Comments by "Nhit C" (@nhitc6832) on "The Engineering Mindset" channel.

  1. Seems like a lot of people are interested in knowing how electricity works.
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  2. You can always learn something whether it's beneficial to you personally or not.
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  3. He's using electrons current instead of conventional current. In actuality, eletrons go from negative to positive. But in electrical engineering, conventional current is used. Conventional current goes from positive to negative
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  4. to bring the imbalance current back to the source. No system is truly balanced in practice. There will always be some unbalances between loads. Another advantage for having a neutral is protection for the loads. If one load for some reason stops working, not having a neutral will cause a voltage spike in the other 2 loads potentially destroying the loads.
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  5. It just depends on which system you're familiar with. I understand more about 240/120 system than I do the one used in Europe
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  6. tho you'll get more power the more phases you add, the complexity and the cost to run such system increases significantly. So 3 phase provides a balance between power and cost. It's good enough so to speak.
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  7. Hi, what is not up to code in this video???
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  8. Voltage is always a measurement between 2 points. The neutral is just as live as the other hot legs. People in the trade learned the hard way and get shocked because they ignorantly believe that neutral is always safe to touch.
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  9. that's how the U.S 240/120V split system is configured. The neutral is tap at the center of the transformer splitting the 240V in half.
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  10. because it's easy to conceptualize by pretending current going in one direction. But of course, we all know AC current alternates.
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  11. It has something to do with Kitchoff's current law.
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  12. because ground bar and neutral bar are bonded together inside the panel. So it doesn't matter if the receptacle ground is connected to neutral bar or ground bar. Some panels have a separated ground bar (but still bonded to the neutral bar) simply because they want to group the all the ground wires together making the panel looks neater
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  13. look up Kirchoff's Current Law. It states the the sum of all currents coming into the node equals the sum of all currents leaving the node.
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  14. most modern vehicles have parts that are equipped with diodes, which only allow current to go in one direction. The alternator in your truck converts AC to DC. It is designed so that it allows power to goes from + to -, and other electronics in your truck are also designed to have currents go from + go -. That's why your truck doesn't work if you swap the polarity.
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  15. You can think of the negative side of the battery as a neutral. Both serve as a path for current to return to the source.
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  16. n-phase power will provide constant power, except 1-phase and split phase like the 240/120 system in the U.S
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  17. What you're missing is the neutral is connected to the load. So for current to go through the neutral, it has to first pass through the load (which is higher resistance). The ground is NOT connected the load, current can just go from hot to ground without going through the load. So from hot to ground is very little resistance.
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  18. This is beyond what electricians need to know. But while electrons only oscillate, energy DO flow according to Poynting Vector.
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  19. no we're not. In what way are we behind?
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  20. the ground wire is only bare inside the electrical boxes. But if you take a look at our wires, the ground wire is also insulated.
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  21. Every substance has conductivity. Soils/dirt just happen to have a very poor conductivity.
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  22. there were 2 phases power systems. But they got phased out in the mid 20th century. 3 phase power system became standard.
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  23. how are you doing so far?
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  24. why? because they both need a path back the the transformer to complete a loop. The neutral bar is where all currents go back to, and then to center tap of the transformer. how? neutral an ground are connect to the equipment on one end. The other end is the plug which has neutral and ground, which gets connected to the wall socket, which itself also has neutral and ground that ultimately connects to the neutral bar.
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  25. Voltage is a potential difference betweet TWO points. You're thinking voltage in terms of individuality. That's why. Between neutral and a hot leg, there's 120V. Between neutral and neutral, there is 0V. Between red leg and red leg (also, black leg and black leg), there is 0v. Between black and red leg, there is 240V
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  26. 125A breaker monitors the current on ALL wires coming to the panel. If the current exceeds 120A, it will trip the breaker, cutting the power.
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  27. because single phase plenty enough. 3 phases are utilized in most commercial buildings
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  28. No. whichever wire is connected to Earth and the center tap of the transformer is called the neutral. Suppose in a different system, where one of the legs (red or black) is connected to Earth. That leg would be called "neutral", but this "neutral" will behave differently than the neutral that bonds to the center tap and Earth. Don't pay attention too much to what the wires are called. Pay attention to what they do.
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  29. if the hot leg is tied to ground, that "hot leg" is now neutral. So, if you touch that "hot leg", you will NOT get shock because you're also connected to ground, thus, at the same potential as that "hot leg". However, the neutral in this system is now live. So, what we call a "neutral" is just a matter of what is connected to ground. In the 240/120V split system, the center tap is connected to the ground, thus, any wire that connects to this center tap is called a neutral. But it's more important to understand what a neutral does than what a wire is called.
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  30. Physically, the two legs are at different spots of the coils. One leg is at one end of the coil. The other leg is at the other end of the coil. They are at different potential
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  31. Version 2,3,4 seem unnecessarily complicated. Version 1 is the simplest
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  32. GFCI monitors the difference in currents on hot and and neutral. If there is a difference, it will trips AFCI monitors the waveform of current. Current with no arc fault has a smooth sinusoidal waveform. An arc fault will disrupt this waveform. AFCI detects this irregular waveform and trips.
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  33. it may not be fatal, but you'll get a nasty shock!
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  34. I spent around $300 to learn about DC and AC circuit online. Money well spent! The same cource will probably cost 3 times as much at a university.
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  35. SOME small current will go across the ground and back to transformer in the event if a ground fault. But 99.99% of the current will go through the ground wire. Enough to trip the CB
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  36. Smart switches have neutral.
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  37. more phases create more complexities, which cost more to maintain. Imagine having 6 transmission lines that stretch for thousands of miles in stead of 3 wires. That cost will quickly add up. The cons (mostly cost) just far outweighs the pros, which is more power. Long time ago, engineers just decided that 3 phases are enough power pretty much for anything that uses electricity.
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  38. yeah because we use 240/120 split system.
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  39. My dream job! Unfortunately, i have no degree 😂
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  40. yes. Old dryer utilized the two hot legs via 3 prong outlet (the third prong is just for the ground). However, this 3-prong outlets are no longer up to code. Instead 4-prong outlet is used.
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  41. I think those current are too small to make any difference.
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  42. I thought TN-CS is also common in Europe (not sure about Asia tho). TN-S is too expensive
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  43. I was frustrated i didn't understand electricity. So, I took a circuit analysis course, and glad I did! I understand some stuff even some amateur electricians don't.
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  44. because the transformer is the source.
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  45. it's the Root Mean Square of the sinusoidal voltages. It basically tells you the equivalent DC voltage the results in the same amount of power. For example, given a load, 170V AC will deliver the same power as 120V DC.
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  46. Just color convention. They could have chosen a different color. Makes no difference. They just need to be able to tell which wire is which by their colors.
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  47. Then you need to know the basics first. Learn voltage, current, power, and relationship between them
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  48. If the circuit is balanced, yes, theoretically, you can cut the neutral. But in practice, the circuit is never balanced. Cutting the neutral dangerous as it can causes things to blow up
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  49. I don't think it's complicated at all.
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  50. It's not always safe to touch the neutral. However, if everything is wired correctly, you can touch the neutral because you, standing on the ground (Earth) is at the same potential as the neutral. Same potential means no voltage.
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