Re-purpose, recycle, reuse---'MAKE'-do not throw it all away.

[paul1598419]

Yes, eddy currents are setup inside conductors that have AC current running through them. The changing electric fields cause these to cancel out currents toward the center of the conductors and tend to be proportional to the frequency of the alternating current. This causes the skin effect. You can look at stranded wire as being parallel paths for the current to flow, so the more strands the lower the total impedance of the stranded wire. That is the main reason that stranded wire is better for AC currents.

Since you like links, here's one that backs this up. Look toward the end of the article when the words "stranded wire" are highlighted. https://www.arrow.com/en/research-and-events/articles/the-skinny-on-the-skin-effect

Yesterday my daughter and her family came by to visit me. Got to see my granddaughter and she is growing quickly. Don't come here to argue about the differences between AC and DC circuits. Certainly don't need these kinds of confrontations. I already know everything brought up here, so I'm not going to get into this again.

 

[Cyparagon]

You can look at stranded wire as being parallel paths for the current to flow

They're not isolated. It's all the same conductor, but with holes in it.

stranded wire is better for AC currents.

Once again, DOESN'T APPLY in 60Hz applications listed in this thread. No one is putting 4MHz through an extension cord. And stranding the wire doesn't do shit anyway, because the strands aren't isolated. You clearly haven't even read the wikipedia links.

https://www.arrow.com/en/research-and-events/articles/the-skinny-on-the-skin-effect

You refuse to read my links, but I've read yours. Not only is that one point wrong, you've misunderstood the rest of the article completely.

You're using this link as a drunk man uses a lamp post. For support rather than illumination. Note your link here is ONE article by ONE author, Laura Hughes, who is the "Manager of Application Marketing " Compare that with the thousands of authors on wikipedia. But that sounds like Paul. Listen to one voice (his own) and ignore the rest of the world (except laura, who probably just misspoke).

Power lines are an entirely different animal. They look tiny when they're dozens of feet in the air, but I assure you they're not. Since you won't follow links, I'll hotlink a photo so you don't have a choice.

Yes, even here the skin effect begins to be a problem. But only slightly, as the center conductors are often made of steel, which serve as support for the cable rather than carry the current. Again, stranding the conductor does not isolate the strands.

But let's critically examine her passage "This is why stranded wire is so common in AC applications, even for relatively low frequency applications like power lines ". Is it though? Tell me Paul, how many strands are in the 14awg wire running in your house walls? What about the 12awg? What about the 10awg that has enough power to run a clothes dryer? NO?? Still one strand? How can it be? Is it even possible to find stranded house wiring, since it's SO MUCH BETTER? I doubt it. Maybe you think the regulatory agencies like NEMA, IEC, IEEE, UL, CSA, had nothing to say about the NEC being constructed without stranded wire as a residential wiring standard because they don't care about electrical efficiencies or electrical safety of houses? Can Paul really think these companies that stupid? Clearly Paul knows better. It can't be as simple as "flexibility doesn't matter as much when the wire... never moves", can it Paul?

Only at 8awg does most household wiring become stranded. But I guess there's no way you would know this, since you're clearly so shit with electrics, but bending 8awg solid wire through and around electrical boxes and in tight spaces is a bit of a pain in the ass. Stranding helps with this greatly, but AGAIN it does fuck-all for the skin effect. AGAIN, skin depth is way deeper than the conductor.

Even your favorite author, Laura, had this to say in her passage that YOU linked, "At 60Hz in copper wire, the skin depth is 8.5mm. " That's WAY bigger than any extension cord conductor. It just doesn't apply here. Has the repetition helped? I somehow doubt it.

Is it possible you didn't even read your OWN link?

Yesterday my daughter and her family came by to visit me... Certainly don't need these kinds of confrontations.

Poor, poor Paul. Losing an argument so bad he's trying the pity route.

I'm not going to get into this again.

HA. Okay. So! Taking bets. Here's where we find out if Paul is lying.

Does he come back with an even thicker skull?

I already know everything brought up

Fixed that for you

 

[paul1598419]

I have not bought any wire except for the stranded varieties for many years now. But, only in part for the reason mentioned here. Stranded wire can actually carry current more efficiently too.

Here I said that stranded wire "can" carry current more efficiently as it does in parallel high tension lines. These are the the ones I was talking about.

That is why aluminum is used for high tension wires and because it weighs less than copper.

Here I said high tension wires.
[QUOTE="paul1598419, post: 1583301, member: 40752"
And I didn't say your cutoff for wire gauge was even 18. Stranded wire can have much larger strands than that.
[/QUOTE]
And here you can also find my inclusion of larger gauge wire
There are high tension wires that are isolated in the stranding and ARE parallel strands. These are lower impedance lines when looked at as parallel current paths.

To bash Laura Hughes' article as not to the point is what you always do here. First you call me names and conflate my points as being the same as a drunken man under a light pole. That is just nonsense as high tension lines have large isolated strands that act as parallel lines thus reducing their overall impedance. This is just like your opinions on the Ebola thread where you claimed I didn't know what I was talking about while siting your long experience wikipedea. You are simply an asshole who never even tried to see what I was talking about only defending your inference of what you thought I meant to say here. The fact is, stranded, isolated wire used for high tension lines are better conductors of AC current and you can't now admit that you took this totally out of context.

 

[Cyparagon]

I'm not going to get into this again.

And the results are in! - this is clearly a lie.

high tension lines have large isolated strands

ooooo I think we have a budge. Are you finally conceding that isolation of the strands is necessary?

Here I'm actually open to a source. Isolated by what? What is thin enough to not be seen, but weather resistant for decades and is also abrasion resistant as the strands are rubbing in the wind? What is the insulation material, and can you provide a source that shows this is STANDARD?

IF the strands are isolated, the outer strands are longer than the inner strands, since they complete revolutions around a larger radius. How is the standing wave and destructive interference dealt with at the terminations? In litz wire, strands are rotated from the inside to the outside, but as I said from the outset, you're not talking about litz wire. Hak isn't talking about litz wire. And litz wire doesn't do anything for 60Hz.

Here I said that stranded wire "can" carry current more efficiently as it does in parallel high tension lines. These are the the ones I was talking about.

You liar. No you weren't. Hak was talking about an extension cord. 60hz, 15A. No one here was talking about high voltage overhead transmission lines.

Here I said that stranded wire "can" carry current more efficiently

IF the frequency is well over several kHz (not the case for the subject Hak mentioned, nor in anything you work with)
OR IF the current is well over several hundred amps (not the case for the subject Hak mentioned, nor in anything you work with)
AND IF the strands are isolated from each other (not the case for the subject Hak mentioned, nor in any wire you buy)

So it's a bit like coming into... I dunno... a mineral supplementation thread, and telling everyone that (highly radioactive) iodine 131 can have great health benefits. When someone inexorably announces you're full of shit, you claim persecution, because you MEANT (but didn't mention until much later on) that if someone has thyroid cancer, it can be a viable treatment. THEY just aren't trying to see your point. Never mind this has nothing to do with mineral supplementation!

It's barely one step above "remember when I got those questions wrong on Jeopardy? I was being sarcastic"

Next time you're baffled by how <insert your favorite politician here> can be so blatantly wrong about something, and brush it off the next day as if nothing happened... "How can he possibly do that?" you ask those around you. Look inward.

I have not bought any wire except for the stranded varieties for many years now... Stranded wire can actually carry current more efficiently too.

See, this clearly links how you're wrong. You're wrong in thinking the stranded wire you buy can carry more current. To re-iterate, the strands are not isolated, and you're not in the dozens of kHz region

Edit: Since no one will follow my links, I'll quote them instead:
"Stranded wire might seem to reduce this effect, since the total surface area of the strands is greater than the surface area of the equivalent solid wire, but ordinary stranded wire does not reduce the skin effect because all the strands are short-circuited together and behave as a single conductor. "

"[litz wire] employs a stranded wire with individually insulated conductors (forming a bundle). Each thin conductor is less than a skin-depth, so an individual strand does not suffer an appreciable skin effect loss. The strands must be insulated from each other—otherwise all the wires in the bundle would short together, behave like a single large wire, and still have skin effect problems. Furthermore, the strands cannot occupy the same radial position in the bundle over long distances: the electromagnetic effects that cause the skin effect would still disrupt conduction."

 

[gazer101]

Well this has been an enlightening thread XD

 

[diachi]

I suppose I should have been more specific. I was actually talking about the "skin effect" that occurs with AC current. This increases with the frequency of the AC current, but one needs to use strands that are insulted with something like varnish. Of course DC currents are increased by the cross sectional area of the wire, but when the current is AC and the frequencies are higher than 50 Hz this skin effect takes over. I wouldn't characterize my statement or myself as being "full of shit", but that is par for the course from you. Since I am having to characterize my statement it is also noteworthy that this skin effect is also proportional to the square root of the resistivity of the wire material. That is why aluminum is used for high tension wires and because it weighs less than copper.

Skin effect isn't even worth considering at the frequencies used for AC power transmission. Stranded or not. Doesn't generally matter until you get to VHF. Even then it's of little concern. Isn't really an issue until you get to UHF or microwaves.

Aluminium is used because of it's decently high conductivity, low cost and low density vs copper.

Stop talking out of your ass, Paul.

 

[gazer101]

So skin effect becomes an issue in things like Tesla coils then?

 

[Cyparagon]

Yes, in a sense. Of course, in most cases it's easily overcome with the high voltages involved. Several kilovolts on the primary can punch through an extra few ohms without a second glance. It just means more waste heat and a slightly longer discharge time constant. Also, the secondary current is rather small, so the resistance doesn't matter much.

 

[hakzaw1]

thanks
more info than i needed--
i will not use it for more than one tool (like drill or sabre saw)or light.
hk