Nichrome / FeCrAl heating element

Discussion in 'General Electronics Chat' started by ilogix, Jan 20, 2016.

  1. ilogix

    Thread Starter New Member

    Jan 20, 2016
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    If I touch a Nichrome or FeCrAl heating element, with bare hands, and bare feet will I get electric shock?
     
  2. Robin Mitchell

    Well-Known Member

    Oct 25, 2009
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    Depends on the set-up.

    If the wire is connected to the mains and the earth that you stand on is at the same potential as the netural wire in the mains then most likely yes, you will be shocked.
    If your power supply is from a battery (more specifically mains independent AND does not have an earth connection), then no but always practice caution and always disconnect the supply before working on it!
     
  3. ilogix

    Thread Starter New Member

    Jan 20, 2016
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    Thanks.
     
  4. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    And don't forget about the burning flesh aspect of touching heating wire..
     
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  5. ilogix

    Thread Starter New Member

    Jan 20, 2016
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    Thanks, the question was more theoretical :)!

    As in, will the electric current prefer the path through the Heating Element wire, or will it flow through the Human body.

    Technically, I think it is a question of the value of Resistance offered by the Heating Element wire (function of length, cross section, material i.e., resistivity) vis-a-vis that of human body.
     
  6. Robin Mitchell

    Well-Known Member

    Oct 25, 2009
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    That is a common error that people make.
    "It has less resistance so it will all go through the wire".

    That is NOT true. The current will always take every path that is available. The size of that current is a function of the supply voltage and the resistance of every path. That is why if there is an appliance such as a light bulb in the house, even when it is turned on you will still get shocked if you touch the line conductor going to the light.

    The size of the current that will enter you is a function of your resistance, the voltage of the supply and the internal resistance of that supply. The reason why some supplies have a max current is because of the internal resistance. For example, a battery may have an internal resistance of 1 ohm and a voltage of 5V which would result in the maximum current of 5 / 1 = 5A.
     
  7. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    Have you read the great articles this site also offers..
    http://www.allaboutcircuits.com/textbook/direct-current/chpt-3/importance-electrical-safety/
    Specifically this..
    http://www.allaboutcircuits.com/textbook/direct-current/chpt-3/shock-current-path/
     
  8. ilogix

    Thread Starter New Member

    Jan 20, 2016
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    Point well taken! As long as I will be providing an alternate path for the current to flow to ground, some current will flow proportional to the voltage and body resistance, even if the competing parallel path might be a low-resistance path.
     
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