Electrical Safety

Discussion in 'Homework Help' started by jkele, Dec 22, 2010.

  1. jkele

    Thread Starter New Member

    Oct 17, 2010
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    Need to get some concepts right, If i was to grab a 20,000 V wire and be grounded i create an electrical path and hurt myself. However if ground is defined to be at 0V then isnt connecting a 20 000V to 0V the same as connecting a voltage source to a short circuit?
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
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    No, the act of connecting the 20KV voltage source is what makes the short circuit. The better expression is "shorting the voltage source to ground".

    BTW: If you are still in the current path, you still get shocked. Ground can't protect you in that situation.
     
    Last edited: Dec 23, 2010
  3. Georacer

    Moderator

    Nov 25, 2009
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    1,266
    You will even get hurt if you touch the two ends of a 20000 Volt source, without stepping on the ground. The voltage will stop your heart which is in the shortest path of the current (from one hand to the other) and the current will fry your cells.
     
  4. jkele

    Thread Starter New Member

    Oct 17, 2010
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    0
    Thanks for that answer.. but sorry i am still a little confused.

    So what you are saying is if a 20KV wire is connected to ground via a copper wire - this is shorting to the ground. However if i take myself and act as a wire between the 20KV wire and ground this is not shorting to ground? (lets assume that i act as an ideal wire)
     
  5. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    As an "ideal wire", yes, you are "shorting" the 20KV to ground. But, you are not an ideal wire, you are a carbon resistor, and therefore limit the current...a little. ;)

    Ken
     
  6. retched

    AAC Fanatic!

    Dec 5, 2009
    5,201
    312
    A wire floating in the air is 0v but not ground.

    If you connect a wire that is connected to a 20kv source to that floating wire (0v) it is not the same as connecting it to ground (Which is often at 0v)

    So in a 20kv battery, attaching a wire to the + terminal and rubbing it all over your body is not "shorting to -" or "shorting to ground"

    If you take the same wire and touch it to the dirt, you are also not shorting it to ground. The dirt is at 0v, but offers no return path to the battery, therefore not completing the circuit.

    Current is like ants that will only march if they can get back home.
     
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