Comments by "GH1618" (@GH-oi2jf) on "The Engineering Mindset" channel.

  1. The neutral is tied to ground. Current has nothing to do with the question.
    1
  2. 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.
    1
  3. I don’t see what you mean by “hot source,” exactly. The center tap of the secondary is held at ground potential. The neutral conductor in the panel is connected to the center tap, and to ground, so it is likewise at ground potential. The neutral conductors are not considered “hot” because they should always show zero potential to ground.
    1
  4. 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.
    1
  5. 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.
    1
  6. 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.
    1
  7. “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.
    1
  8. Winterfell — They are in parallel, so lower the resistance, increasing the current.
    1
  9. It’s 3A, not 3V.
    1
  10. The distribution networks in North America are 3-phase. A transformer for residential service is connected to only one phase.
    1
  11. We used to change Hz with motor generators for computer power.
    1
  12. if you have a 4-prong plug, one of them is the neutral, which you don’t have in Germany. You need a neutral to get the 110V used by some parts of the dryer. Probably only the heating element takes 220V.
    1
  13. In this context, “hot” means that it has line voltage with respect to ground.
    1
  14. Sure. So?
    1
  15. 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.
    1
  16. Lightning tries to equalize the charge. When there is a large potential between clouds and the earth, lightning will occur.
    1
  17. You would have to rewire with three-conductor cables and change the receptacles. It is common to upgrade the wiring in old houses.
    1
  18. The breakdown voltage of the insulating materials in an electrical system is much higher than 240V. If your main breaker is 60A, you can’t have an 80A load. The breaker would trip.
    1
  19.  @fnscomedycrew — If you had two identical 40A loads on opposite sides of the system, the neutral current would cancel out and the main breaker would see a 240V 40A current, which would not trip the breaker. If the two loads were on the same side, you would have 80A and the breaker would trip.
    1
  20.  @fnscomedycrew — This is not 3-phase. You are just making it more complicated by discussing 3-phase, which doesn’t apply.
    1
  21. Current does flow in the neutral.
    1
  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.
    1
  23. There are other videos on that subject. I just watched one from Benjamin Sahlstrom.
    1
  24. Adding loads in parallel increases the current. That’s like adding more lanes to a freeway.
    1
  25. Voltage is a potential difference between two points. Used for what? Ground wires have a specific purpose.
    1
  26. Bokhalid al3nizy — You have to consider the entire Earth with its atmosphere as a system.
    1
  27. InstaLabSparti — It was just an illustration. Try to understand the point he was making.
    1
  28. 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.
    1
  29. 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.
    1
  30. The neutral is grounded at the transformer and at the panel.
    1
  31. You might step on a worm.
    1
  32.  @KB4QAA  — That is not correct, either. Such terms just obscure the subject, in my opinion.
    1
  33. On automobiles, you mean. In his diagram, it can be whichever way he prefers.
    1
  34. We (in the USA) have 277/480 3-phase for customers who need it.
    1
  35. The “hot” wire is the one not connected to neutral. The “neutral” is connected to the center tap of the transformer and is the grounded conductor. The ground wires connect the metal parts which do not ordinarily carry current to Earth. The neutral is a current-carrying conductor in normal operation. The grounds are not.
    1
  36. Your ground fault circuit interrupter wouldn’t work. If you don’t have one, you better get one befre you kill someone with your faulty wiring.
    1
  37. The wire that we use in North America for a 20A circuit is #12, about 2 mm in diameter. The wire used in the UK for a 10A circuit is about 1.4 mm, so our wires are not twice the diameter. The UK also uses 2.5 mm diameter wire, so it depends on what is actually used.
    1
  38. 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.
    1
  39. 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.
    1
  40. Minsk Lit — They were trying to become one.
    1
  41. The meter is powered by the current in the wires supplying the customer.
    1
  42. It is a single phase transformer with a center-tapped secondary. Conceptually, it delivers two phases of 120V with a phase angle of 180°.
    1
  43. The electromagnetic field propagates the signal from the moving electrons at near the speed of light. The electrons, the charge carriers, don’t move from the source to the destination. There are free electrons everywhere in the conductors which are influenced by the field.
    1
  44. The “neutral” is the conductor connected to ground, by definition. It doesn’t matter where it is.
    1
  45. Receptacles typically have a ground wire which is distinct from the neutral wire. The ground wire is connected to the ground bus, although in a main panel you may see the ground and neutral bus bars used interchangeably.
    1
  46. There is another video which explains split phase service. The secondary has a center tap, which makes it, in effect, have two secondary windings.
    1
  47. Hire an electrician.
    1
  48. Some transformers have two input bushings. The primary always has two connections. When there is only one input line, the other end of the primary is connected to the case, which is connected to ground.
    1
  49. The primary is powered by one phase of the distribution 3-phase system, which is several thousand volts. The secondary is 240V.
    1
  50. The multiplier is 10^18.
    1