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Ground and neutral

  1. Jun 24, 2010 #1
    hello friends

    can i say that Ground(earth) and neutral are same ?
    if not so, please distinguish them for me :smile:


    thanks
     
  2. jcsd
  3. Jun 24, 2010 #2

    berkeman

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    Staff: Mentor

    What is the context of your question? In what country? In what point in the power distribution system? Some places they are connected, and other places they are not.
     
  4. Jun 24, 2010 #3

    if three phase motor grounded and neutral are also connected so,
    my question only one can doing all necessary work.

    like safety and all neutral kind of stuff
     
  5. Jun 24, 2010 #4

    berkeman

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    Staff: Mentor

    What country? What voltages? What is the national electrical safety code in your country? In the US, it is the National Electric Code (NEC).
     
  6. Jun 25, 2010 #5

    i am from Pakistan Asia, and voltage is 415 v three phase.
     
  7. Jun 25, 2010 #6
    The neutral acts as a current return path in normal operation whilst the earth acts as a fault current path in the event a malfunction causes the active conductor to come in contact with a conductive part of equipment (assuming it is bonded to an earth conductor). It allows a large current to flow and this in turn trips the protective device.

    In australia, the only place the neutral and earth are connected is at the main switch board. We also use 415V, there may be similarities.
     
  8. Jun 25, 2010 #7
    It's possible to transmit electric power over large distances with just one wire. The earth (ie, the planet Earth) is used as the current return path. But, there's some danger of electrocution for people nearby. So, we normally let the current return over a second copper wire (the neutral). But if the neutral wire is cut, you, again, get a risk of electrocution. So we end up connecting both the earth and the neutral to our appliances (three or four wires in total), which is kind of inefficient. Oh well.
     
  9. Jun 27, 2010 #8
    Neutral is star point of a balance multi phase system, but grounding /earthing is a terminology for explain the connection way of electrical and /or nonelectrical equipment body to earth as a huge electrical conductor. It presents the three earthing systems defined in standard IEC 60364 and used to varying degrees in all countries. Each earthing system is looked at in terms of dependability (safety, maintainability and availability).
    Today the 3 earthing systems such as defined in IEC 60364, are:
    - Exposed-conductive parts connected to neutral -TN-;
    - Earthed neutral -TT-;
    - Unearthed (or impedance-earthed) neutral -IT-.
    The purpose of these three systems is identical as regards protection of persons and property: mastery of insulation fault effects. They are considered to be equivalent with respect to safety of persons against indirect contacts.

    --------------------------------
    Creative thinking is breezy, Then think about your surrounding things and other thought products. http://electrical-riddles.com
     
  10. Jun 27, 2010 #9
    Why is it not the same if you connect the neutral line to the casing instead of the ground wire? Since neutral is connected to ground at the breaker anyway so what's the different?
     
  11. Jun 27, 2010 #10
    In case the neutral wire was wired up wrong. Duh. :tongue: Electrical codes don't always have overwhelming imperative behind them. But they increase safety slightly enough to be worth it. Plus, the electricians unions' get more work for themselves.
     
  12. Jun 28, 2010 #11
    Also it would be less likely (if not completely unable) to identify and interupt earth leakage currents. The earth cable is there for safety, to provide controlled path for faults.

    It's not only equipment that is earthed, steel structure, reinforcing in concrete and metal plumbing are also electrically earthed. This means if an active cable somehow comes into contact there is a low impedance path to ground which will activate any protective devices instead of leaving the window frame 'live'.
     
  13. Jun 28, 2010 #12
    Warning! It is very dangerous; it may be cause the dangerous shock and dying. For description and figure please refer to http://electrical-riddles.com/topic.php?lang=en&cat=7&topic=616"
     
    Last edited by a moderator: Apr 25, 2017
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