# Accidental Electrocution **URL:** \ **Category:** Factual Questions\ **Created:** [January 17, 2017, 10:30am UTC](https://boards.straightdope.com/t/accidental-electrocution/777379 "2017-01-17T10:30:00Z")\ **Posts on this page:** 10\ **Page:** 2
**Author:** ![watchwolf49](https://avatars.discourse-cdn.com/v4/letter/w/e9c0ed/32.png) [@watchwolf49](https://boards.straightdope.com/u/watchwolf49)\ **Post date:** [January 18, 2017, 1:32am UTC](https://boards.straightdope.com/t/accidental-electrocution/777379/21 "2017-01-18T01:32:29Z")
I’ve been hit with 500 VAC … took a couple hours to move my arm again … but I lived … ---
**Author:** ![Flyer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/flyer/32/7298_2.png) [@Flyer](https://boards.straightdope.com/u/Flyer)\ **Post date:** [January 18, 2017, 1:43am UTC](https://boards.straightdope.com/t/accidental-electrocution/777379/22 "2017-01-18T01:43:44Z")
> [@bob\_2](#): > > I think that in most cases of accidental electrocution, the victim was doing something foolish or downright stupid, like poking a screwdriver in to see what happens. As a matter of fact, I recently learned about such a case. The guy wanted an electric fence around his garden to keep out the neighborhood dogs. But instead of setting it up properly, he connected it directly to his home’s electrical system. As things turned out, he was the fence’s first victim. ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [January 18, 2017, 2:32am UTC](https://boards.straightdope.com/t/accidental-electrocution/777379/23 "2017-01-18T02:32:48Z")
> [@Renee](#): > > How badly do you have to get electrocuted for it to really injure you, assuming you don’t have a pacemaker or something? (the minor nitpick that electrocution is not shock has already been mentioned) Anyway, electricity tends to kill you in one of two ways. The first way is that it screws up your heartbeat. It takes a surprisingly small amount of current to throw your heartbeat out of whack. The “safe” level of current as used by many safety standards is 5 mA, or 0.005 amps. To put that into perspective, your typical wall outlet is capable of sourcing 15 amps, or 15,000 mA (milliamps). This tiny 5 mA level of current can throw your heart into fibrillation. In that state, your heart isn’t really pumping blood. It has its rhythm all screwed up and it just kinda shakes chaotically. Your heart has kind of a funny design in that this fibrillation state is actually stable, meaning that the heart will happily stay in fibrillation unless something forces it out of that state, like someone whacks your heart with a portable defibrillator. Without a defibrillator, you’ll generally pass out fairly quickly and die not too long after that. A friend of mine (who sadly is no longer with us) helped design equipment for a doctor who was doing research into early pacemakers way back when, and they found out through animal studies that the frequencies we tend to use for power, around 50 to 60 Hz depending on what part of the world you live in, are about the best possible frequencies for throwing your heart into fibrillation. So from a safety standpoint, we really couldn’t have picked worse frequencies to use. While currents above 5 mA can kill you, the probability of death is rather low. A lot depends on exactly when the shock is applied, since your heart is more sensitive to having its rhythm disrupted at certain parts of its cycle than at others. Generally speaking though, as the current level increases, so does the risk of fibrillation and death. By the time you get up to around 100 mA (0.1 amps), the danger of death is fairly significant. Even so it’s still a bit hit or miss. The funny thing is, after you reach a certain level of current, the risk of death actually starts to drop. The reason for this is that at higher current levels, instead of going into fibrillation, the heart muscles tend to just clamp. Now at this point the heart isn’t pumping blood, so if the source of current isn’t removed pretty quickly you’re still in a world of hurt. But, generally speaking, if the current source is removed, the heart will go back into a normal rhythm afterwards more often than not. As the current continues to increase beyond that point though, the risk of death once again increases. Now you’re getting into the second way that electricity kills you. It literally cooks you to death. Electricity going through the body generates heat, and it can literally cook your body to death. This method of death is a lot less hit or miss. This is how the electric chair kills you, and that tends to have a fairly low survival rate. This is also how lightning kills you, though lightning is so high in voltage that it behaves very strangely and unpredictably. To put things in perspective, your typical lightning bolt is somewhere around a billion volts and has a current of a couple hundred thousand amps. The electric chair, which tends to kill pretty reliably, is only a couple of thousand volts. The path that the current takes through your body is important. Touch your fingers to slightly exposed prongs on an electrical plug and the current goes from finger to finger through your hand. The current doesn’t go through your chest, so no risk of fibrillation. On the other hand, touch an improperly grounded light switch with one hand while touching a metal sink with the other, and the current goes from one hand to the other, through your chest, and now you do have a risk of fibrillation and death. Moving on to circuit breakers and such, a circuit breaker isn’t designed to stop you from getting killed. It’s designed to stop there from being a fire when the wires get overloaded or to shut power off if there’s a major short. The typical breaker for an outlet won’t trip until the current reaches more than 15 amps. You can easily die from a lot less current than that. Over 15 amps of current and the wires can overheat and catch the walls on fire. That’s why you have breakers. A ground fault circuit interrupter (GFCI) measures the current going through the hot wire and the neutral. If they aren’t equal, it assumes that the current found another way to get back to ground, which is often through a human body, and it shuts the circuit off. The primary purpose of a GFCI is to save human lives when there’s a ground fault. An arc fault circuit interrupter (AFCI) looks for arcing on the circuit. If it detects arcing, it shuts the circuit off. This is primarily designed to stop frayed extension cords from burning down your house. GFCIs started becoming required by law in the 1970s. AFCIs started becoming required in the 1990s. There’s no requirement to retrofit them into older homes. Installing them is generally as easy as replacing a breaker or an outlet though. It’s not difficult if you have some knowledge of electrical wiring. ---
**Author:** ![OldOlds](https://avatars.discourse-cdn.com/v4/letter/o/a3d4f5/32.png) [@OldOlds](https://boards.straightdope.com/u/OldOlds)\ **Post date:** [January 18, 2017, 2:45am UTC](https://boards.straightdope.com/t/accidental-electrocution/777379/24 "2017-01-18T02:45:42Z")
> [@Flyer](#): > > As a matter of fact, I recently learned about such a case. The guy wanted an electric fence around his garden to keep out the neighborhood dogs. > > But instead of setting it up properly, he connected it directly to his home’s electrical system. As things turned out, he was the fence’s first victim. About 35 years ago, when (it seems) there was a lot more crime of the B&E sort, a it was common in the 1 bedroom and studios around Fenway (Boston) to have a cast iron radiator in front of the only man-sized window. There were lots of stories circulating about people cutting an appliance plug and fastening one side to the radiator, and the other to a metal object or the window frame itself. The idea was that a person climbing in the window would complete the circuit. I never saw this with my own eyes and I have no idea if it was actually done to any significant degree, but your story made me think of it. And yes, I recognize what a horrible idea it was- I lived in the suburbs where we just had house alarms that 1. never stopped a criminal and 2. liked to go off for no reason at 5am on a Saturday ---
**Author:** ![Renee](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/renee/32/287_2.png) [@Renee](https://boards.straightdope.com/u/Renee)\ **Post date:** [January 18, 2017, 3:08am UTC](https://boards.straightdope.com/t/accidental-electrocution/777379/25 "2017-01-18T03:08:06Z")
Thank you for the detailed reply. Are there any stats on how often a person does die from an electrical shock in the home? Just curious. > [@engineer\_comp\_geek](#): > > The path that the current takes through your body is important. Touch your fingers to slightly exposed prongs on an electrical plug and the current goes from finger to finger through your hand. The current doesn’t go through your chest, so no risk of fibrillation. On the other hand, touch an improperly grounded light switch with one hand while touching a metal sink with the other, and the current goes from one hand to the other, through your chest, and now you do have a risk of fibrillation and death. Once, I touched an electric fence with both hands (don’t ask.) THAT hurt like a mofo. I kinda thought I might die, even though the zap was brief. Not recommended. ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [January 18, 2017, 3:10am UTC](https://boards.straightdope.com/t/accidental-electrocution/777379/26 "2017-01-18T03:10:07Z")
> [@Renee](#): > > Thank you for the detailed reply. Are there any stats on how often a person does die from an electrical shock in the home? Well, once, at most, I would imagine. > [@](#): > > Once, I touched an electric fence with both hands (don’t ask.) THAT hurt like a mofo. I kinda thought I might die, even though the zap was brief. Not recommended. Well, as long as you could just walk away, **Renee** , that fence isn’t gonna bother you no more. ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [January 18, 2017, 3:31am UTC](https://boards.straightdope.com/t/accidental-electrocution/777379/27 "2017-01-18T03:31:32Z")
> [@engineer\_comp\_geek](#): > > The path that the current takes through your body is important. Touch your fingers to slightly exposed prongs on an electrical plug and the current goes from finger to finger through your hand. The current doesn’t go through your chest, so no risk of fibrillation. On the other hand, touch an improperly grounded light switch with one hand while touching a metal sink with the other, and the current goes from one hand to the other, through your chest, and now you do have a risk of fibrillation and death. An old plumbers trick (while wiring things like disposals) is to keep one hand in your pocket or behind your back. This keeps them from bracing themself (since they’re usually leaving into the sink bay) against any of the copper piping with their other hand. That way, if they do grab a hot wire, it goes in and back out of their finger or, hopefully, in their hand and back out somewhere on the same side of their body. Holding a copper supply/drain pipe with their other hand makes greatly increases the chances that the the current will travel through their chest. But, as I said it’s an ‘old’ plumber’s trick. I can understand not shutting off the power, but neon testers are like $5 dollars. Hell, I think I have three of them (in addition to an good DMM). But I understand the concept. ETA, while we’re here, always make sure to not just check hot to ground, but also neutral to ground. I mean, things get wired incorrectly, but a shared neutral is never a fun surprise. Especially a really messed up shared neutral that’s actually 240v on the hot side that you think is off (never had that happen, but I have run into a shared neutral, also been bitten by a dimmer that wasn’t all the way in the off position). Always test what you’re working on. Hot to ground (and hot to neutral, while you’re there), neutral to ground and ground to the box if the ground and the box aren’t bonded. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [January 18, 2017, 4:29am UTC](https://boards.straightdope.com/t/accidental-electrocution/777379/28 "2017-01-18T04:29:20Z")
To further what **engineer\_comp\_geek** said, people sometimes say things like “It’s not the volts that kill you; it’s the amps”. But really, it’s neither: What kills you is either the hertz or the watts. And while a GFCI is never a bad idea (though it’s mostly useful where there’s an outlet close to water), AFCIs are not suitable for all outlets, because a lot of things (including most things with motors) will trip them even when operating correctly. ---
**Author:** ![48Willys](https://avatars.discourse-cdn.com/v4/letter/4/db5fbb/32.png) [@48Willys](https://boards.straightdope.com/u/48Willys)\ **Post date:** [January 18, 2017, 9:01am UTC](https://boards.straightdope.com/t/accidental-electrocution/777379/29 "2017-01-18T09:01:43Z")
> [@Joey\_P](#): > > Exposed conductor on power cord. Device keeps working, but it’s very easy to grab and receive a shock. This is very common (almost too common) on vacuum cleaner cords since they get run over from time to time, and even though the hot conductor can become exposed it doesn’t create a short that trips the breaker to let the user know that there’s a problem. Further more, most people, while using a vacuum, are holding the power cord, specifically to avoid running over it which makes them that more more prone to getting a shock a shock. > > To add to that, IIRC, my vacuum may have\*\* even said to replace the entire vacuum when that happens. Many people don’t know enough about electricity to A)identify the shiny copper as a threat B)If they do, know that some electrical tape can do a good job of making the problem much safer and C)have any interest in replacing a perfectly good vacuum because the cord is frayed, to the point that they’re almost going to use it in spite of that just to give a middle finger to the manual. \*\* It would be nice if the cord was plugged into the vacuum end as well, \*_not only so the user could replace it every few years, but also so when they tried to get that just a few more feet it would unplug itself instead of bending the prongs and creating a dangerous situation at that end as well._ > > Perhaps, and I’ve never given this idea any thought whatsoever until just this second, the cord could shielded in some kind of grounded foil. That way if the user runs over it enough times that they wear through the outer insulation, the shield and the conductor insulation, it shorts itself out and that’s the end of that, the cord is garbage. No more using it, but no one gets a shock either. > _Speaking of plugs/outlets_ the way they’re set up in the US (vs the UK), the prongs are energized before they’re fully inserted and I KNOW I’m not the only person that’s used my hand to find the outlet in a place I can’t see and then slid the plug down my finger and been bitten. You only make that mistake once, well twice. > > \*\*To be fair, I’m going from memory on this, but looking at the bissell website, the power cord is listed as a ‘service center part’, not something they’ll send out. I’m sure that’s just be it’s hardwired, but if they gave it a molded end and had it plugged in, ISTM that would solve a few things. > > (disclaimer: please excuse any typos or misinformation, it’s early and i’m still tired) Bolding mine. My grandma’s old upright Hoover used to be that way. It was basically a long two pronged extension cord. I used it as such fairly often. They could be purchased from Hoover at that time. I think that I replaced hers about once every three years or so, due to wear. They did have a tendency to unplug themselves as you suggested. I’ll guess that Hoover saved pennies by discontinuing this feature. ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [January 18, 2017, 10:43am UTC](https://boards.straightdope.com/t/accidental-electrocution/777379/30 "2017-01-18T10:43:15Z")
> [@Renee](#): > > Thank you for the detailed reply. Are there any stats on how often a person does die from an electrical shock in the home? Just curious. About 50 or 60 people die in their home from electrical shock per year. About 400 people die per year from electric shock while working. There are about 400,000 house fires per year, resulting in about 2,500 deaths. Of those, about 50,000 are caused by electrical faults, resulting in about 500 deaths. Arc faults are by far the leading cause of these fires. [Previous page](https://boards.straightdope.com/t/accidental-electrocution/777379.md?page=1)