Comments by "GH1618" (@GH-oi2jf) on "Ground Neutral and Hot wires explained - electrical engineering grounding ground fault" video.

  1.  @j5892000  — Copper for a ground wire throughout a large commercial installation built using conduit would be an unnecessary expense. The conduit is a sufficient ground conductor. How the connection is made to Earth is a separate matter.
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  2. Ted Danville — There is a difference between the hot and neutral wires but not in the electricity they carry. The “neutral” is a current-carrying wire which is held at ground potential. A “hot” wire has a potential difference from the neutral.
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  3. Lakshmanan R — You are wrong. The 120V nominal voltage is an average (RMS) voltage. If you compare the waveforms instantaneously, using an oscilloscope, you will see that the voltage is alternating 180° out of phase at one node compared to the other. When one is high, the other is low, and vice versa.
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  4. You can’t just legislate words out of existence. Especially jargon.
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  5. No Reply — You have the idea. The ground is connected to neutral only at the main disconnect. Ground Fault Circuit Interrupters are in the individual circuits, so if one trips you need only diagnose that circuit.
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  6. The breaker trips if the current is too high, unles it is a GFCI type, in which case a very small difference in line and neutral current will trip the breaker. The vertical rectangles with cicles n them are bus bars. Each circle is a connecting point for wire.
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  7.  @c.rogers4464  — You have no idea how this works. You must have been listening to Veritasium.
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  8. Voltage is only detected between two points. You are measuring the potential difference. Current flows on the hot and neutral wires.
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  9. You need an electrician who is familiar with the electric power system used where you live.
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  10. The problem is, water as you are likely to find it outside of a laboratory is easily contaminated with substances which will make it conductive.
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  11. The neutral is tied to ground. Current has nothing to do with the question.
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  12. Generally there is a neutral wire in the distribution network. The transformer primary is connected to the neutral and to one phase. The neutral is grounded at the pole.
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  13. Jack B — No. A hot wire is one which has a potential difference from the neutral. In AC circuits you don’t have positive and negative poles, because the potential is alternating.
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  14. Giulio Costantini — The neutral is connected to ground for safety. The maximum (RMS) potential relative to ground is thereby 120V. Household current isn’t really 2-phase, it is a single phase split into two halves. The neutral from the transformer to the meter is often aluminum. In the US 3-wire system, the hot wires are at 240V relative to each other, so the same as much of Europe. Another way to look at is that one of the two hot wires is carrying only about half the load. The power company will often size the wires used to deliver power to the actual load, not the theoretical maximum load. If you want to save copper you should switch to 60 Hz and get more efficient transformers.
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  15. A battery can be hooked up either way. In the 1950s, some US cars had positive ground. Cars today are negative ground. They both work.
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  16. “Hot” is not tied to polarity. For a battery powered circuit, the hot terminal would be the one that is not grounded. Cars used to be made which were positive ground. I think all cars are now negative ground, so it can be either way.
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  17. Sure. So?
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  18. Tejas Dhamnaskar — In my opinion, the author is confusing things by drawing circuits with batteries in an explanation of AC power systems. You are better off just skipping this segment. The neutral is the current-carrying conductor which is tied to ground. That’s all there is to it.
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  19. Lightning tries to equalize the charge. When there is a large potential between clouds and the earth, lightning will occur.
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  20. You would have to rewire with three-conductor cables and change the receptacles. It is common to upgrade the wiring in old houses.
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  21. Current does flow in the neutral.
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  22.  @tiortedrootsky  — In that example, the L1 and L2 loads are balanced, so the currents cancel. In the more general case, the neutral carries the difference in the two hot line currents.
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  23. There are other videos on that subject. I just watched one from Benjamin Sahlstrom.
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  24. Voltage is a potential difference between two points. Used for what? Ground wires have a specific purpose.
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  25. Bokhalid al3nizy — You have to consider the entire Earth with its atmosphere as a system.
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  26. InstaLabSparti — It was just an illustration. Try to understand the point he was making.
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  27. You have the terminology wrong. The “neutral” is the conductor which is connected to ground. The “hot” conductors are not. It has nothing to do with direction of current.
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  28. Han Lee — Wrong. The neutral wire is never “hot” (unless something is wrong!) because it is held at ground potential. “Hot” refers to potential difference from neutral, not to current.
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  29. You might step on a worm.
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  30. On automobiles, you mean. In his diagram, it can be whichever way he prefers.
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  31. ironmatic 1 — If it connected to ground through a high resistance, the breaker might not trip. A GFCI breaker would detect the leakage and trip.
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  32. NetworKing — Actually, when one hot wire is at 120V, the other is at -120V. When one is zero, the other is zero. They are 180° out of phase. The neutral is tied to ground so should always be at or near ground potential. On a polarized outlet, when wired correctly, the wider slot is connected to neutral. Some devices, including ordinary lamps, should use a polarized plug to ensure that easily accessible parts will be connected to neutral, hence at ground potential.
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  33. Minsk Lit — They were trying to become one.
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  34. The “neutral” is the conductor connected to ground, by definition. It doesn’t matter where it is.
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  35. Hire an electrician.
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  36. The neutral conductor is always at or near ground potential if there are no faults.
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  37. Everything with batteries is irrelevant in a discussion of AC wiring. In automobiles, the negative terminal of the battery is connected to chassis ground, but this is just a convention. There were some positive ground automobiles long ago.
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  38. You had better not.
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  39. Electronics is a different field with its own conventions. There are two symbols, one for chassis ground and one for Earth ground.
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  40. It will probably blow the filament in the lamp.
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  41. The GFCI compares the hot and neutral lines of its circuit and opens if there is a significant difference. A difference is an indication of a ground fault. I don’t know what you mean by “residual.”
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  42. The transformer secondary is the source of electromotive force. The neutral is grounded at the pole supporting the transformer and also at the customer’s service panel. Current normally flows in the neutral to complete a circuit with one of the supply lines, but if you touch a “hot” line you will make a circuit through the ground.
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  43. He is only concerned here with the customer side of the transformer, so has not explained the utility (primary) side fully. In the North American system, one side of the primary is connected to one phase of a 3-phase “WYE” distribution network. The other side is connected to the neutral of the 3-phase distribution network. The neutral of the secondary is connected to the 3-phase neutral, and to ground, so the neutral is connected from the substation to the customer’s wiring. You will often see only a single insulated bushing on the top of a pole-mounted transformer because the enclosure of the transformer is tied to neutral. The neutral wire is generally placed on the poles below the transformer, where it will be connected to the neutral terminal on the transformer.
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  44. The code does not specify the orientation. Most people, including electricians, install them with the ground pin at the bottom.
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  45. wrong. There is a distinction. The neutral is a grounded current carrier.
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  46. If you are standing on the ground and touch an ungrounded conductor which is “hot,” you will have made a path for a current from the hot wire through your body to ground. “Hot” means that there is a potential difference from ground.
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  47. Electrons are charged particles. Like charges repel, so when the power company pushes electrons into the wires, the electrons already in the wires (the ones least tightly bound, that is) move along. Electrons don’t know anything about the source, they are just trying to equalize the forces on them caused by the charge imbalance. As it happens, the path of least resistance leads to another wire back to the transformer, so they move toward the source.
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  48. I call it “line.” We have free speech. Call it what you please.
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  49. Tubmaster 5000 — Ok, but was the neutral tied to ground at the service panel?
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  50. No. If you have 3-phase service, you have three hot wires. Some places might have only single-phase service. The US had single-phase AC before we developed the split-phase system.
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  51. Wrong. This has been explained before. The neutral wire is the grounded conductor. It is always neutral. The “hot” wires have a significant potential difference from ground and the neutral conductor. They are always “hot.”
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  52. TheBaconBoss — The terminals are not “positive” and “negative” in AC. His demonstration using a battery could be done with it connected either way. It was just an illustration.
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  53. The center tap is called “neutral” by the manufacters of transformers, by linemen, by manufacturers of load centers, and by electricians. You can find that usage everywhere.
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  54. GEORGE — The neutral is held at ground potential. You don’t feel current in a wire. You feel current that leaves the wire and goes through you. That will only happen if there is a potential difference between the wire and the thing you are standing on.
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  55. I agree. Why use AC terminology in a battery circuit? Why use a battery in a discussion of AC?
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  56. The neutral wire is at ground potential. To be electrocuted, you must touch two conductors which have a high potential difference between them, so Earth and neutral doesn’t do it. Neutral and one of the hot lines will, however.
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  57. YotaXP — For one thing, you couldn’t have a GFCI to detect faults. The GFCI protects you if you are carrying current.
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  58. dubyajayyo — The ground wire in the circuit will generally be copper and the same gauge as the other wires. It is more conductive than the human body. If you are touching the exposed metal parts of the system, such as the breaker box, then some event applies voltage to those metal parts, you want the resulting current to be carried to ground through the ground wire, not through your body.
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  59. That’s not correct. Electrons are charge carriers. You have to have moving charge to have electric current. They don’t move far in a half-cycle, but there must be a net movement of charge.
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  60. Unfortunately, “conventional current” was defined before the discovery of the electron.
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  61. The ground and neutral are connected at the main panel.
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  62.  @johnjones8412  — Your point is unclear. Power does come from the power company.
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  63.  @johnjones8412  — The electric power is produced in dams, or byr burning coal or natural gas, or in fission reactors. It can also be produced by wind turbines or solar panels. No energy is created, it is merely converted to electric energy from other forms of energy.
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  64. Devin Doiron — There is no discussion of 3-phase ar 5:03.
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  65. Yes, they do, but not very far in AC. The electrons are charge carriers. You have to have moving charge to make a magnetic field. Conductors enable electric current because they contain loosely bound electrons which can be dislodged by electromotive force.
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  66. It should mean the opposite. If your wiring was done correctly, the potential from neutral to ground should always be negligible.
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  67. Fellzer — Think of two lumberjacks cutting down a tree with a long saw. They alternate pushing and pulling.
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  68. Ralph Averill — The legs (hot wires) are not connected to phases. The primary of the transformer is connected across any two phases of a 3-phase distribution line. The secondary of the transformer produces single phase, 240V power. The secondary is tapped in the middle and used as the neutral, which gives two 120V single phase power sources. The two 120V legs have opposite phase.
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  69. Dialectical Monist — The center tap in the transformer secondary is not a short because of the resistance (actually impedance) of the wires in the secondary. The secondary can be thought of as two 120V transformer secondaries connected in tandem.
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  70. The neutral is always at ground potential, but current flows both ways. The flow changes direction 100 times per second (50 Hz) or 120 times per second (60 Hz).
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  71. No. “Hot” means that there is a potential difference (voltage) with respect to ground. Direction of flow is irrelevant.
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  72. M — They should be the same, except for color.
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  73. Every wire has some resistance. Load has nothing to do with it. We commonly say resistance instead of “resistivity.”
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  74.  @andreasolin8520  — The wire is just part of the load, but an insignificant part, normally. We (in the USA) seldom worry about the resistance of the wire. We think about the maximum current and the code requirement. For example, for a common 20A circuit with receptacles we use #12 solid copper wire.
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  75. That diagram is not helpful, in my opinion. “Neutral” is term generally used in AC circuits, and the neutral is grounded. There is no ground in that illustration. If you want to understand AC electricity, I recommend you disregard any illustration with a battery in it.
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  76. Earth ground is important. If you get a shock because of lack of a ground, it’s no laughing matter.
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  77. Appregator — So?
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  78. groove jet — “Conventional current” was defined before atomic structure was understood. When working with electricity at a practical level, it is better not to worry too much about the physics.
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  79. We don’t have one per plug. Ideally we would have one per circuit, but only new construction is likely to have that many.
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  80. Same thing.
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  81. Ignore everything with a battery.
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  82. In cars, we use negative ground, meaning chassis ground. There used to be cars with positive ground. It’s arbitrary, so just a convention for automotive electrics.
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  83. You have to use a GFCI breaker which supplies both circuits.
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  84. You are charged for energy, which is the product of voltage and amperage, integrated over time. The electrons aren’t consumed, but they are pushed back and forth in the wires. In the process, they do work. You are charged for the work, which is energy.
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  85. It isn’t a particularly good way to describe it, so most people don’t use that model.
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  86. Yes, “source” is a confusing term. By convention we ground the center tap of the transformer and call that “neutral.” From the standpoint of the circuit, the hot and neutral wires are equivalent. From the standpoint of a person standing on the ground, the hot wire is the one that will give you a shock if you touch it.
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  87. There is no fixed positive and negative in AC. In illustrations with batteries, he uses electron flow rather than conventional current. It doesn’t matter, really. Better to skip that part, in my opinion.
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  88. No. “Neutral” is the center tap of the transformer secondary.
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  89. Most houses were built berore GFCI existed, and more were built before GFCI was required. In the US, we generally enforce new codes only when new work is done.
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  90. Kelly Brown — It’s a metaphor. Current is not exactly like water flowing in a pipe, but it is a useful analogy. When working with electrical circuits at this level, it is not necessary to understand electrons the way a physicist understands them. You can obtain a practical understanding of electricity without understanding atomic physics.
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  91. Gerald Foster — It is better to not get hung up on the physics when studying electric power, especially for AC.
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  92. Ken McCandless — I can’t believe many people will give up their terminology for NEC terminology, especially since the three NEC terms are so similar. EE Times noted that mistakes have been made because of the poor nomenclature.
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  93. Electricity does not choose just one path or the other. It follows all paths, dividing in proportion to the conductance. If you are standing on damp ground and touch a hot wire, enough current will be conducted to do serios damage. It is best not to test this proposition.
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  94. Everybody calls it neutral.
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  95.  @3328music  — Sure, but the vernacular is not determined by official documents.
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  96. For one thing, you couldn’t tell when you have a ground fault.
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  97. The field is stronger in the hot wires.
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  98. Electricity will move as needed to equalize the charge. To start with a simple example, if the current path contains two resistors in parallel, the current will go through both, but will be divided in inverse proportion to the resistance. This can be generalized to any number of resistors. In a power distribution system, the neutral wire is a low resistance path back to the transformer — much lower than the path through the earth. Some current would flow through the ground path, but it would be insignificant.
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  99. kunal patil — Please give a time indication.
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  100. A ground wire might have larger diameter.
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  101. To understand this, ignore every statement about “returning to source” or “used electricity.” The “neutral” is the conductor connected to ground, so the potential difference (voltage) between neutral and ground should always be near zero.
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  102. The neutral is held at ground potential.
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  103. This is evidence that this is not the best way to explain AC. There seems to be a lot of confusion. It is better to forget about “positive” and “negative” altogether and to disregard all the parts dealing with batteries. Just think of electricity always running in a circuit. In the North American system, there are three circuits you can draw from the transformer to the customer equipment. Draw just three loads: one across the two “hot” lines, and one each across one “hot” and the neutral. The first is a 240V circuit; the others are 120V. The current will flow in both directions, but at an instant in time, the flow in the “Hot” conductors will be in opposite direction, one out of the transformer and one into the transformer. The current in the neutral will be the difference in the two 120V currents, because they flow in opposite direction.
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  104. Once you have drawn those circuits, forget about electrons and polarity. The only thing you need to know about polarity is that the 120V circuits run with the 240V circuit in the hot legs and against each other in the neutral. Now you just assume a current for each circuit and you add them in the hot legs and subtract the 120V currents in the neutral. You just think of the three circuits as being superimposed. Think that over for a while and try not to worry about what the electrons are doing. The electrons are for physicists. Then ask another question based on this model.
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  105. Tesla was bright, but his idea for transmitting power wirelessly was cockamamie. His great mistake was in not recognizing that the best use of radio was transmission of information.
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  106. “Hot” means there is a potential difference to Earth.
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  107. The US started with 110VAC. The split-phase system was invented to get 220V while remaining compatible with the existing system.
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  108. bootlegapples — If you go forward a few seconds, you will see a 120V light circuit using the upper hot line. You could add a second light circuit using the lower hot line.
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  109. Better to skip the part about batteries.
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  110. Jonathan H — Why do I keep thinking of Pac-Man?
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  111. Tran Quoc Lan — No, that’s not a correct explanation. The current flows in both directions through both wires. The neutral is a current-carrying wire which is held at ground potential. It is always the same wire.
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  112. Electrons do move in the wire or there would be no field.
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  113. Sheldin Maumkel — No! The video is correct. That is where you get your 240V circuits. The two bus bars are connected to opposite poles of the transformer secondary.
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  114. So he is unconventional. I’ve never liked that convention myself.
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  115. No, the neutral wires are part of the circuit (except for a 240V load). There are three wires from the transformer: L1, L2, and N. There are three possible circuits: L1-L2 (240V), L1-N (120V), and L2-N (120V).
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  116. L1 and L2, the two ends of the secondary, are “hot.” Neutral is held at ground potential so is never “hot.”
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  117.  @j5892000  — Yes, “hot” means it will shock you, in practical terms. You should not get a shock from neutral, even though it carries current.
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  118. “Neutral” has nothing to do with current. The neutral is the part of the circuit that is held at ground potential. A “hot” wire is one that has a significant potential relative to ground.
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  119.  @thelaserdoc1  — Practical electricity is not physics. It is not necessary to understand the physics of electricity in order to have a good understanding of practical electricity. In fact, some people get misled by thinking of physical details. I don’t say this as an endorsement of the way it has been presented here, however. I do agree with the point you are making, though, except the electrons are everywhere in the circuit, not the “field.”
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  120. There isn’t a “positive” pole in an AC panel. In a North American 3-wire system, there are two “lines” and a “neutral.”
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  121. There are always two connections to the primary coil on the transformer, but there may be one or two bushings on the top for the primary connections. When there is only one, the other end of the primary is connected to the case, and the case is connected to ground. In my neighborhood, the transformers are conventional, with two bushings on top. It is conceptually simpler to leave this detail out, because the video is not about distribution systems.
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  122. Biggup — I think it would have been better to leave batteries out of an explanation of AC electrical circuits. They are just confusing some people.
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  123. “Bonding” is connecting the neutral bus to the box. The box is supposed to be connected to Earth.
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  124. There can only be a potential difference between two points. The neutral is zero with respect to ground, but 120V with respect to either hot line.
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  125. Electrons are charged particles. They just respond to other charges.
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  126. Jesse Desjardins — If the entire secondary were floating, I don’t know what the nodes would be with respect to ground, but, yes, the center tap must be grounded.
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  127. The potential between the two lines is 240V. The potential between either line and neutral is 120V. The current cancels on the neutral, and it then is equivalent to two 120V lamps in series on a 240V supply.
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  128. “Hot” does not mean current carrying. A “hot” wire is one with a significant electric potential relative to ground. A “neutral” is held at ground potential. The neutral is a current carrying conductor, but should always be at or near ground potential. In an automobile, with DC electrics, current practice is negative (chassis) ground, but there have been positive ground automobiles. “Hot” is the side which is not grounded.
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  129. Polarity has nothing to do with it. A “hot” wire has a potential difference from ground.
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  130. james ortega — There should be only one GFCI in the circuit.
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  131. I think the answer you want is “C”. In the US, white is used for a neutral conductor, and the neutral should always have a very low potential relative to ground.
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  132.  @qmelectricitypham8455  — It’s just a convention, though.
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  133. Impractical will — Because the neutral is held at ground potential. If you are standing on something which is at ground potential, the potential difference is zero.
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  134. Jimmy — Wires don’t carry volts, they carry amps. Volts are the potential difference between a point on the wire and some reference point elsewhere. Because the neutral is tied to ground, and because wires have low resistance, the neutral should be near ground potential whetever you measure it.
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  135. “Neutral” is the conductor connected to ground; “hot” conductors are not. It has nothing to do with current. That’s all there is to it.
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  136. Pedro Hernandez — “Hot” does not imply a particular polarity. It means there is a potential difference compared to the neutral (or ground).
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  137. I don’t see anything labelled “line” and I don’t see anything wrong in that illustration. Correction: there is one thing wrong. The illustration shows current on both “hot” buses, when there is a load on only one side.
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  138. Michael Edenfield — The waveform of the potential difference across two hot nodes of a 3-phase Y will just be sinusoidal. You wouldn’t know it came from a 3-phase grid.
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  139. A ground wire is supposed to be connected to Earth. He shows that connection in the video. The Earth connection is made at the main panel or first disconnect.
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  140. Robert Brandywine — “Neutral” is not about current, it is about potential. The neutral is held at ground potential.
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  141. In fact, automobiles used to be positive ground. It’s arbitrary.
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  142. Aaron Fitzgerald — The neutral is always at ground potential, which is halfway between the two lines.
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  143. In that particular situation, it would, but you do not want to interrupt the neutrals.
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  144. No. “Neutral” is the conductor connected to ground, by definition. “Hot” conductors are never connected to ground. Current has nothing to do with it. The “hot” wires are always “hot”, meaning that they have a potential difference from ground (unless disconnected).
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  145. Do you mean if it weren’t connected to the ground bar in the panel? It wouldn’t matter. The neutral is grounded at the pole, so if your panel were not connected to ground, the circuit would be completed through the Earth to the neutral at the pole. If your panel were not grounded, it would not meet code.
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  146. Current has nothing to do with whether a wire is “hot,” either DC or AC. A “hot” wire has a significant potential difference from ground. That’s all.
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  147. Electrons are attracted to a positive charge and repelled by a negative charge. They move until the charges are balanced.
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  148. guruprasad gawali — But the neutral must be tied to ground somewhere, isn’t it? Certainly at the transformer.
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  149. guruprasad gawali — In US system, ground is also connected to Earth. We tie neutral to ground, not ground to neutral. Same thing, but a different way of looking at it. Are you saying your neutral is floating?
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