Cable directionality

Audioengr--- well, I didn't get to talk to the EE's here at work today, duty called. However, I will. I still don't understand this so I will get one of my troopers to explain it up close and personal. With house wiring, the neutrals are connected straight to the buss bar in the breaker panel and and connected to earth ground. I still don't understand your previous analogy of the battery and bulb since DC does flow in one direction period. And you do have positive and negative on DC. There is no such thing as positive and negative on AC which it would have to be. The return would be negative. As I said before, you have the positive half cycle and then the negative half cycle that "Flows" the opposite direction on the same wire. In an Air Conditioning unit you have a step down transformer usually 120/230 to 24 volts. On the output of the secondary, one side is tied directly to earth ground and also serves as the common for the wiring activating all the small 24VAC coils on relays. The other runs to the other side of the coils. I still can't believe that you will have an opposite polarity running through the unit chassis. I know I can't measure it because I have tried. Why would it go back when the path of least resistance is to earth and not through the resistance in the wire? AC is AC is AC. It doesn't matter if its in a house, an Air Conditioner or a signal carrying cable. I suppose coaxial cable, with a single conductor, alternates with the shield and with the shield connected to earth ground and there is no second wire.
By the way, I don't need to be convinced that you are an EE with whatever experience. To me, this is research and I will find a definitive answer that satisfies my curosity. Call me hard headed. And I defer back to my final statement in the last post. Anyway, this post was about cables being directional and not a dialog in electrical theory. They may never let me post again! Anyway, I am convinced that cables being directional is BS and ALL the EE's I work with are in agreement with that.

Audioengr---Well, I just had one of the EE's stop by and we had a nice little chat. It convinced me of basically what you are saying and actually created a few more questions. As stated previously in my post, I will officially acknowledge that you were essentially correct. I think terminology got in the way a little but I have to say this has been a very enlightning experience and I do appreciate your patience with a ME. He also talked about DC coinciding with AC in a cable which I will have to research now. Bleed I believe was the term he used. He left me a book to read (which I will do) and a bag of terms about lifting ground, floating above ground, etc. He also blew right over my head talking of using DC on signal cables to make the AC behave itself. This will require more research.

Bigtee wrote: "As I said before, you have the positive half cycle and then the negative half cycle that "Flows" the opposite direction on the same wire."

Correct, the current alternately flows in what I like to call the "forward" wire, but the inverse of that current also flows simultaneously in the second wire, which I call the "return" wire. In most AC power systems, this is NOT the ground wire, because this would violate electrical code, regardless of whether the circuit is single-phase or three phase.

Bigtee wrote: "On the output of the secondary, one side is tied directly to earth ground and also serves as the common for the wiring activating all the small 24VAC coils on relays. The other runs to the other side of the coils."

If this is the case, then for these internal circuits, the ground is used as a return path for the current. It would be difficult to measure any voltage drop across a grounded chassis, because the impedance is so low.

I actually worked as an industrial electrician apprentice while I was going to college 27 years ago, so I have some experience with electrical code, 3-phase, contactors and transformers etc..

Audioengr-
I appreciate your information and trust me, I will get a handle on the "Why." I think we have been engineers for about the same length of time. I graduated a ME in 1975. I didn't learn much about electricity in school and have been in industrial design for a long time. We have electrical guys in our group that handle the biggest portion of the electrical work, naturally. I do design air conditioning control systems working closely with general contractors. I have always understood the codes and the wiring requirements but never researched the "Why." I guess now is a good time to start. I have been playing with audio equipment since I was about 12. Never had any electronic training but understand how it works somewhat. I have built some really decent sounding interconnects but don't have a clue to why they turn out as they do. I have played around with the metals and the shield schemes. I have found, keep them as short as possible and for whatever reason, I find solid wire better than stranded. I have never been able to detect any direction inconsistancies in the wire.

Here are some more tips for you, since I design wires for my company:

1) interconnects should be low capacitance - this means spiraled pairs of small gauge wire that are spaced-away form each other. Use Teflon or air-filled dielectrics to separate and insulate them.

2) Speaker cables should be low inductance and low resistance. To get low inductance, you need coupling, so make many twisted-pairs of 20-24 gauge wire and then connect then at the ends to for a single circuit.