She does what we all would, she climbs out.

The water is charged with a damaged power source, the ladder is grounded. Cindy can't climb in her inebriated/electrocuted condition. Maybe she can't breathe. She dies.

[Kelvin]

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.

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.

[ExpatWelder]

Electrocution - how does it work?



It's shocking!!

[Willie B]

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.

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.

As for the "Thrown halfway across the room" is something I've heard hundreds of times. Nothing in physics suggests that is possible. My "trick" as a child was slipping a penny between plug and outlet. It made my mother furious! NO I didn't get a shock, and the explosion was mostly loud with very little violence. Cord, penny, and outlet were damaged.
If you found a live something with your car key, it likely conducted to the sheet metal of the stove. Likely left a black arc mark on the stove. It is unlikely you would have received a shock.

[Sandy]

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.

[Bonzoo]

Dependz !

[Willie B]

[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.[/QUOT

Yup, 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.

[Kelvin]

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.

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?

As for the "Thrown halfway across the room" is something I've heard hundreds of times. Nothing in physics suggests that is possible.

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.

[Willie B]

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.

It's a common exaggeration. Everybody does it. "There were a million mosquitoes". A 200 LB 35 year old man once told me the shock he got from a damaged phone cord (48 volts DC) "threw me across the room"

Certainly, people are thrown by arcs of lightning, or very large high powered arc blasts. You can jump to escape a shock. Muscles contract involuntarily, workers getting shocks of 1000 volts or more typically fall off ladders. A child making contact with the frame of the stove, and a live part inside might get a shock, but the available energy would not be sufficient to throw across the room. Through human flesh 0 through 3 amps, Arc to ground, maybe 200 amps. A heck of an event to a child, or his mother, not the epic explosion we hear about in high powered arc blast events.

An event occurred years ago; A three man crew were working in a factory in Bennington VT. In industrial situations management always pressure electricians too work live. If one electrician won't do it there is somebody else willing to do it. As I recall it was a 2200 volt set of buss bars. The electrician was connecting a bolt on terminal. He dropped his wrench. Two were wearing heavy protective gear.

No one received a shock. Injuries were burns, and concussion related from the explosion. Two were injured, one of them lost his eyesight, the third died from his injuries.

Calculations of available arc current are very complex. Most of us rely on power company engineers to provide these values. Most single phase systems are under 20,000 Amps. That would be at the transformer. The voltage loss factored in the length of current travel is far less than that. At household voltage, current through the high resistance of a human body is very low.

Yes, vaporization of copper is a major source of blast force. Copper expands by a multiple of more than 60,000. In the energy of high power arc blasts A cubic inch of copper expands instantaneously to a volume of 35 cubic feet.

[ronsii]

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

[Willie B]

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

Now you've got me thinking. For years we did the higher voltage work for the local phone company in all the surrounding towns until the employee we worked for retired. His replacement had electricians he liked.
The whole system was powered with a huge battery bank in 1969, the battery banks got progressively smaller over the years. All have been 48 volt systems. I never got into the inner workings of a phone system in the central offices. We had more involvement in battery chargers, inverters, lighting, heat pumps, AC, generators, ETC.

I don't remember any transformers, or inverters in the C O to provide AC, I would have guessed the ringer was powered by pulsating DC.

I once was being complacent. The "racks" in a central office were all equipped with buss bars at top directly powered from the battery bank. I measured with a 25' Stanley tape rule. I hit the buss bar, got showered with sparks, ruined the rule.

[ronsii]

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!!!!

[bigb]

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

Yes and that will cure one of the habit of stripping the wires with your teeth!

[ronsii]

Yes and that will cure one of the habit of stripping the wires with your teeth!

LOL!!!! so I guess I'm not the only one that found that was the quickest/best way to strip phone wire although I never found it to work on the old hard drawn drop wire

[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

[Willie B]

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

I am afraid!

[Munkul]

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

[Willie B]

You forgot to mention the inverse ratio of magnetism on the flux capacitor.

[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.

[Kelvin]

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

[Willie B]

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.

I'm smarter than I look. EVERYBODY tells me that....... I'd have to be.

[William McCormick]

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

What is it that you are not agreeing with?

Benjamin Franklin brought lightning into his basement with copper wire from the roof of his hillside home to a fireplace ball in the basement. The electricity would ARC to another fireplace ball that was grounded with a copper wire to a ground rod to the earth. He was then with later experiments able to turn the flow of lightning on and off by creating the first man-made open-air, transistor. He got a third fireplace ball and made an air capacitor by making two loops of copper sheet metal, an inner and an outer loop that was suspended by fine silk threads from the wooden floor joists, with an air gap between them. He attached a copper wire to the capacitor that connected it to the middle fireplace ball. He also connected a glass globe with copper wire to the capacitor that he would rub with his hand to charge the capacitor. When the capacitor was charged the lightning would not flow anywhere. if the capacitor was discharged the lightning would flow across the middle fireplace ball to the grounded fireplace ball. When he realized that you can steer or stop an ARC with an amount of electricity he created the lightning rod. No insulator stops electricity, only after the insulator is turned into a capacitor-dielectric and charges in a ramping voltage can it stop the flow of electricity.

You have to understand after we dropped the Hiroshima bomb which was an atomic-bomb, made from ordinary substances that are found commonly on farms and in industries, England and the U.S. openly announced that they would keep the secret of the atom and the atom-bomb from citizens. I guess they are no longer citizens or they do not know how the atom works anymore either. My point is that since then all that kids have learned in school is just make-believe nonsense. The graphic of the atom with the particles of electricity orbiting around the nucleus is propaganda to hide the actual working of the universe. The proof is there are no attraction forces in our universe only pushing forces. A vacuum does not pull anything into it, dirt is pushed by higher external air pressure into the vacuum. The pump in the vacuum compresses air and ejects the air back into the room. Magnets with opposite poles are pushed together once they create a flow of particles of electricity between them. Just like a short piece of hose will seem to be pulled to the same size hose flowing water out of it. The short piece of hose though is pushed to the hose flowing water by the external water pressure now leaving the short piece of hose. Gravity is a pushing force, to the planet. The rays leaving the earth repel less than the rays bombarding the earth.

When universal scientists tried to fight the new "modern" government scientists hired with mega grant monies to hide the atom, the universal scientists asked them to demonstrate this amazing new attraction force that was the basis for the Neutron's existence. Two modern scientists nodded to each other that they could demonstrate it, they got up and made hugging gestures around each other symbolizing particles pushing them together. So even they thought it would require a pushing force to hold sub-matter particles together. This would have been a hoot except they packaged the neutron and in 1973 made it mandatory to learn in school, meaning you could no longer teach the real universe in a publicly funded school. With taxes at the level they are at, all schools today even most private schools have to rely on federal funding. So they have to teach the agreed-upon counterintelligence curriculum.

When you mess up the basics everything else from there gets messed up and that is why the modern welder is labeled like a crazy person did it.

Sincerely,

William McCormick