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Thread: Neutral and grounded conductor pertaining to the same thing

  1. #1
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    Question Neutral and grounded conductor pertaining to the same thing

    I thought that I read something regarding the definition of the Neutral conductor. I have searched but to no avail.

    A definition that I found is such:
    Neutral -The grounded junction point of the legs of a wye circuit. Or, the grounded center point of one coil of a delta transformer secondary. Measuring the phase to neutral voltage of each of the normal three phases will show whether the system is wye or delta. On a wye system, the phase to neutral voltages will be approximately equal and will measure phase to phase voltage divided by 1.73. On a center tapped delta system, one phase to neutral voltage will be significantly higher than the other two. This higher phase is often called the "high leg".

    Grounded Conductor - A system or circuit conductor that is intentionally grounded, usually gray or white in color

    Technically speaking:
    Would it be wrong to refer to the white or gray conductor installed to a device or lighting fixture as the neutral?
    Is term neutral pertaining to the grounded conductor?

    Thank you,

    Justin J. Walecka
    still commited to non violence and passive resistance

  2. #2
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    "Technically speaking:
    Would it be wrong to refer to the white or gray conductor installed to a device or lighting fixture as the neutral?
    Is term neutral pertaining to the grounded conductor? "

    A neutral is not always a grounded conductor and a grounded conductor is not always a neutral.
    A 120/240 3ph 4 wire high leg service has a grounded conductor that is not a neutral.
    A 120 volt circuit has a grounded conductor but no neutral.
    I use the term grounded neutral conductor.

    Understanding what a grounded conductor is important. There is an entire article in the NEC on it, Art 200....
    Moderator-Washington State
    Ancora Imparo

  3. #3
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    Tom,

    I would argue that the grounded conductor in a 120/240V service is a neutral if we consider only the 120V legs. If however, we consdier the entire delta circuit, there is, as you say, no neutral.
    Don't mess with B+!
    (Signal Corps. Motto)

  4. #4
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    Tom Baker and Rattus,

    Thank you for the feedback on my potentially inane question.
    Not sure were I'm going with this... If I said install the neutral to the receptacle would that be incorrect. Technically speaking.

    Justin J. Walecka
    still commited to non violence and passive resistance

  5. #5
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    Possible addition to the 2008 NEC:

    5-36 Log #1554 NEC-P05 Action: Accept in Principle
    (100.Neutral Conductor and Neutral Point)
    __________________________________________________ _____________________________________________
    Submitter: Technical Correlating Committee on National Electrical Code®
    Panel Meeting Action: Accept in Principle
    Add the following (two) definitions to Article 100 as follows:
    Neutral Conductor. The conductor connected to the neutral point of a system that is intended to carry current under
    normal conditions.
    Neutral point. The common point on a wye-connection in a polyphase system or midpoint on a single-phase, 3-wire
    system, or midpoint of a single-phase portion of a 3-phase delta system, or a midpoint of a 3-wire, direct current system.
    FPN: At the neutral point of the system, the vectorial sum of the nominal voltages from all other phases within the
    system that utilize the neutral, with respect to the neutral point, is zero potential.
    Panel Statement: The revised wording removes the term “circuit” as was pointed out in the TCC ballot, there is no
    definition for a “circuit conductor” and the “neutral conductor” could be in a branch circuit, feeder or otherwise. The
    revised text also establishes a differentiation between the “neutral conductor” and the “equipment grounding conductor”
    which are in fact both ultimately connected to the neutral point of a system. The differentiation is that under some
    normal conditions, the “neutral conductor” is expected to be current carrying while under normal conditions the
    equipment-grounding conductor is never a current carrying conductor.
    Bryan P. Holland, MCP

  6. #6
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    From Justin
    "If I said install the neutral to the receptacle would that be incorrect. Technically speaking."


    The white or gray conductor that is installed with the switchleg to a lighting fixture is "technically" not a neutral conductor, it is a "grounded" conductor. This conductor will carry the same current as the switchleg.



    A neutral conductor would be installed with at least 2 phase conductors (2 phase conductors on a single phase, 3 wire system), (it could be 3 phase conductors on a 3 phase, 4 wire system), (or it could be 2 phase conductors on a 3 phase, 4 wire system).
    Instructor, Industry Advocate

  7. #7
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    Mr. Holland and Pierre,

    Thank you for your time.


    Justin J. Walecka
    still commited to non violence and passive resistance

  8. #8
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    I'll add that in a 120 volt circuit, we all probably know that the white wire is a grounded conductor.

    With that said, almost everyone I know refers to it in the field as the "nuetral" conductor. They know it's not a nuetral, they know it's a grounded conductor, it's just common slang. Albeit incorrect.
    Formerly J Erickson as username.

  9. #9
    I have always inferred that the neutral wire was named because it is tied to ground and therefore has no potential on it with respect to ground. Kind of like a neutron has a neutral charge.

    Also the neutral is a wire that is supposed to carry current under normal conditions instead of fault conditions.

    A ground should not carry any current accept during fault conditions.

    The definition listed earlier calls for the vector sum to equal zero. But I don’t see why that need be
    I don’t see why a single AC voltage source would not have a neutral if one of the current carrying conductors were tied to ground.

  10. #10
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    IEEE definition

    IEEE dictionary defines the neutral as the conductor with an equal potential difference between it and the other output conductors of a 3-wire or 4-wire system. (so on a wild leg 120/240V system, for instance, there is a grounded conductor but not a neutral)
    Steve Arne
    Training Director
    AETech Electrical Training Center

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