Anonymous
Anonymous asked in Science & MathematicsPhysics · 1 month ago

What’s the difference between ground and neutral when it comes to electric?

I’ve had a couple electricity classes back in college and very much enjoyed it.   I have a basic understanding of how electricity works but I was curious what the difference between ground and neutral is.  As far as I remember I think it has something to do with them being similar yet ground is usually isolated from neutral and is the only one truly grounded to earth.  While neutral is more of a reference ground to whatever device is being used.  Not truly grounded to earth but due to it being possible of a few volts difference in earths ground and wherever you are it serves as a ground point as well.   Am I completely off on this thinking?   I’m really just curious is all.

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  • Fred
    Lv 5
    3 weeks ago

    A grounding system is intended to carry current only under a fault... or carry away static electricity or massive amounts of lightning current safely away from people and property.

    A neutral is usually attached to the center tap of a transformer; such as in a 220 / 110 volt system. The neutral wire attached midway at a center tap. Once attached at a load distribution center (breaker or fuse box) the center tap 'neutral wire is attached to a grounding system and (if your an electrician) now referred to as a "grounded conductor". It is grounded to the back of the load distribution box and grounding system.

    To add to the confusion (unless you are an electrician and use that language) the current carrying wires that go to and from the breakers or fuses are called "non-grounded conductors".

    Yeah? Clear as mud... unless you have been exposed to that specific language by an electrician!

    Basically when I talk to a state electrical inspector I will never use the word "neutral" and properly use "grounded conductor".

    • Andrew Smith
      Lv 7
      3 weeks agoReport

      Our 240 V transformers are not centre tapped. They have one active ( non earthed ) wire and a neutral wire that is earthed at the transformer. Giving 370V Peak to earth on the active wire and only the voltage drop along the neutral wire being discoverable there.

  • John P
    Lv 7
    4 weeks ago

    Generally a very low voltage, maybe 1 or 2 volts. It would vary from time to time and place to place - there is no universal answer. I have run a 6 volt flashlight bulb with that set up, but it was generally dim.

  • goring
    Lv 6
    1 month ago

    A ground is a sink for over current especially in a short circuit. Ground is used to maintain same  potential between two circuits.

    A neutral is the point in alternating current that sums the  3 phases and balances them to zero.Each phase is relative to the neutral.  In order to maintain equal potential the neutral is grounded.

  • Steven
    Lv 7
    1 month ago

    Neutral is the return path for operating current.

    Safety ground is the return path for fault / leakage current that holds the body of the appliance to zero volts.

    Neutral is not suitable for safety use because if it becomes open then the appliance would be hot, and it is normal for the neutral to drop a small voltage due to resistance, but mostly because hot and neutral are often reversed by reversing a plug or a wiring mistake, which would make the appliance hot, a shock hazard.

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  • oubaas
    Lv 7
    1 month ago

    Neutral is the star point of a multy-phase system ; ground is a system of thick metal rods deeply driven into the soil and connected together by a thick copper conductor

  • 1 month ago

    The neutral wire is earthed at the transformer.

    Your earth wire is earthed at the house.

    As current flows along the neutral wire volts are developed V = I R

    where I is the total current flowing from the transformer along the wire and R is the resistance of the wire.

    This is typically a few volts.

    But the difference comes if something breaks the neutral wire between you and the transformer.

    Any use of electricity anywhere puts current onto the broken part of the neutral wire. Raising its potential instantly to the full supply voltage.

    Whereas your ground wire is used by no one else, and it normally carries zero current ( except during a fault in YOUR equipment or circuit ).

    So that it remains at zero volts at all times.

    The neutral wire cannot be trusted to do this.

    Of course in our state we have more than 20000km of Single Wire Earth Return wiring.

    To save money they don't HAVE a neutral wire at all. Relying entirely on the earth wire to carry the power back to the transformer.

    You can imagine how any failure in the earth system immediately makes the house deadly.

    Fred, I come from Victoria, Australia and the inspectors are a state issue. SWER systems are completely lawful but after some terrible fires it was realized that these systems can never be made safe.

    So there is an official policy of phasing them out.

    However because of privatization and cost there has been little progress made in this direction.

    I have even seen new SWER systems go in into the Whipstick Forest.

    The thing is that a balanced line system can detect a short to ground and shut down to prevent a fire.

    An swer system uses the ground so it cannot detect the difference between normal load and a spark into the forest.

    That spark starts a bushfire.

    Admittedly there is not earth leakage equipment on all the branches. That should be installed urgently.

    Cheap ubiquitous earth leakage detection would save many bushfires.

    • Fred
      Lv 5
      3 weeks agoReport

      Also it required the additon of emergency stop stations around all the large mill equipment scattered about a three story prefab and pre-wired structure.

  • Roger
    Lv 7
    1 month ago

    Neutral is the return line which completes the circuit. Both the neutral and ground lines are tied together in the main circuit breaker box and are connected to the ground rod. Normally current does not flow trough the ground wire, it is used to protect people from a defective appliance, electrical, or electronic device.. For instance if a washing machine leaks current to its metal case the ground wire will conduct this leakage current away..

    The neutral wire carries current and can break so it is not used as ground wire. The neutral had been used as neutral/ ground in 120/240 outlets ( electric clothes dryers) but not anymore

  • Zirp
    Lv 7
    1 month ago

    Electricity is supposed to flow to neutral, ground is for when something goes wrong

  • Mark
    Lv 7
    1 month ago

    At the first point (literally, at the first point), they are the same... But in spreading out, electricity ONLY flows through the "neutral", under normal circumstances, but in the instance of a short circuit, it flows through both, causing the circuit to "break", so to speak... (This is kind of important, because it can save a life if the breakers gets signals to turn off, it should, right away the grounding wire" normally has NO current going through it, and in the case it does, the electricity goes right back to the source.)

  • Bill-M
    Lv 7
    1 month ago

    Ground or Earth goes to a Earth Stake below the power box.

    Neutral wire goes back to the power plant.

    • Mark
      Lv 7
      1 month agoReport

      To the transformer first, but you are essentially correct. That whole electricity goes to ground means electricity goes to the GROUND to not the literal ground that we walk on... )

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