Explain the Neutral???

[mapj1]

As we move into the territory of Maxwells equations and the meaning of the dreaded Poynting vector, which in my earlier reply I struggled to avoid, has anyone noticed that the original poster has now gone to sleep?

I think, by the way, that some of this recent posting would leave most normal sparks feeling the cold too, this discussion is rapidly moving into the domain of the radio engineer or possibly the arena of a physicist with a rather sad fields and waves bent *.

I detect a few people showing off, rather than being helpful!
regards to you all,
M.

* Oh I think I can be rude about that -the description covers me too
(Masters in physics, PHD Elec eng, job involves almost anything these days)

PS
The drift velocity of the electrons is really slow. Very nearly half of the electrons are not even going the right way at any time, and their speed is mostly set by the temperature, but the delay between one in, another one out is indeed set by the speed of light moderated by the dielectric around the cable and the magnetic environment. For house cable the velocity factor will be between 60 and 80% of c in free space.
To get the same electron out the other end of a 1 metre cable of 1mm cross-section, with 1A DC, you have to wait several minutes. How you are supposed know which one it was never clear to me !

 

[ban-all-sheds]

No its not wrong; and with that, I rest mine and ****s case.

Well - I don't know what case that is. I was wrong in my analysis of Damocles' velocity stuff, which is fine - I've no hangups about being wrong.

But if I've understood correctly, you started stating your case before that diversion, and it was, essentially, that I should not have pointed out that AC means a +/- potential difference, not uniformly +, nor that the peak:rms ratio of a sine wave is 2**0.5 not 1.47, all of which was, to pick up on mapj1's point, an attempt to clarify for the OP how neutral relates to live in a normal 230V 50Hz installation. In which case, surely it was also wrong for panjandrum and Damocles to respond to my post pointing out its lack of correctness?

 

[Damocles]

Easy, you put a spot of red paint on it.

Did you ever see the one with the glas tube half filled with copper sulphate solution and half with plain water. Sat in the lab for 20 years without the two layers appreciably mixing by diffusion. Though copper atoms are very much heavier than electrons.

What kind of nutter did you think answers all these questions anyway? Don't you get tired thinking of imaginitive ways to answer the same thing again and again?

What the neutral is for is an interesting one. Much of the world thinks our three wire L, N, E system has at least one wire too many. The three phase distribution is designed to have three live lines which do not need a neutral. Neutral is only created locally at each house. The idea is that the return current from houses on different phases is combined and will cancel out. The neutral point is referenced to earth at the generator and locally to the consumer but the idea is that litlle if any current will actually travel through earth. So there is no need to actually provide a cable.

 

[Panjandrum]

In which case, surely it was also wrong for panjandrum and Damocles to respond to my post pointing out its lack of correctness?

b-a-s,
Did I really do that? Not that I would have avoided it you know, but just that if I had done it, I would have preferred to know I was
Of course, as a huge fan of a niche run-time-interpreted language, I would disagree with your most recent tag-line - subject for another thread one day perhaps when there is time.
Struggling heroically to get back to the point. Though this has been a grand chuckle so far, I am much inclined to mapj1's view. Like I said last time - it would be interesting to know if cross had found any of the responses useful!

 

[Adam_151]

So when do we find out if the cat dies?

 

[Panjandrum]

Adam_151 - congratulations.
You win my secret prize for the first one to get from that start point to the cat in the box.
There was going to be another prize for the first one to ask how long was the piece of string, but unfortunately my sense of humour fuse has just blown.

 

[Damocles]

Bas, I did think you were wrong about the velocity of electrons, but not about pointing out that AC is +- and rms. I was thinking much the same as you must have when I read the posts before yours.

Now, I am still thinking about this issue of propagation velocity being governed by the dielectric surrounding the copper conductor. I still incline to my initial reaction that since the em waves will propagate through the copper, then it is the properties of the copper which matter. Admittedly the current must have a return path so we are in fact dealing with a tansmission line where the neutral is a second piece of copper a few mm away, separated by an earthed conductor.

But to be absolutely accurate our electromagnetism lecturer did more for the paper dart design industry than anyone else and I kind of lost the thread. People would read the magazine and page by page fold and throw to indicate their joy.