current returning to a different source

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Different strokes

Different strokes

Hi Guys (Girls,too),

First, I did not read all of these posts, but promise to. I do not drink but after reading a few, I am re-considering. Many years I worked before re-turning to school. I appreciate different ways of visualizing what we, already, think is what's going-on.

In a single conductor (wire) there are many complex things going-on. Not just charges flying-down and rounding the turn, and returning (like a Nascar race). There is no doubt a complex system of collisions (electrons?), and subsequent waves within a single wire. Visualizing these is difficult; proving this another matter.

When considering a lighting bolt, I tried to imagine all the particles going back-and-forth, back-and-forth, countless times setting-up the not-visible circuit before the discharge occurs (at lightning speed). Some lucky people have stated that seconds before the lightning bolt, they felt their hair stand-up. So, in my simple way, I'm working-on the idea that some circulation is set-up within a single wire; conductor; lightning bolt; arc.

It's extremely difficult to change the way we view things, or take something easy and make it difficult (any lawyers here), but stepping-back and taking another look is a healthy approach. The "bird-on-the-wire" or helicopter servicing the HV lines fascinates me. I'm just glad that I learn new things everyday.

Thank you,
 
crossman said:
My point is, if the generator sends an electron out to the negative terminal, this causes an absence of an electron at the positive terminal, and this is absolutely due to the capacitance between the terminals.
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You are putting far too much stock into the term "capacitance". A capacitor is simply a subset to the same mechanics that are causing electron transfer. While all of this is very closely interrelated, it does not mean that everything with a similar electron transfer constitutes a capacitor.

I have to be careful at this point, because if I don't crack a text book myself pretty soon, I will probably mis-state something, and will "get my hat handed to me" in a hurry. :grin: You are heading in the right direction with your research on electric fields, but you've jumped a few pages too far forward and are applying too much of this as though it was capacitance.

The mechanics causing the electron transfer are the same (at least similar, without cracking a text book) to how a capacitor works, but it is not a capacitor in-and-of-itself. The reason why I made this distinction previously is because some people (you included) that were taking use of the word "capacitor" as meaning that a completed circuit existed via capacitance of the line.
 
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Thank you for the thoughts, Rick. Honestly, I have been vacilating back and forth on the issue. Here are more random thoughts:

Rub a glass rod with wool and some of the electrons in the wool will migrate onto the glass. This is due to some "stronger electrical attraction" of the glass compared to the wool. The we can seperate the glass rod from the wool leaving a negative charge on the glass rod and a positive charge on the wool. I don't see this as capacitance (although once seperated, I suppose it could be argued).

In the above scenario, the glass rod does indeed have excess electrons on it. This creates an electrostatic field which can interact with other charges. These excess electrons can even be made to flow to other objects which are more positive than the glass rod. Of course, we are speaking of static electricity. Friction and molecular/atomic/electron forces between two materials is typically the cause of this static electricity.

With the glass rod, we have the glass molecules/atoms with just as many protons as electrons, but we also have the extra electrons from the wool. These electrons are not "attached" to the atom through normal atomic means.

Now compare that to a generator creating emf. Electron movement is created through induction. This is very much different than the creation of excess electrons on the glass rod above. The generator has two terminals. Perhaps the inductive forces in the generator pull some of the electrons from the positive terminal into the windings and then push them over to the negative terminal. But I don't see this as really creating excess electrons in the same sense as we did with the glass rod. The two charges in the generator are more closely bound together, to the extent that if the generator is turned off, the charges will rush to equalize. Only the EMF of the generator is keeping them apart.

This just seems like two different things here.

Now, a nice experiment would be to have some wires attached to the negative and positive terminals of the generator, turn it on, then remove the wires. Perhaps we can "capture" some excess charge in the wires. We could remove the wires from the vicinity of the generator and have some excess electrons. I need to think more on this.

In all, I am still convinced that capacitance can be thought of as completing the circuit with the powerline and helicopter. I just don't see a generator creating excess charges which are then free to flow all over the place without "complete" circuits.

But who knows? Rick, you started this whole thing, so I am looking at you for guidance through the muddied waters.;)
 
crossman said:
...In all, I am still convinced that capacitance can be thought of as completing the circuit with the powerline and helicopter...
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I think the power line sees helicopter more as an electron reservoir.
 
Because of the ultra-high voltage, there will be a massive electric field around the power line radiating outward. A charged particle (aka electron) immersed in an electric field will have a force acting on the particle: F = Eq. Because these charged particles are within a conductor, if there is a force on them, they are free to move from that force. This will result in a bunching up of charge on one side of the helicopter. When the electric field reverses for the second half cycle, the charge will bunch up on the other side of the helicopter. Because we are close enough to the power line for arcing to occur, a lot of this charge movement includes the charge transfer to and from the line.

Going back to one of your previous postings, where you said there was no excess charge. Even if a solid body did not have a net excess charge, if you moved all of the charge to one side of the body, that would constitute excess charge for that local area. There are more electrons in that area than would otherwise normally want to be there. I don't know how (or if) this pertains to the discussion, but I thought I would throw it out there for thought.
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Oh, after giving this more thought, this excess charge concept is pertinent to Smart_$'s new posting (and my response below) regarding the helicopter being a reservoir.
 
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Smart $ said:
I think the power line sees helicopter more as an electron reservoir.
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I didn't see your posting while I was typing my previous post, but this is exactly what is happening. That's what I was trying to lead to when I mentioned the rotating pipe analogy a few pages back.
 
I apologize if this is nothing new here, but I just came across this at another forum and thought it was rather apropos for this discussion.

skak.gif
 
Rick and Smart$, thanks for continuing the discussion. I have some commentary on what you wrote, but please allow me to provide this on Monday when I have a faster i-net connection and more time.

P.S. It is still capacitance.:grin:
 
Smart $ said:
I think the power line sees helicopter more as an electron reservoir.
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Smart, such a device is called a CAPACITOR--in this case the common plate of a multisection capacitor; the other plates comprise the phase wires, the earth, and any other cables strung in parallel.

If someone can provide a solid reference proving that this phenomenon can be explained as anything other than capacitive current I might believe it. As it is, I am hearing only unsupported theories. I promise not to dodge the issue by attacking the messenger.

Not only do we have capacitance to earth, but also between phase wires, and capacitive currents flow through these capacitances at all times. The addition of a helicopter and a Faraday suit merely adds a lump to the distributed capacitance of that line.

Now, can anyone deny that these currents exist?
 
One step forward, two steps back. :confused:

If it is more comfortable to you, then fine, call it a capacitor. However, the mistake you are making is considering this to be a path to ground. Do the analysis. How much capacitance between the line to ground, versus how much capacitance between the helicopter to ground? If the capacitance of the helicopter is not significantly greater than the line to ground, then you cannot explain the arcing.

This whole issue revolves around your assertion that the helicopter somehow provides a greater path to ground than the line does on its own. If the capacitance between the line to ground was even remotely equal to your assertion regarding the helicopter to ground, then the power line would bleed so much power that it would be of little use as a transmission medium.

Do an E-field analysis. how strong is the E-field at the ground for the wire, versus the helicopter? You will find that the E-field is rather low, and this is the reason why these lines are strung as high off the ground as they are. As I already noted, the helicopter is hovering above the height of the line.
 
I'm with Rattus on this one. The capacitance is not only to ground, but to other phase wires, the towers themselves, the multi-bonded neutral, and any other wires in the vicinity.

This capacitance exists along the entire length of the line, and certainly the poco allows for this fact in the operation and construction of the lines. The helicopter, as a conductive body, serves to intensify the capacitance in the area around the helicopter. The charge which is normally spread out is concentrated to the helicopter.

There is a difference between:

current flowing in a circuit due to an EMF

and

static electricity from excess electrons

Think about it: At a given point in time, the electrons in the negative wire are trying to go to the positive side of the source. For a given length of wire, the most positive thing for those electrons to flow to is the next given length of wire in series down the line. There are no "excess electrons" which can jump to the helicopter. An electron flowing out of the negative side of the source that jumps to the helicopter must be accounted for by an electron which flows into the positive side of the source. This will absolutely be accounted for by capacitance to ground, other phase wires, and whatever else is in the vicinity. For an electron to leave the generator, there has to be an electron entering the generator.

Rick, I have read the texts, I have done alot of thinking, and have written my thoughts and reasoning here. Instead of just saying Rattus and I are wrong, please give a mechanism and reasoning of how this can happen instead of just saying we are wrong.
 
The way it is:

The way it is:

Please open the attached document for a diagram and explanation of the xmission line debate.
 
I thought we were making progress on this, but all of a sudden, it fell into the crapper and the two of you are reverting back to the terms you are more comfortable with. Crossman was headed down the right path with his research, but the instant the ?cap-word? was brought back into the discussion, he abandoned everything he was learning, threw up his arms in surrender, and reverted back to his baser thoughts.

I have never said there wasn?t capacitance between the lines and between the lines and ground; but what I have been trying to steer you away from is the thought that these capacitances are of any significance.

Capacitance is a function of shape and of distance. The ?near-infinite? length of the wire makes the power line a far better shape for a capacitor than the ?ball-shape? of a helicopter. The distance between the wire and any other conductor is less than the distance between the helicopter and any of these same conductors. There is capacitance, but it is still trivial in comparison to the rest of the mechanics. The capacitance of the helicopter to any conductor is less than the capacitance that was already present in the line system.

These transmission systems are designed to make capacitance trivial by their height and separation. The addition of an even less efficient capacitor is not going to change the electrical properties of the power line by an appreciable amount.

If capacitance was the primary transfer medium, the lines would be arcing amongst themselves and/or ground before the helicopter came into the picture. The fallacy of your argument is the presumption that the helicopter creates a better capacitive coupling than the lines do by themselves. It doesn?t take much analysis to realize that the helicopter makes for a very poor capacitive plate, and its distance is greater than the existing distances.

I told you at the beginning that I was not interested in creating a mathematically defensible proof of this because it would take more time than I am willing to expend. I have done some quick scans, and it would take a review of 5 chapters of my freshman physics text book to ensure that I had everything covered. I didn?t delve into this deep enough to extract the complex math required for a proof, but I did dig deep enough to know that I have not made any mistakes. What is interesting, is that there are no Electrical Engineers that are stepping forward to contest what I am stating, and the comments made by a utility engineer on this forum seem to have gone unnoticed. I have great respect for Crossman because he stopped to do more research before presenting his information. Please don?t stop just because an easier answer seems to be closer at hand.
 
Rick Christopherson said:
I thought we were making progress on this, but all of a sudden, it fell into the crapper and the two of you are reverting back to the terms you are more comfortable with. Crossman was headed down the right path with his research, but the instant the ?cap-word? was brought back into the discussion, he abandoned everything he was learning, threw up his arms in surrender, and reverted back to his baser thoughts.
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Your professionalism is outstanding. :roll:
 
Rick,

Your arrogance is overwhelming! You admit you don't remember your Physics, yet you set yourself up as an expert and demean those who disagree with you. And, you rudely reject references which conflict with your position. You obviously don't remember your AC Circuits either. Your arguments are vague, and your conclusions are arbitrary. You appear to be incapable of understanding my arguments, or maybe you just don't try.

It is obvious that continuing this discussion is futile, so I am withdrawing until someone comes up with something of value.
 
Rick Christopherson said:
The capacitance of the helicopter to any conductor is less than the capacitance that was already present in the line system.
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You mention that the helicopter is further away from the other lines and ground than the distance between the lines. That is true. But my Physics texts show that the electrostatic field curves around the negative and positive conductive bodies (in this case, the wires) in a manner somewhat similar to magnetic flux. The electrostatic field doesn't just go directly from conductor to conductor. It also goes out in the opposite direction and then curves back toward the other conductor. So a helicopter on the outside of the wire still is in the electrostatic field of the capacitance between the wires. With that being the case, the helicopter would certainly change (increase) the capacitance of the system in that immediate vicinity.

Rick Christopherson said:
These transmission systems are designed to make capacitance trivial by their height and separation. The addition of an even less efficient capacitor is not going to change the electrical properties of the power line by an appreciable amount.
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I don't think it is going to be less efficient. It is going to increase the capacitance in that vicinity.

Rick Christopherson said:
If capacitance was the primary transfer medium, the lines would be arcing amongst themselves and/or ground before the helicopter came into the picture.
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I don't see how you can say that. The capacitance of the line is low enough to not arc amongst themselves. When the chopper enters the electrostatic field of the capacitance between the highlines, the electrostatic field is concentrated by the helicopter. As Rattus said, essentially the helicopter becomes an addition to the capacitive plate of whatever phas it is closest to.

Think about it like this. And to simplify, let's only consider two phases) You have the two conductors and we are looking at the capacitance between A phase and B phase. We can narrow it down and only consider, say, a 30 foot section of the transmission lines and the capacitance between the two wires over that 30 foot section. We will assume the chopper is near A phase. Pick a given instant where A phase is negative and B phase is positive. As the chopper nears the A phase wire, the electrostatic field from the capacitance of A and B will move some of the electrons in the chopper away from the A phase. The A phase negative field pushes the electrons in the chopper away from the A phase and following the electrostatic field in the chopper. At the same time, the positive side of the field from B phase which curves in space to completely surround the negative A phase conductor will also influence the electrons in the chopper to move away from the A phase.

Now, assuming the chopper is not between the conductors and the chopper's center of mass is slightly above the conductors, then some of the electrons in the chopper will move to the top of the chopper following the electrostatic field. Essentially, the chopper becomes an addition to the surface area of A phase which is one of the conductive bodies which constitute the capacitance.

And I am quite certain that increasing the surfave area of the capacitor causes an increase in capacitance. And if you think about it, the chopper SIGNIFICANTLY increases the surface area of A phase in the immediate vicinity of the chopper.

Rick Christopherson said:
I told you at the beginning that I was not interested in creating a mathematically defensible proof of this because it would take more time than I am willing to expend. I have great respect for Crossman because he stopped to do more research before presenting his information. Please don?t stop just because an easier answer seems to be closer at hand.
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I don't need some complex mathamatical account, I an just requesting a theory which can account for the electron movement in the scenario. To me, capacitance seems to do that.

Rick Christopherson said:
I have great respect for Crossman because he stopped to do more research before presenting his information. Please don?t stop just because an easier answer seems to be closer at hand.
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I appreciate that. I am still interested and will consider alternate theories when they are presented.
 
Rick Christopherson said:
I told you at the beginning that I was not interested in creating a mathematically defensible proof of this because it would take more time than I am willing to expend.
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How do you expect to convince anyone of your "theory" unless you can show the proof? :roll: It seems to me that if you are on the verge of such an earth shattering discovery that you should be more than willing to put the time into a proof.

At the very least, if you have such a proof, you can post a link to it or make a word document.
 
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