Electrocution - how does it work?

[William McCormick]

It is true.

Sincerely,

William McCormick

[MetalMasher]

My experience with 'lectrical shocks consists thusly:

As a young Military Police private in the US Army in 1982, AIT, Ft. McClellan, AL, we all got to experience the venerable old field phones while out on our first bivouac. To "ring" the other end of the line, there was a small generator built into the field phone and a crank on the side to turn to generate the voltage to make the other end of the comm link ring. While in the process of laying the comm wire, apparently it was common practice for the Drill Seargent to hook up the pair of lines to the field phone and crank the thing as hard as he could, just to check and see if one of us meatheads happened to have the bare ends of the wire in contact with our bodies while were laying out the wire. I'm not sure what amount of current those things generate, but suffice it to say not only does it get your utmost attention, but you WILL holler and jump!

I've managed to zap myself with 120v outlets a few times over the years or accidentally touched various contact points in electric motors or wire junctions. It's not comfortable.

My worst one, and it was completely my own fault as I had a potentially deadly moment of gargantuan stupidity. I ran the wires from the main junction box that fed my house to my shop to add 240v (this was back when I was setting up my first woodworking shop). After stuffing the heavy gauge wires through too small of PVC conduit (that in itself was a major PIA), hooking everything up to the sub box in the shop and all that, it came time to finally hook the heavy wires to the lugs on the main box. In a moment of absolute sheer idiocy, I decided I could do that without deenergizing the main box (I didn't want to shut the entire house down, etc, etc). I figured it was two large lugs, straight forward and it would be simple enough to do. Wrong. I zapped myself. Enough such that my right arm was paralyzed below the elbow for several hours. It hurt like the dickens, but fortunately, no burns, no cardiac arrest, or other injuries.

Since that episode, I will go to extra lengths to ensure the power is off and whatever I am working on is definitely unplugged or otherwise not energized in any way. That shop wiring incident scared me, bad. I'm almost phobic about working with wiring, motors or anything electrical now.

When I first got my welder, I wondered about getting shocked with it and when others say it happens, it's always on my mind while welding. Although I've welded plenty with it since, any time I use it, that's on my mind. I always wear my leather sleeves/apron and gloves, I don't care how hot it is or that I have to take the time to put the gear on. I figure the gloves and sleeves will provide insulation from shock to some degree, and definitely they protect from the arc's UV and hot spatter (having a hot spatter glob drop onto you or down a piece of clothing is no fun either).

[William McCormick]

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.

Through both arms they say it is possible, it could be the amount of surface area that was in contact with the oven and the sink created enough amperage to do him in. Being a plumber his hands were probably wet as well which could turn him into a capacitor coponent with dielectric water on one or both hands between the power source, which can kill.

You can actually get 16 volts to register through your body from a 24 power supply, if enough of your body is in contact with painted cement, with the power source several feet away traverling through the cement. But all you have to do is lay on your back on the cement put the ground clamp of your ARC welder to metal that is either in the cement or a metal plate that is laying on the cement and then put your bare fingers on the ARC rod. You will feel it with wet hands for dry hands. I used to weld the bottom bars on handicap ramps so I am sure of that one.

Sincerely,

William McCormick

[William McCormick]

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.

If I touch my 120-volt house current and then touch the ground through an oscilloscope I register 165 volts through my body at 60 hertz, I can hardly feel it. However, my body is not hindering the AC current at all through ten million ohms. Video below I made this video nine years ago.



Sincerely,

William McCormick

[W9GFO]

Many years ago while working in a tropical (hot, humid) dive shop I was putting a 3 phase compressor back into service after maintenance. The electrical panel was in a different part of the building. The compressor was turning the wrong way so two of the wires needed to be swapped. I had opened the breaker and disconnected the wires - the connections were made above the box via copper clamps with thumbscrews. For some reason I had to go get something from back where the compressor was, I was only gone a minute. When I got back I reached up with both hands to finish attaching the wires (one hand on each wire, because you know, I am efficient that way) and immediately found myself stunned on the ground a few feet back from where I had started. It was a hellavu jolt but I was not hurt. Never figured out why someone had felt the need to close the breaker.

Something to remember, regardless of your past experience with getting shocked, you CANNOT develop an immunity to electricity. If you have survived some amazingly shocking experiences in the past it in no way means that you can't be easily killed by the next shock. I'll bet more than a few victims of electrocution felt that they could "handle" it based upon their past experiences.

[bigb]

Many years ago while working in a tropical (hot, humid) dive shop I was putting a 3 phase compressor back into service after maintenance. The electrical panel was in a different part of the building. The compressor was turning the wrong way so two of the wires needed to be swapped. I had opened the breaker and disconnected the wires - the connections were made above the box via copper clamps with thumbscrews. For some reason I had to go get something from back where the compressor was, I was only gone a minute. When I got back I reached up with both hands to finish attaching the wires (one hand on each wire, because you know, I am efficient that way) and immediately found myself stunned on the ground a few feet back from where I had started. It was a hellavu jolt but I was not hurt. Never figured out why someone had felt the need to close the breaker.

Something to remember, regardless of your past experience with getting shocked, you CANNOT develop an immunity to electricity. If you have survived some amazingly shocking experiences in the past it in no way means that you can't be easily killed by the next shock. I'll bet more than a few victims of electrocution felt that they could "handle" it based upon their past experiences.

That's the reason for LOTO. Whenever there are others on the premises you are in danger of the breaker being closed. Same on residential construction, if the framer trips a breaker he goes to the panel and flips them all. On residential if there is anyone else on the premises I remove the wire from the breaker, or remove the breaker from the panel. Or put a padlock on the door. I once was on a job where the idiot cabinet installer was trying to get the ceiling fan to work because he was hot and he closed the 50 amp HVAC breaker along with every breaker that was off. But you already know this, just putting this out there for anyone reading now and in the future.

[William McCormick]

That's the reason for LOTO. Whenever there are others on the premises you are in danger of the breaker being closed. Same on residential construction, if the framer trips a breaker he goes to the panel and flips them all. On residential if there is anyone else on the premises I remove the wire from the breaker, or remove the breaker from the panel. Or put a padlock on the door. I once was on a job where the idiot cabinet installer was trying to get the ceiling fan to work because he was hot and he closed the 50 amp HVAC breaker along with every breaker that was off. But you already know this, just putting this out there for anyone reading now and in the future.

I agree with you about assuming that one electrical shock is probably like another. Just because you survive the twenty or a hundred others does not mean the next one will not put you down like a mink being readied to give up his coat. I had my heart stopped once and I was so interested in what I missed that as I was going down for the full count I figured it out and started laughing at my own stupidity. Laughter evidently works just like coughing that they recommend if your heart stops. If you ever find yourself getting that tunnel vision with less and less light in the quickly narrowing tunnel try laughing through that remarkable chest pain. At worst you will die laughing.

Sincerely,

William McCormick

[William McCormick]

Many years ago while working in a tropical (hot, humid) dive shop I was putting a 3 phase compressor back into service after maintenance. The electrical panel was in a different part of the building. The compressor was turning the wrong way so two of the wires needed to be swapped. I had opened the breaker and disconnected the wires - the connections were made above the box via copper clamps with thumbscrews. For some reason I had to go get something from back where the compressor was, I was only gone a minute. When I got back I reached up with both hands to finish attaching the wires (one hand on each wire, because you know, I am efficient that way) and immediately found myself stunned on the ground a few feet back from where I had started. It was a hellavu jolt but I was not hurt. Never figured out why someone had felt the need to close the breaker.

Something to remember, regardless of your past experience with getting shocked, you CANNOT develop an immunity to electricity. If you have survived some amazingly shocking experiences in the past it in no way means that you can't be easily killed by the next shock. I'll bet more than a few victims of electrocution felt that they could "handle" it based upon their past experiences.

Hot and humid for me has always meant an enhanced electrical shock. I used to sand boats when I was younger and then later welded bow rails on boats in the water. I gained amazing deep respect for water and electricity. I also did HVAC and got shocks from things like a chimney while in the atic and wet as I was crawling between the chimney and what turned out to be a totally ungrounded AC system, air handler in the attic and condenser outside. "Hello!" is what I yelled out during the chimney incident I do not really know why.


Sincerely,

William McCormick

[William McCormick]

That's the reason for LOTO. Whenever there are others on the premises you are in danger of the breaker being closed. Same on residential construction, if the framer trips a breaker he goes to the panel and flips them all. On residential if there is anyone else on the premises I remove the wire from the breaker, or remove the breaker from the panel. Or put a padlock on the door. I once was on a job where the idiot cabinet installer was trying to get the ceiling fan to work because he was hot and he closed the 50 amp HVAC breaker along with every breaker that was off. But you already know this, just putting this out there for anyone reading now and in the future.

Many years ago I was working on a construction site and it was a mess. The temporary panel was located in a puddle. They ran Romex and extension cords throughout the eight-story building. We were coring through eight-inch cement with six-inch diamond core bits. Every now then we would blow a breaker. So I go down to this little shack in a puddle, standing in the water against my better judgment in almost total darkness, I start throwing breakers. I heard a loud pop up on the third floor approximately, I was really getting nervous, I had one hand on a good-ground so I felt pretty sure I would survive. I throw the next breaker and I hear what sounds like a stick of dynamite and I see light in the panel and felt the polarization. I threw one or two more and someone yelled that is it. As I am going up the stairs I am looking at the temporary lightning that I saw on the way down. The bulbs were all gone. I did some experimenting later on and I think that the neon-lighted extension cord ends caused that. I just hope no workers disappeared with the bulbs.

Sincerely,

William McCormick

[RoadTrip]

- On stick machines in general, the electrodes are changed extremely frequently without turning the machine off. Our tutor never wears gloves even so does this bare handed.
- Also in general welding, we hold workpieces in our hands while tacking. (Barehanded for some people) and we do not get shocks.

Thanks for submitting this treefondler (disturbing name). I joined this forum to find out about those same concerns.

[MetalMan23]

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.

Obviously he's never welded with wet gloves, or standing on wet sand, or pretty much welded at all.

[12V71]

Obviously he's never welded with wet gloves, or standing on wet sand, or pretty much welded at all.

BTDT repairing irrigation pipelines. I usually got it through my shoulder laying in mud changing a rod.

[Willie B]

Obviously he's never welded with wet gloves, or standing on wet sand, or pretty much welded at all.

Earth ground is not intentionally part of the welding circuit. Unintentional ground connection is pretty common. A table might have a grounded grinder laying on it. You might weld with the weldment on the ground. Electrons seek to be returned to the other welder lead, and they easily can do so through your body.

Wear gloves welding, long sleeve shirt, use thought about current path. and know that sooner or later you'll fail to anticipate, and get a tingle. Odds are you'll survive with no injury.

[Welder Dave]

BTDT repairing irrigation pipelines. I usually got it through my shoulder laying in mud changing a rod.

I repaired an irrigation line on a golf course and the ground was wet. I put my hand down with a welding glove on to get in the hole and got a buzz. My welder was idling. It wasn't real strong but you definitely felt it.

[lotechman]

I had to weld down steel decking on a roof during a rainstorm. Crazy thing to be asked to do it but I was young. I put on a pair of rubber gloves then my soaking wet welding gauntlets. The water was running down my arm into the rubber gloves and I could feel that my fingers were immersed in water. No shocks and it amazes me even today thirty years after.
I took a physics course and the prof in this college was making small talk as I took extra time on my lab. He casually mentioned that he repaired radar sets in England during WW2. The procedure was to power up the radar chassis and then check voltages and troubleshoot. You did this sitting on a metal stool. The bench was all metal and grounded. He said that at all times your arms were to be resting on the edge of the bench. He then rolled up his shirtsleeves and I could see the scars where he had been shocked. He said it would throw you off the stool and all would be well since the current ran from your hand down your arm to the bench never coming near your heart. He had done his bit during WW2 in a rather weird way.

[Willie B]

I had to weld down steel decking on a roof during a rainstorm. Crazy thing to be asked to do it but I was young. I put on a pair of rubber gloves then my soaking wet welding gauntlets. The water was running down my arm into the rubber gloves and I could feel that my fingers were immersed in water. No shocks and it amazes me even today thirty years after.
I took a physics course and the prof in this college was making small talk as I took extra time on my lab. He casually mentioned that he repaired radar sets in England during WW2. The procedure was to power up the radar chassis and then check voltages and troubleshoot. You did this sitting on a metal stool. The bench was all metal and grounded. He said that at all times your arms were to be resting on the edge of the bench. He then rolled up his shirtsleeves and I could see the scars where he had been shocked. He said it would throw you off the stool and all would be well since the current ran from your hand down your arm to the bench never coming near your heart. He had done his bit during WW2 in a rather weird way.

Worst shock of my life didn't involve a welder. Power was out for everyone within a mile, I got it from a neutral, (center tap on a single phase transformer) I was unable to move, virtually unable to think for 1? through 5? minutes. Voltage was likely 120?

My injuries were forearm muscle pain several days. No burns, no heart symptoms. Shock was left hand to right, my heart was right in the path.

A welder offers Open Circuit Voltage of 100 for the oldest transformer machines to 50 for the newest, safest machines. The likelihood of serious injury in a tingle from changing electrodes with a stick welder is VERY slight.

[CAVEMANN]

I got a pretty healthy shock from what was SUPPOSED to be a neutral, I don't remember exactly what I eventually found but it affected that entire part of a steel building, I also got nailed by 220 once & wished I hadn't!

[bakodiver]

I do a fair amount of underwater welding, just finished a 20 day job. I find if I am totally covered in neoprene, no skin showing anywhere, and I wear double rubber gloves, I feel essentially nothing while welding. I occasionally feel a tingle while tacking if I am holding the piece to be tacked, dog, cleat, zinc, whatever. In earlier years i was not so careful to cover all skin and got a tingle fairly often, but nothing that felt dangerous. I am very careful to never have my body between the welding cable and ground, so the shortest path is always clear of body parts. I also have the current shut off whenever I change rods or stop welding. Worst part is I can't have any metal in my mouth, ie, silver fillings, as there must be enough stray current around to dissolve them. Other than that, it is a pleasant job and pays like a busted slot machine.

[Fast Leroy]

I got a pretty healthy shock from what was SUPPOSED to be a neutral, I don't remember exactly what I eventually found but it affected that entire part of a steel building, I also got nailed by 220 once & wished I hadn't!

Neturals are current carrying conductors. The worst I've ever been shocked was by the neutral conductor on a 277 volt lighting circuit in a man basket in the ceiling of a plant. I hurt for 3 days after.

[Willie B]

Code describes neutral as grounded, some call it common. The notion it isn't live is absolutely wrong. It is supposed to be grounded, but if it isn't connected, it isn't grounded. should you become part of the neutral path you will NOT enjoy it.

[psacustomcreations]

I do a fair amount of underwater welding, just finished a 20 day job. I find if I am totally covered in neoprene, no skin showing anywhere, and I wear double rubber gloves, I feel essentially nothing while welding. I occasionally feel a tingle while tacking if I am holding the piece to be tacked, dog, cleat, zinc, whatever. In earlier years i was not so careful to cover all skin and got a tingle fairly often, but nothing that felt dangerous. I am very careful to never have my body between the welding cable and ground, so the shortest path is always clear of body parts. I also have the current shut off whenever I change rods or stop welding. Worst part is I can't have any metal in my mouth, ie, silver fillings, as there must be enough stray current around to dissolve them. Other than that, it is a pleasant job and pays like a busted slot machine.

When I was in the Army as a diver we welded and burned or cut underwater. We wore a setup similar to yours and rarely had issues. If we did, it was frequently from nicks and damages to the cables that were unnoticed.
I have metal fillings and never had issues with them but just may have been lucky.

We did have one guy lean his helmet over too close and touched the welding rod with the faceplate ring and got zapped that way.