Electricity on the Human Body?

Discussion in 'General Electronics Chat' started by therock003, Jul 17, 2011.

  1. therock003

    Thread Starter Member

    Jun 25, 2008
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    What does it mean for the human body to carry out electricity? How much does it carry, and what quantities are lethal?

    Also why is it sometimes that you touch someone and you get a slight shock.

    And most importantly, when i shower, i sometimes feel like i get small zaps form the water handle that carries out the water, since its metal. Why is that?
     
  2. debjit625

    Well-Known Member

    Apr 17, 2010
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    MOST IMPORTANT
    Call an electrician,and check your house wiring for any leaks and also make him check that house earthing(grounding) is ok.
     
  3. RRITESH KAKKAR

    Senior Member

    Jun 29, 2010
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    For human body AC/DC shock start topically at 48V, it also depend on skin.
     
  4. tom66

    Senior Member

    May 9, 2009
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    1mA can be felt, 10mA is painful, 100mA kills.

    I've heard as low as 40mA can cause fibrillation of the heart. For comparison, 40mA could light two small LEDs.
     
  5. debjit625

    Well-Known Member

    Apr 17, 2010
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    http://en.wikipedia.org/wiki/Electric_shock

    You mean by touching some hot chick yes..yes..yes I know that one
     
  6. Adjuster

    Well-Known Member

    Dec 26, 2010
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    If you are really experiencing electric shocks while showering, you or others may be in danger of death or serious injury.

    Do not use the shower again until the electrical installation at your home has been checked over by a competent electrician.


    A shower is a very dangerous location for electric shock, as bare wet skin is likely to make low-resistance contacts. Any pipework which became electrically live could be lethal. Only a relatively small voltage - perhaps tens of volts - might be necessary to circulate enough current to be dangerous ( about 10mA upwards).

    Static charges picked up on the body while walking around are quite another matter. A large voltage may be achieved, many thousands of volts would be quite typical, but the energy available is limited to what is stored by your body capacitance. It is usually impossible for enough current for long enough to seriously harm the body to result from discharging this sort of static. (Perhaps someone with an artificial heart pacemaker might be in some danger?)

    Static discharges can of course wreck electronic equipment. They can also result in a serious fire or explosion hazard in the presence of inflammable gases (e.g. cooking gas, petrol (gasoline) vapour) or dust (flour, coal dust etc.)
     
  7. monster_catfish

    Active Member

    Mar 17, 2011
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    It does sound as though live wires running through the conduit pipes in the poster's home are shorting out, which is a VERY big deal and grievous danger, as pointed out by Adjuster.

    I had that happen in my home, and it came to my attention when the concrete upstairs floor started to heat up, on account of the massive current leakage from old wires. I got that sorted real fast, since any water spillage on that floor would have crispy-fried anyone who stepped into it.
     
  8. debjit625

    Well-Known Member

    Apr 17, 2010
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    The most important thing,it will be horrible sean to be dead while in shower naked.
     
    #12 likes this.
  9. gootee

    Senior Member

    Apr 24, 2007
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    Yes, get your wiring checked, "NOW".

    As far as general lethality goes, a very large current obviously can kill you. A fairly large current, which doesn't immediately vaporize or boil important parts of you, but makes you unable to let go of its conductor for example, clamps your heart muscle, stopping your heart. BUT, in the case where your heart muscle is clamped, being freed from the electricity will usually result in your heart automatically restarting, by itself.

    More dangerous are the low currents, 100 to 200 mA or even less, which often cause your heart to fibrillate. In that case, even if your body is freed from the electricity, your heart usually will NOT automatically restart itself, and you will die anyway, unless there is a defibrillator handy.
     
  10. praondevou

    AAC Fanatic!

    Jul 9, 2011
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    Perception changes depending on frequency of the current.
    How much current will flow depends on the body resistance, which in turn depends on the location of current flow and the resistance of the skin at the point of contact.http://pchem.scs.uiuc.edu/pchemlab/electric.htm

    [​IMG]

    [​IMG]
     
  11. John P

    AAC Fanatic!

    Oct 14, 2008
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    Don't people just luuuuurve giving dire warnings about dangerous conditions that someone else needs to look out for!

    The problem with the shower is most likely a buildup of static charge, annoying but harmless. But you can make a quick test: do you get the zap when you first get into the shower with no water running, or only after the water has been flowing for a while? In the first condition, there's been no chance for static buildup and I'd expect no zap to occur (unless you shuffled over a dry rug on the way to the bathroom--don't do that) but if there's a static buildup, you'd feel it once you'd been under the shower a while. I imagine that the materials that the tub and pipes are made of would have a large effect on this--if it's all plastic, you'd be at most risk, but metal pipes and a cast-iron tub would carry any charge away before you noticed it.

    Of course if there really is an electrical connection to the pipes, that's serious business. Never say never, but I doubt it.
     
  12. monster_catfish

    Active Member

    Mar 17, 2011
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    I would imagine that any warning which saves a life was worthwhile mentioning, even if the person giving the warning took pleasure in doing so, which I would find odd and unexpected.
     
  13. gootee

    Senior Member

    Apr 24, 2007
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    And remember, electric current doesn't follow the path of least resistance. It follows ALL paths, in inverse proportion to their resistances.
     
  14. Wendy

    Moderator

    Mar 24, 2008
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    Hmmm, somehow I don't think I would care.

    Reminds me of another discussion, where they had a heater with exposed wiring in the shower head. No joke! That thread was quite long. The gist was, don't do it, even if it could be made safely (and this most definitely wasn't). I would do a careful inspection to make sure some genius didn't install something like this on yours.
     
  15. gootee

    Senior Member

    Apr 24, 2007
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    To assess a risk one needs both the probability AND the cost of occurrence.

    What would be the mechanism for building up a static charge after one was in the shower for a while? And where would it build up; on what? That seems like the last situation in which one would expect static charges. Does water running through plastic pipes build up a charge on the end of the outside of the pipe? The charge can't migrate along a plastic pipe, since it's not a conductor. So only the charge induced very near to the end of the pipe could affect the person. And any metal fixtures (or metal pipes) that were in contact with the water (as i think they all would be) would have their charge removed, through the water in the pipes. And I believe that the same would hold for the person's wet body and all wet surfaces in the shower. Maybe the OP has plastic fixtures that stay dry?

    If it's not static, and especially if he has plastic pipes, then maybe he also needs to worry about something like an electric water heater or water pump electrifying the water itself, which might not be as obvious after the shower is running for awhile and the water carries most of the current down the drain (the current that isn't going out through the supply lines or into other ground-return paths, which would probably usually be the bulk of it).

    Yes, it is all very, very improbable. But to assess a risk one needs both the probability AND the cost of occurrence. A very low probability coupled with a very high cost of occurrence can still indicate a significant risk, i.e. worth worrying about.
     
    Last edited: Jul 18, 2011
  16. praondevou

    AAC Fanatic!

    Jul 9, 2011
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    quite common in Brazil. they use shower heads at 220VAC or 120VAC, more often than not the earth wire is not connected, because there is nothing you could connect it to. So just two wires, contact is being made by simply twisting the wires (for up to 30A). It made my hair stand on end when I saw this....
     
  17. steveb

    Senior Member

    Jul 3, 2008
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    "Most importantly" indeed! Quite possibly the "why" is that you have a major electrical wire flaw/fault that could result in electrocution or a fire.

    More than one person has been killed in the shower due to a wiring malfunction or an error in installation.

    Don't take a chance. Have an electrician check it out for you. If you don't get an answer about the cause and a real cure, then find someone else until you get an answer.
     
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