Comments by "ke6gwf - Ben Blackburn" (@ke6gwf) on "Ground Rod Explained" video.

  1.  @romuloambay9624  and just like politics and religion, the disagreement nearly always is because of ignorance on one, or often both, sides! People rely on what they have heard others say, and then treat it like gospel truth, where if someone actually wants to learn about a subject and puts the work into truly understanding something, they won't be arguing constantly about it. For instance, it's easy to do a simple test to see if a ground rod will help at all with a ground fault, but most people, engineers included, have never done that, they just accept whatever they were taught, or looked at in theory. Which is why Mike Holt does the demos and goes into such detail in his videos, to try to counteract the ignorance and errors rampant in the industry.
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  2.  @SillyPutty3700  Mike Holt is where I learned the subject! Great source.
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  3. In some soil conditions multiple grounding rods, or complex grounding networks, may be required, in super dry soil, shallow bedrock etc. There are specs for how good the connection is between the earth and the ground rod, and if it doesn't pass something more will have to be done.
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  4.  @WattWireNet  expect you are wrong, because the original Source is also grounded with giant grounding networks, as is the pole mount transformer, so there is a valid (but high resistance) current path back to the Source via the earth, thus the ground wire. Very little current will flow that path due to the resistance, but it will flow. Some utility level systems actually use the earth as part of the circuit, rather than running another wire.
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  5.  @spruce_goose5169  Google SWER, Single wire earth return. I would include a couple links, but YT doesn't always like links. It is not used very much because you get better performance if you add a return wire, it is a common method of current flow at utility scale. So while at household voltages and with household ground systems, earth return is not a practical solution for carrying much current, but when you get to utility scale they are able to do a lot more, because the more current paths you get through the earth, the more current you can get to flow, and if you think about it, the utility has thousands or millions of ground connections, since the neutral wire on the poles has several ground rods per mile creating a vast distributed grounding network. In relation to the Delta system, that's simple to explain. If you put a load between A phase and B phase, you will always have potential, because it's AC, and they are out of phase with each other. You knew that you can run a load across only two phases of 3 phase, right? You don't need a neutral wire to carry current with 3 phase, because the other phases act as the lower potential conductor. But because the Source is always grounded, if you test between a 3 phase power line and the dirt, you will still find it has potential to ground, even without the neutral wire. And the bike chain analogy is a bad one, since electrons take every path available, and are not constrained to only a single physical path. So if you take a wire off the 120v terminal on a utility pole transformer and take it all the way back to the power plant, it will make fireworks because there is a potential difference, despite going through all the transformers in between. If you truly isolate a system, then there is no potential to ground, but utility transformers are not true Isolation Transformers, because they don't provide capacitive isolation, and since the utility grounds the neutral, it removes any isolation that may have existed, meaning that every neutral and every hot wire all the way back to the power plant is tied together electrically, and current flows every available path, including through the earth.
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  6.  @Rk76742  I am not sure if it's a translation error, but the Neutral from the utility is bonded to a ground rod at every pole mount transformer, which in rural areas is at every house. And the Ground rod at the house that's bonded to the Neutral buss has nothing to do with tripping breakers. It's the fact that the Grounding conductor in the house circuit is bonded to the neutral from the utility that gives a high current return path, enough to trip a breaker if there is a ground fault to the grounding wire. You could disconnect the ground rod entirely and it would not effect breaker trips at all
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  7.  @reshpeck  the problem with the water pipe analogy is that the partly full pipe has no resistance. Wires always have resistance, and so the current is always taking all paths.
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  8.  @spruce_goose5169  not accurate. Every Transformer, from the one on the pole by your house all the way back through the substations, to the original power plant, is bonded to the Earth, which while it is high resistance and doesn't let much current flow, is still a valid connection. So while the transformer changes the voltage, the bonded neutral keeps the hot side at a high potential in reference to the original source, via the earth.
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  9.  @spruce_goose5169  of course the distribution neutral is in phase with the house drop neutral! They are both referenced to the Earth, so there is no potential between them. You seem to think that because one transformer is only wound with a single coil going "up" from the neutral, and another transformer has a coil going out from each side of the Neutral, that somehow that makes the Neutral different, but it's still referenced to the Earth, which means that it's the mirror image 110v coils that are moving, not the neutral. As long as you stay within normal operation ranges, there is no isolation across the transformer, because any voltage changes, frequency changes, etc, created by the generator will directly show up at the house, just transformed to a different balance of voltage and current. And yes, the Source always stays as the original generator, because that's where the energy, the Force is coming from, and so when Styropyro turns on a death ray, the generator slows down, because no matter how many transformers there are in between, the energy flow is coming from, and returning to, the generator, and if you stick a hot wire into the dirt at your house, some of those electrons are going to flow directly back to the power plant.
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  10.  @spruce_goose5169  you may not understand this, but in order for current to flow, there has to be two conductors to make a complete circuit, so your idea that Current can flow between separate generators or grids that are only connected by one conductor (the Earth) is pretty funny. That said, if a wire is connected between grounded remote systems, you will have a potential between them, or if they are in sync in frequency and voltage they will just both work to share the load. But in a system with a high voltage wire connecting the systems, with the generator grounded and each substation transformer grounded, as well as the neutral wire a few times per mile, a ground fault anywhere on that system (sourced from that grid) will return to every ground point on the grid, though if there is a nice big fat copper wire as one option most of the current will flow on it, but the other paths still exist. And while the transformers may have some isolation properties, the inductive coupling is strong enough to move the current, and the secondary sides are Earthed, thus eliminating any isolation the transformer may have provided, again making the second circuit path through the earth. My purpose of mentioning the SWER systems is to show that the earth is a very valid conductor, and can conduct actual usable current. What most people don't understand is that the Earth is actually effectively a perfect conductor, zero resistance, due to its massive size and nearly infinite current paths, each taking a tiny bit the current, so the only resistance in the circuit is the contact resistance at the ground electrodes, and so if you put in enough ground electrodes, grids, plates, networks, etc, especially if you are using salt pits, charcoal, or the other water retention ground conduction improving compounds, you can get very low contact resistance, and actually get lower resistance through the ground than through a wire. Now a couple of ground rods at your house are going to have a high enough contact resistance that will prevent much current from flowing, but the Utility grid will have almost perfect grounds as a result of having so many ground points, and engineered grids etc at substations, power plants, etc.
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  11.  @abpsd73  that's basically what he said. It keeps the Neutral Referenced to the earth, keeping a 0v potential between the Neutral, Ground, the earth, water pipes, etc. If you don't reference the Neutral of a transformer to earth, you will still get 110/220v etc out of it, but any leg could end up being at earth potential, or it could be somewhere in between. I have worked on systems where they forgot to Bond the Transformer neutral, and every night when a shorted out photocell controlled light switched on, Neutral would become 120v to ground, and the hot would be 0v to ground, because the lamp was doing the Bonding... That was a fun one to diagnose! Lol
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  12.  @abpsd73  good detective work! Lol My story was an industrial machine room that was fed with 3 phase and then had a floor transformer to provide the 110/220v panel supply, and I discovered it by melting the tip off a screwdriver that bridged a ground strip to a cabinet case one evening, but then when I tried to test it and figure out why the next day, everything appeared normal! It took me a few days until I was in the room at dusk and heard the lighting contactor clunk that I made the connection and then discovered that I could make it flip when I turned the correct breaker off and on. The site rep didn't believe me, didn't think it was possible, so I shut a breaker off, and clipped a jumper wire from the hot terminal directly to the ground buss, and said "watch this!" and flipped the breaker on while he screamed at me to stop! Then after nothing happened, I used the tester to show him how the voltage was flipping, and he finally agreed to get the regular electrician to come in, and I guess he was embarrassed when he was told he hadn't bonded the transformer lol (I was dealing with the industrial automation systems.)
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