Electric shock experiences - for those still alive

[JoeN]

Just got one a few days ago.  I left the lights on the car in my driveway and car wouldn't start.  Hooked up the battery charger which means an extension cord to the battery charger to the battery.  The two prong head on the battery charger is cracked, as I now know, right where the wire goes into it and as I was pushing it into the extension cord my right index finger, middle segment came up across it.  I was fully clothed, dry shoes with rubber soles on, but standing on ice.  Don't know if that matters with decent shoes on.  Anyway, it gave me a slightly unpleasant shock, I could feel the buzzing of the current in my finger and it stung a bit.  But nothing extraordinary.  This has happened to me many times and tends to make me think that the danger of line voltages are sort of overstated except under worst case scenarios, which can happen.  Once I got a much better shock when I was at home in my socks and a similar thing happened with a frayed wire inside of a tabletop electric grill that electrified the rim and grease catch.  But that didn't kill me either or really do any major damage, just a more severe shock.  US AC 120V RMS.

[Galaxyrise]

My first shock was when I was too young to understand what dangerous meant. I'd only just learned what "hot" actually meant thanks to an incandescent light bulb.  I stuck a finger in an outlet.  Nothing.  Then I touched the other side, and got a strong buzzing feeling.  It was much less unpleasant than the light bulb was, so I tried several times to be sure.  (How do we survive being kids?)

I started learning more about electricity over the years, and came to wonder why I got a shock in that situation at all.  I wasn't completing a circuit!  Now I've learned a lot more, but I'm still not certain, so maybe this is a good place to ask.  My guess is that my body becomes one plate of a capacitor with the other side being all of ground. That results in a tiny capacitance, thus a large impedance that ac current can flow through, allowing a few uA of current, and that's what I feel as the unpleasant buzz. 

But that doesn't explain why other kids, who choose to insert a key into an outlet, receive such a bad shock compared to what I got (still at "just" 120V.)  What am I missing?

[orbiter]

Like you guys.. I've shocked myself many times with 240v, I even did it as a child when I was picking at a cracked plug socket with a screwdriver Id found, but most of the shocks were with 30kV vehicle ignition systems,  I distinctly remember one of the ones that had me worried (it was about 15 years ago now) where i was hit with the 30kV and it went straight from one hand,  across my chest to the other hand which was resting on a suspension strut..  It left me shaking for a bit and i could definitely feel a tightness across my chest afterwards, I got checked out though and all was ok.

My grandad suffered the worst shock possible though resulting in his death ?.  He worked on the railway as a track layer years ago. One night the lights on the track laying vehicle he was operating were failing, he asked for the electricians to come out to replace lamps but there were none available until the next day.. My grandad wasn't prepared to wait until then as there was work to be done, so he attempted to get up to the lights to replace the bulbs himself,  however he was killed instantly by arcs from one of the 25kV overhead lines. We later found out that he was not really that close to the lines however it was determined that as that particular evening was very damp the electricity from the lines had jumped the moisture and that was it.

[ElectroNub]

When I was a dumb teenager, a friend and I would grab bare 120v lines and have a contest to see who could hold on the longest. I don't remember winning but I am still here today

Been shocked by more than a few spark plugs. I was rebuilding small engines at 10 years old.

I worked on 3 phase diesel generators for many years. Never screwed up once! Triple, quadruple, quintuple, checks were the norm. Safety first always!

[CatalinaWOW]

I suspect that a lot of the difference in experiences with shocks from the mains depends on the relative humidity in the area.  Dry skin is a fairly good insulator, while wet skin is not a bad conductor.  Same thinking applies to the floors or other supports involved.  When I worked for an electrical power and distribution company there was an apocryphal story about a linesman who had transferred into the area from one of the desert southwest regions of the US.  He was killed very early in his employment due to an unsafe practice that had been used hundreds of times without harm in the arid region he got his start in.

Other details matter.  The key in a socket experience I related came when our family was living in an aluminum trailer at a remote jobsite.  Lots of ground paths and every reason to expect that the wiring for this temporary camp was not the absolute best available.

[digsys]

From the beginning -
TV tube HT coils and Vehicle HT coils - so/so ... brief hurt, but not long lasting
240VAC mains - slight tingle / fuzz, sometimes I have to double check that is IS live !
Van der Graaf generators - cool
Valve amp DC rails 350-400VDC - Holly snapping FECKKK !!! I can STILL remember them (felt like blowing ALL your bones apart)!
DC - up to ~60V, no clue if it's live ... up to 80V, fuzzy > stronger fuzzy

One thing for certain - IF you panick and release adrenalin etc, you WILL cop it worse. My years playing with the Van der graaf got me
very used to NOT over-reacting to sudden jolts.
I worked with an electrician once who had to LICK his fingers and tap 415 3 PHASE to check it !! He had NO feeling if he didn't lick them.
He was a legend :-)

[EEVblog]

I've done this, it hurts:

[T3sl4co1l]

Worst (at least in principle) I've had was, I was working on a piece of industrial equipment (480VAC 3 phase), I forget how but I had touched one phase, or the DC link, maybe with a careless grip on a multimeter probe.  In and of itself not fatal, but my other arm was leaning by the front enclosure (which was off, laying on its side, as I was working inside the machine, obviously), which was grounded.  The shock wasn't really worse than any other I've had, but it's far... angrier than anything else.  The jolt was pretty intense for the loose contact I had on either surface, and the ground side (specifically, the edge of the grounded enclosure that was brushing against my inner forearm) left a small burn mark.  Nothing else I've touched has actually caused burns!

On separate occasions, I've seen the results of (fused) arc flash: the plasma ball obliterates anything in its way, leaving high velocity fragments and a sooty smudge behind.  Unfused arc flash is... something to behold at a safe distance only.


On the upside, safety procedures at that job were fairly well implemented, so there weren't any reports of injuries or worse, while I was there.  At least, that I know of.

Tim

[calexanian]

Funny this came up. I got myself with an Electro Technic Products hand held tesla coil last night. That is up to 50kv but limited current to around 1ma. Its enough to get you going though.

I have been hit many many times. 120 line voltage more than I can count. The worst one that comes to mind was about 410 volts unlimited, path hand to hand. Worst possible way to get it. Fortunately conditions were very dry or it would have been heart stopping time. That was the one that got me thinking about safety. Also I had a energized wire break from an improper stripping at a terminal and send a little dagger end of about a 12 gauge wire right at my eyeball. It looked like they used side cutters to strip a solid wire and it made that sharp stabby pointy knife edge when it breaks. Thank god I wear glasses. It bounced off my glasses lens enough for me to catch the still insulated portion. Had that hit my eye, or near it it would have stabbed me and probably would have blinded, if not killed me.  Because of that I will never give up my glasses.

[Howardlong]

Well this has been an eye opener. I am not sure whether to laugh or cry. I assumed that experiencing a shock was the exception rather than the rule, and at I was just a little clumsy with three or four "experiences".

Here does seem to be a minor correlation of us getting shocks in our younger years, although it's certainly not clear cut.

I'm no apologist for the over-cautious health and safety 100% risk averse culture, we learn better from our mistakes than we do by being talked at, but the poll results do suggest a certain degree of resignation to the innevitable.

While I am sure almost all of us don't go around looking for our next experience, in general are we too blasé about the risks, or should we all just grow a pair? Should we be doing more to protect ourselves?

[briselec]

I've been zapped many, many times.
First time I was very lucky it threw me.  I was young and had just started playing with electricity. Was on a 6 foot ladder when I grabbed a live active in one hand and the earth in the other. Next thing I know I'm sitting on my bum on the floor about 6 feet away with no idea how I got there.
Used to maintain an old high rise fire alarm system that used 240V DC. The back of the panel was covered in exposed relays that were hard to avoid brushing against while working on it. I dreaded working on that thing. DC current feels like your flesh is burning from the inside out. AC feels much nicer.
Got my hand stuck once between a live busbar and the switchboard frame. Took me a few seconds to open my hand enough to get it out.
Funny thing is what I hate more is when something unexpectedly goes bang. It always unnerves me when that happens.
 

[Kjelt]

In our safety course on work they showed us a lot of movies as this one.
A picture says more than a thousand words and don't forget that every graduated electronic engineer has a DUTY to warn everyone that is acting in an insecure/dangerous with electricity, if it is your neighbour or some newby here at the forum.

[Zucca]

This was my first one.

I was 7-6 years old. One day my AA battery powered toy just died in front of me. I went to my father bench (he is also an EE) and grab 2 banana-alligator cables, one red and one black.
Pulled out the AA battery from my toy, connected the alligator clips to the two poles and I inserted the first banana plug into the main 220VAC socket. It didn't went all the way in. Unfortunately those sockets had the children protection (smart dad, but unfortunately smart child), so I need to push at the same time the two banana connector into the socket.

All I remember was a yellow flame, my body being pushed back 1,5 meter and the house power going down. My mother showed up in milliseconds with a white face. She was shacking after realizing what I have just done.

Unfortunately the AA 1,5V battery did not recharge. FAILED.

God bless my guardian angel.

PS: After so many years in the EE, I still look back and think:"I was born to be a crazy EE".

[Howardlong]

I used to try similar things, trying to plug my 4.5v Lego motor into the mains, but at age 5 or so I couldn't figure out how to open the protective plastic covers that UK style 13A outlets have on them.

Of course a few years later I figured out how to do it with a screwdriver, and luckily knew of the potential compatibility issues of a Lego motor and AC mains.

[Stonent]

For me just the normal 120V stuff. In Jr. High our industrial engineering teacher connected a lawn mower ignition to a drill press to generate a recurring spark and successfully dared a student to let the spark go to his tongue.

Surprisingly he did two or three sparks and didn't jerk back.

The dare was that the teacher would give him $80 for doing it. The $80 was in the form of a writing pen filled with shredded $20 bills from a visit to to the facility that prints them.

[n45048]

I have to say, the Aussie AC mains socket seems to be the more clever of designs; Thin blades where only the smallest of objects would fit and actually contact the terminals. No need for fancy shutters or the like. No round holes or large openings.

Although I do like the Neutrik PowerCON plugs and sockets.

In any case, for some reason, this thread reminds me of this classic Mr. Bean episode (particularly at 2:40 to 3:35)

[Rerouter]

Because i clearly fail at learning my lesson...

atleast 8 times on full mains, (265V at my place due to all the solar)
most memorable was a hand held mixer that had been thrown in the sink to clean while still being plugged. I put my hands back in the water a number of times trying to make sense what in the water could make the tingling feeling, until i traced the cord coming out of the water...

a few kicks at 415V, that drives its lesson home, testing the trigger on a welder, while still leaning on the welder with my elbow, a few expletives but no marks or burns,

next up the rank,  a few KV off a car ignition coil, that is a feeling i wont soon forget, it holds you far worse than mains can dish out, and even makes it very hard to move your face to say call out help, still no burns,

and finally, a non discharged CRT, i was poking around a bit of test equiptment looking for another error when my ear touched the step up transformer which was missing some insulation at the pin, it left a small singed area, and resulted in me wearing a 15KG bit of test equipment as a stunning hat until my flailing brought it back to the floor with me still wearing it, the hat did not survive the ordeal,

[tom66]

It's certainly true that you need to protect yourself. Mains isolation via transformer is a must, for example. I had a friend who took 120V from a PSU without too much adverse effect because it was properly isolated. Still kinda rubbish that the heatsinks were live though, and most modern PSUs try to avoid that. This one was from the early 90s.

Almost every power supply I have repaired has live heatsinks. Having heatsinks that are not live is the exception rather than the rule. Usually, they are tied to the -ve of the bridge rectifier/bulk cap, which means they float up to 120V  from mains.

[klr5205]

In order of my surprise:

Motorcycle spark plug across the chest. (In the left hand, out the right leg to the exhaust)

Before I knew much better - but still enough to be dangerous- I got a zap from directly touching the electrode at the top of my solid state tesla coil. Touching the streamers is rarely more than a tingle, but in that case you have the benefit of the voltage drop across the air gap between the secondary and your finger. (I thought it wasn't oscillating, but in reality it just wasn't working well enough for sparks to break out on their own. The top of that coil was very much at high voltage! Fun fact: The problem was two too many turns on my gate drive transformer.)

Prying a wall-wart off a plug strip, I once managed to get my finger stuck between the live prongs before they were disconnected. I felt dumb.

Approximately 200VDC from a non-isolated heatsink. Rubber soles on a wooden floor meant this was more of an audio/visual thing than anything else. Barely felt a thing.

[Seekonk]

My worst was a crazy wired building that I was helping demolish office into warehouse space.   I was up ten feet on a ladder taking apart a junction box, left hand grabbing onto conduit and right hand on 277V.  Power ran from breakers left side to right  AND Power ran from breakers right side to left.   I had disconnected all the wires on the left side before moving to the junction box.   Seldom do you get as good a path through both arms.   After that I got one of those non contact test lights.

30 years ago there was a good article on electric shock.  Haven't seen as good a one since.  It said you can die 25 years later from an electric shock.  You are not out of the woods yet!

[amyk]

Have had onlly one or two close encounters with the mains (wasn't extremely painful - I have very dry skin - but still an unpleasant numbing sensation), but then again, I usually work on low-voltage circuitry.

My most memorable and painful shock came from a treadmill that turned into a crude approximation of a Van de Graaff generator because of a failed discharge strip...

[KJDS]

While I am sure almost all of us don't go around looking for our next experience, in general are we too blasé about the risks, or should we all just grow a pair? Should we be doing more to protect ourselves?

I used to free solo rock climb, which is almost as risky a hobby as it gets.

I also used to drink in the Luton branch of the Glasgow Rangers supporters club, which was far more risky on a Friday night.

[max666]

Never had one, never will, I think I know what I'm doing    1 (0.8%)

Oh look there is the first one, I've been waiting to see how long it took 

[Ericho]

In the 80's I got zapped ones while I was trouble shooting a relay cabinet of a Ward Leonard driven winch.

Someone decided to ignore the big sign I left at the controlls (DO NOT OPERATE)

550V dc from my left hand to my right upper arm, Nocked me out and another hour of blury vision after I woke up. A few hours of sleep and I was fine.


I suppose that was a close one.

[Ericho]

Never had one, never will, I think I know what I'm doing    1 (0.8%)

Oh dear,,,