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Elctrical shock?

  1. May 2, 2010 #1
    elctrical shock??

    It is said that, when working with electricity we should wear shoes for safety from electrical shock....


    Lets say I am wearing shoes and by mistake i put my finger in a 230 V a.c. socket ,,,,, will I be feeling any electrical shock or not.....
     
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  3. May 2, 2010 #2

    berkeman

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    Re: elctrical shock??

    Well, first of all, please do not stick your finger into an electrical outlet. Not that I have personal experience with that sort of thing, but whatever.

    The AC Mains power supplied to your electrical socket is mainly differerential (between Hot and Neutral, the two long slots in power outlets in the US), but the Hot lead presents most of its voltage with respect to Earth ground (again in the US). So if you touch the Hot lead in an AC Mains socket for example, and have another hand or foot touching Earth ground, you will be a resistor for an unpleasant current. You should not rely on shoes alone to help you avoid electrical shocks. You should try to obtain some training in electrical safety. Is such training available to you?
     
  4. May 2, 2010 #3

    sophiecentaur

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    Re: elctrical shock??

    A much better practice than wearing rubber boots (a thick carpet or even a laminate floor if usually fairly good insulation, in any case) is to keep one hand in your pocket when fiddling inside live equipment. It avoids the thumping shock you can get when you are holding the case with one hand an grab hold of a live component. Current passing across your chest is a lot worse than a path across one hand.
    Another tip is to use the back of your hand rather than the front, when 'exploring'. If your hand gets a belt, the muscles tighten up and the fingers naturally curl away from the live part., breaking the circuit.
    Better still - stay clear until you really know what you're doing!
     
  5. May 3, 2010 #4
    Re: elctrical shock??



    thx, but still my question is unanswered

    i want to ask that if i m wearing shoes and not touching anything with my hand,,,

    WHY would I get electric shock.....
     
  6. May 3, 2010 #5
    Re: elctrical shock??

    Providing that you do not give a path to neutral or ground no you will not get a shock.
    There is a story (probably apocryphal) of a JCB (back hoe) driver who got his bucket stuck in an overhead power line, while sitting in the machine (sitting on 4 big rubber tyres) he was OK, he then worked out that if he jumped clear he would be OK, his problems started when, as he said "turned round and shut the door of the cab".
    Do you know that you don't have another path to ground? Don't try it.
     
  7. May 3, 2010 #6

    sophiecentaur

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    to get a shock, some current has to flow THROUGH you. If you are just standing there - with or without rubber boots- where would the current flow from/to? You'd have to be touching something 'live'.
     
  8. May 3, 2010 #7
    Re: elctrical shock??

    I'm not sure that I can put this in a simpler form but I'll try.
    In order to get an electric shock from "normal" sorts of voltage i.e a domestic socket you need to provide a path through the body to neutral or ground.
    Case 1 standing with bare feet, and not touching anything else, touch a live wire, result shock.
    Case 2 standing with insulating shoes on, and not touching anything else, touch a live wire, result no shock, (probably but anyone who tries this for real is putting themselves in line for a Darwin award).
    Case 3 standing with insulating shoes on, touching something else, touch a live wire, result shock.
    From your question and responses to answers it is obvious that you have little knowledge of electricity, please please do not try touching live wires as an experiment.
     
  9. May 3, 2010 #8
    Re: elctrical shock??

    Case 2 standing with insulating shoes on, and not touching anything else, touch a live wire, result no shock, (probably but anyone who tries this for real is putting themselves in line for a Darwin award).
    How can you say that ,I have got very little knowledge,,,, if you have got guts then perform this case too and see the result.....
     
    Last edited by a moderator: May 3, 2010
  10. May 3, 2010 #9
    Re: elctrical shock??

    Where can I pick up my award?

    When I was a kid we had a table lamp with a metal pull chain switch. I noticed that sometimes when I pulled the chain to turn it on that it would give me a very mild shock. It was usually very mild and felt more like a tingle than a shock. And sometimes I could pull the chain and I would feel nothing at all. Well, eventually we moved the lamp to the basement of our home. Our basement had a concrete floor. Being a kid and being it was summer time I would sometimes go barefoot. It just so happened that the first time I tried to turn on the lamp after it was moved to the basement that I was standing barefoot on the concrete floor. When I pulled the chain I received the worst shock of my life. I felt the current going through my arm, through my chest, and through my leg. I remember seeing the chain laying across my hand but I could not do anything about it. My movement and whatever I was looking at was involuntary. Next I remember seeing the ceiling and it was spinning around. Next I found myself laying on the floor dazed and unable to think clearly. My mom came to the door and asked if I was okay. I must have let out a yell, but I don't remember that. I tried to answer her but I could not get any words to come out. It took several minutes for me to get myself back to normal.
     
  11. May 3, 2010 #10

    mgb_phys

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    Re: elctrical shock??

    You were lucky!
    The danger is that the risk depends on a lot of factors which change.

    120v or 230V obviosuly makes a big difference.

    How long you are in contact with the live wire, a momentary (1/100sec) brush is just a tingle, if your hand contracts onto the live wire and you are shocked for more than a few seconds = much more dangerous.

    The total resistance of the path to ground, how sweaty your fingers and feet are.

    The exact path through your body, how much went over your skin compared to through your muscles. And especially which hand you used, a shock from your right hand to ground is safer than the left hand, which is still safer than a shock across both hands (think where you heart is)

    An AC current of 15mA across your heart can be enough to kill you, >50Ma for more than a couple of seconds is generally bad.
     
  12. May 3, 2010 #11

    uart

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    Re: elctrical shock??

    That was not the question you asked. You asked about wearing shoes and accidently putting your finger into a 230V ac socket. (Ok re-reading the other posts I guess you meant that you're not touching anything with the other hand, right).

    Here are the really important facts.

    1. It depends on whether you touch just one wire or both. If you just touch one wire and you're not touching anything else and either your shoes or your floor material are very good insulators then no you wont get a shock. But be careful because it's very easy to accidentally be touching something else that is not so well insulated, either through another limb or part of your body.

    2. Given the same scenario as 1 above, but if your one hand touches both wires (either active and neutral or active and ground) at the same time then you do get a nasty shock that may give you some painful burns on your fingers but typically wont kill you. This is because the current circulates though just the one hand and hence will not travel through your vital organs, in particular the heart. This situation is nasty at 230 volts AC but gets a whole lot worse at higher voltages, don't try it.

    3. If you were to touch one wire with each hand then you're now in a much worse situation and could easily die. Here the current flow through the body which can cause the heart to stop (it doesn't actually stop so much as go into spasms, but either way it stops pumping blood and you die!). The same thing can happen if the current flows from the hand to the feet or anywhere else in the body (other than the same arm that's touching the live one), you can get current through your heart and may die.

    I hope that helps.
     
  13. May 3, 2010 #12
    Re: elctrical shock??

    I was also lucky in that I am right handed. If I had grabbed that chain with my left hand it could have been worse.

    You're right, there are a lot of variables involved. My work and hobbies have put me in close proximity to high voltages for most of my life. I've been shocked from sources ranging from 90 volts to 25000 volts. But the worst of them all was that little lamp with the metal chain switch.
     
  14. May 3, 2010 #13
    Re: elctrical shock??

    Turtle Miester I’m afraid that you don’t qualify on two points, the award is posthumous and the events leading up to death must show a certain level of idiocy, namannitant on the other hand, if he goes ahead and plays with live wires, looks like a good candidate. (http://www.darwinawards.com/).
     
  15. May 3, 2010 #14
    Re: elctrical shock??

    Oh well. I came close. Maybe next time. Yes, I still play with live wires. :)
     
  16. May 4, 2010 #15
    Re: elctrical shock??


    Thx that was really good answer,, and it will help me a lot.....
     
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