I am trying to decide if this video is a better example of bootleg ground issue or bonding. Or both?
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Both. The video is demonstrating what we home inspectors call a “bootlegged” ground created by bonding the ground to the neutral at the receptacle.
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Steve is one of the posters on YouTube who makes videos that are actually correct. A majority of the electrical content on there is incorrect. The bootleg ground demonstration was to show what can happen when you install a bootleg ground and you then lose the feeder neutral. He nailed the part about “first means of disconnect”. That term belongs in the trash bin.
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The bootleg jumper is the problem. But there are so many questions and unclarity about bonding on here. That is what drove my question and was hoping you would respond.
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Yes, NEC Article 250, Bonding and Grounding is one of the most confusing articles partially due to the misuse of some of the terminology which makes it more difficult to understand.
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In this example, if this panel and the primary at the meter were both bonded, would there be any change to what occurred? Instead of at a bootleg, could this happen to a sub-panel bus if it is bonded and the neutral is lost at the splice.
This is not a “bootleg ground.” In a bootleg ground there is no ground connection. The neutral or grounded conductor is simply connected to the outlet ground connection as well without any actual ground wire present. You know this to be true as his very first jumper connection on the outlet creates a spark. Had it been a true bootleg ground he would simply have been jumping the neutral connection to the yoke of the receptacle which was also a neutral connection. An actual physical ground had to be present for a spark to occur (in addition to a load on the same circuit (67 A).
Two things come to mind in this video. One is simply when is 67 amps drawn on (in this case) a 15 amp outlet? The second question is when did he expect his flimsy Radio Shack jumper to burn up?
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You’re right. I certainly misspoke previously. I think what he really created was a true “floating neutral” condition and he demonstrated one of the many hazards of this condition, including bonding to the neutral downstream from the service.
Better than what?
Overall, it is a good video, but it does not address bootleg grounds. Also, he doesn’t explain the reason for the potential between the grounded conductor and the EGC. There would be no potential in a perfect world. But, of course, we don’t live in a perfect world. The difference is because there are different impedances between the two return paths. But, why? There shouldn’t be. That is usually an indication that grounded conductors were indiscriminately connected together in a junction box. In this instance, however, the receptacle outlet is in close proximity to the panel. So, what else could cause a difference in potential? The impedance and current in the jumper is where I’d put my money, based on the information provided, if I were making a wager.
None of that, however, addresses your question. The video is not demonstrating the effects of a bootleg ground. He clearly has two return paths. A bootleg ground, on the other hand, has only one. So, we are now back to my original question to you, better than what? It’s a good video. In fact, it is better than the great majority of electrical videos I have seen on YouTube. But, it in no way addresses bootleg grounds. It does address bonding, but not directly.
A bootleg ground is one in which there is a single return path, not two as in the video. A bootleg ground is where there is no EGC and the grounded conductor is connected, via a jumper, to what is supposed to be an EGC terminal. There is a very big difference between a bootleg ground and what he is demonstrating in the video.
The video depicts an excellent example of why we only connect the Grounded conductor and the EGC together as far upstream as is practical, but it doesn’t address bootleg grounds.
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Coincidentally, another of his videos popped up in my feed that better explains bonding.
Thanks for your answer. So, I guess I will rephrase my one question. Let’s eliminate the jumper that I referred to as bootleg. Could you potentially have the same problems at a bonded sub-panel bus bar if you were to lose a neutral?
Yes. Loss of the neutral is a fairly common electrical system failure. Losing the neutral can cause current to flow on the EGC (which is why it exists) or on other conductive paths either to the source or to Earth.
As he demonstrated in the video, the potential could be, and usually is, very low, but the current can vary. Loss of the neutral is a common and serious problem with electrical systems. He over simplified current flow a little, but his presentation is typical of presentations that are mainly intended for electricians. He acknowledges in the video that engineers may have a different way of explaining the concepts.
Wired magazine did a series of Five Levels of Difficulties videos. The five levels are:
1. A Child (or “Explain Like I’m Five” - ELI5)
2. A Teenager
3. A College Student
4. A Graduate Student
5. An Expert/Subject Matter Peer
Based on that rating system, my assessment of his videos is that he is video is between levels two and three.
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In my opinion, the best way for the majority of people to grasp something is to put it into the simplest terms.
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