Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Does the neutral conductor carry current during normal working condition in a house?

  1. Apr 1, 2017 #1
    I read in a book that during normal working condition (balanced system) the current through a neutral conductor is zero i.e., Ia+Ib+Ic =0 where Ia, Ib, Ic are phase current of three different phases a, b, c. How is that possible? I mean if you look at mathematical result of the phases they are parted by 120' each.
     
  2. jcsd
  3. Apr 1, 2017 #2

    cnh1995

    User Avatar
    Homework Helper

    In a balanced three phase system, neutral current is always zero.
    Plot the phasor diagram and see the resultant. It should be zero.

    In your thread title, you've mentioned residential load. Residential supply is single phase supply and the neutral carries the same current as the phase wire.
     
  4. Apr 1, 2017 #3

    jim hardy

    User Avatar
    Science Advisor
    Gold Member
    2016 Award

    ?? How is it possible?" you ask ? Do vectors add head to tail?
    Get out your drafting tools and add three of equal length separated by 120 degrees .
    You'll wind up back where you started, at the origin 0, 0



    On the incoming wires from the pole to the beaker panel , neutral carries the difference between currents on the two phase wires, in other words the imbalance, just as in three phase.
     
  5. Apr 1, 2017 #4

    cnh1995

    User Avatar
    Homework Helper

    Thanks @jim hardy for that edit.
    I was talking about Indian supply system: 230V with one hot and one neutral.
    So our residential neutrals never carry zero current.

    But as you said, phase and neutral currents are equal indeed "within any single branch circuit".
     
  6. Apr 1, 2017 #5

    jim hardy

    User Avatar
    Science Advisor
    Gold Member
    2016 Award

    Ahh that never dawned on egocentric me ! [ Sheepish grin icon ]
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Does the neutral conductor carry current during normal working condition in a house?
  1. Neutral current (Replies: 2)

  2. Neutral current (Replies: 1)

  3. Neutral Conductor (Replies: 10)

Loading...