AWG wire size
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ragbagflyer
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If I recall skin effect only applied to AC so Twotter would be bang on.
But what is amazing is that a simple question that had a simple answer brought about a lot of information that may or may not be correct, posted by people who may or may not know what they are talking about, and at the end of the day the depth covered is only practical to D.A.D's and has no realistic value.
But what is amazing is that a simple question that had a simple answer brought about a lot of information that may or may not be correct, posted by people who may or may not know what they are talking about, and at the end of the day the depth covered is only practical to D.A.D's and has no realistic value.
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Nightshiftzombie
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Behold the power of the Internet!But what is amazing is that a simple question that had a simple answer brought about a lot of information that may or may not be correct, posted by people who may or may not know what they are talking about
"Thats what the Internet is for stupid. Slandering others anonymously."
Twotter, I see now. Your knickers are in a twist over my statement;
First of all, stranded wire isn't made up of a bunch of little insulated solid wires. The strands make contact with one another. Furthermore, like I mentioned before they are "squashed" together when they are formed, so much more contact is made than just the tangent surfaces.
So at worst, stranded wire reacts like solid wire with tiny imperfections in it. It certainly acts more as solid wire than multiple strands that individually carry current. The actual current flow through the strands and their interaction is quite complex and beyond the scope of this discussion.
http://en.wikipedia.org/wiki/Skin_effect
Wikipedia (for what its worth) states that skin effect causes current to flow at the surface of the wire. Even all the way to 10 KHz the skin depth is 0.66 mm. At 60 Hz its 8.57 mm. Extrapolating we can see that at 400 Hz it would still be quite deep.
If we conservatively assume that the skin effect depth at 400 Hz is 8 mm, and we accept that the skin of a tubular wire goes 360 degrees around, then the current will penetrate approximately 16 mm of the wire which equates to a wire larger than "0000" (about 12 mm).
Another Wikipedia entry (again for what it’s worth) discusses skin effect on audio cables which normally carry frequencies up to 20Khz.
http://en.wikipedia.org/wiki/Speaker_wire
From the article,
“Listener bias is helped in no small part by the large number of wire manufacturers making unscientific claims about their own product. Many manufacturers catering to audiophiles as well as those available in department stores make unmeasurable claims about wire being open, dynamic, or smooth. To justify the claims, many rely on less understood electrical properties such as skin effect, characteristic impedance of the cable or resonance (these have no measurable effect at audio frequencies but are important at radio frequencies)"
So does than mean skin effect at 400 Hz is irrelevant? Not when you're talking about huge currents in industrial applications with wires larger than your d*ck. But on airplanes...not so much. One might say "negligible".
By the way, what's a D.A.D.?
That statement stands for aircraft power distribution systems that I know of including those that are 400 Hz AC.For the purposes of determining current handling, the difference between solid and stranded wire is negligible.
First of all, stranded wire isn't made up of a bunch of little insulated solid wires. The strands make contact with one another. Furthermore, like I mentioned before they are "squashed" together when they are formed, so much more contact is made than just the tangent surfaces.
So at worst, stranded wire reacts like solid wire with tiny imperfections in it. It certainly acts more as solid wire than multiple strands that individually carry current. The actual current flow through the strands and their interaction is quite complex and beyond the scope of this discussion.
http://en.wikipedia.org/wiki/Skin_effect
Wikipedia (for what its worth) states that skin effect causes current to flow at the surface of the wire. Even all the way to 10 KHz the skin depth is 0.66 mm. At 60 Hz its 8.57 mm. Extrapolating we can see that at 400 Hz it would still be quite deep.
If we conservatively assume that the skin effect depth at 400 Hz is 8 mm, and we accept that the skin of a tubular wire goes 360 degrees around, then the current will penetrate approximately 16 mm of the wire which equates to a wire larger than "0000" (about 12 mm).
Another Wikipedia entry (again for what it’s worth) discusses skin effect on audio cables which normally carry frequencies up to 20Khz.
http://en.wikipedia.org/wiki/Speaker_wire
From the article,
“Listener bias is helped in no small part by the large number of wire manufacturers making unscientific claims about their own product. Many manufacturers catering to audiophiles as well as those available in department stores make unmeasurable claims about wire being open, dynamic, or smooth. To justify the claims, many rely on less understood electrical properties such as skin effect, characteristic impedance of the cable or resonance (these have no measurable effect at audio frequencies but are important at radio frequencies)"
So does than mean skin effect at 400 Hz is irrelevant? Not when you're talking about huge currents in industrial applications with wires larger than your d*ck. But on airplanes...not so much. One might say "negligible".
Thats 100% true. These topics have a tendancy to expand beyond the original scope as people flex their "know-it-allness". And yes, it may all be bullshit. The silver lining here is that nobody is forcing you to chose. Make up your own mind.But what is amazing is that a simple question that had a simple answer brought about a lot of information that may or may not be correct, posted by people who may or may not know what they are talking about, and at the end of the day the depth covered is only practical to D.A.D's and has no realistic value.
By the way, what's a D.A.D.?
CID, your normal crap has started again.. First off I don't need a no mind like you to try to teach me anything about electricity. I also don't need a lecture.. I'm sure I was working with electricity when you were still thinking that it was only for pissing. End of story with you, go away.
Simplified version:
http://www.rowand.net/Shop/Tech/WireCapacityChart.htm
Simplified version:
http://www.rowand.net/Shop/Tech/WireCapacityChart.htm
Stranded vs. Solid Wire
This one is a bit of a mind-boggler, but it's important. When electricity flows through a wire, it mostly flows on the surface of the wire, not through the middle. This effect is more pronounced on high frequency AC than it is on DC or low frequency AC. This means that a "wire" of a given size that made up of many smaller strands can carry more power than a solid wire - simply because the stranded wire has more surface area. This is one reason why battery cables in your car and welding cables are made up of many very fine strands of smaller wire - it allows them to safely carry more power with less of that power being dissipated as heat. However, this "skin" effect is not as pronounced in a typical 12V DC automotive application, and the wire and cable used there is stranded for flexibility reasons.
When looking at a chart or description of wire capacity, take note of whether it is referring to stranded or solid wire - some charts may not specify but instead assume a default based on the typical wiring used in a given application. For example, almost all automotive wiring is stranded while almost all home wiring is solid. For most applications, flexibility or the lack thereof will be more important, but for very high frequency AC applications, stranded wire might be a requirement.
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Cat Driver
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Twotter,
I took great care in avoiding confrontation while discussing the subject matter. You are the one who is being hostile.
Skin effect is a property of wire in AC circuits not DC circuits. The writer of the link you provided is a little off on that fact.
Furthermore, the real reason jumper cables and welding cables are made of very fine strands is so they will be flexible and resistant to breakage. The writer of your link agrees.
It appears to me Twotter that you are just looking for a fight. Please leave me out of it.
gli77,
My brain fart. I should have recognized the DAD term. The dots threw me off. Having said that, I think a DAD is a "Design Approval Designee". Like a DAR but typically associated with a manufacturer.
Cheers
I took great care in avoiding confrontation while discussing the subject matter. You are the one who is being hostile.
Skin effect is a property of wire in AC circuits not DC circuits. The writer of the link you provided is a little off on that fact.
Furthermore, the real reason jumper cables and welding cables are made of very fine strands is so they will be flexible and resistant to breakage. The writer of your link agrees.
It appears to me Twotter that you are just looking for a fight. Please leave me out of it.
gli77,
My brain fart. I should have recognized the DAD term. The dots threw me off. Having said that, I think a DAD is a "Design Approval Designee". Like a DAR but typically associated with a manufacturer.
Cheers
Again we go on with the half truths, smoke and mirrors etc. Remember the old saying "If you can't dazzle them with brains, baffle them with bullshit." Well CID is the poster boy for that saying.
"This means that a "wire" of a given size that made up of many smaller strands can carry more power than a solid wire - simply because the stranded wire has more surface area. This is one reason why battery cables in your car and welding cables are made up of many very fine strands of smaller wire - it allows them to safely carry more power with less of that power being dissipated as heat. However, this "skin" effect is not as pronounced in a typical 12V DC automotive application, and the wire and cable used there is stranded for flexibility reasons. "
I'm not sure how much more clarification is required but my experience with this fellow is such that I would be wasting my time trying to show what is correct. I continue to post here on this subject to show people the truth and not allow them to be led down the garden path of bullshit.
Have a good day all.
This is from the article I posted:Furthermore, the real reason jumper cables and welding cables are made of very fine strands is so they will be flexible and resistant to breakage. The writer of your link agrees.
"This means that a "wire" of a given size that made up of many smaller strands can carry more power than a solid wire - simply because the stranded wire has more surface area. This is one reason why battery cables in your car and welding cables are made up of many very fine strands of smaller wire - it allows them to safely carry more power with less of that power being dissipated as heat. However, this "skin" effect is not as pronounced in a typical 12V DC automotive application, and the wire and cable used there is stranded for flexibility reasons. "
I'm not sure how much more clarification is required but my experience with this fellow is such that I would be wasting my time trying to show what is correct. I continue to post here on this subject to show people the truth and not allow them to be led down the garden path of bullshit.
Have a good day all.
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ragbagflyer
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ragbagflyer
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Twotter,
I'm just trying to point out that the source you quoted is wrong. I read what the guy wrote and checked out his entire website. It's an entertaining read but technically speaking it's full of inaccuracies.
The fellow acknowledges that he's not an authoritative source and even invites readers to correct him.
The simple truth is that skin effect is an AC phenomenon. The formula for determining the skin effect depth divides the various formula elements by the square root of the frequency. Since the frequency of DC is zero, the resultant depth is infinite (divide by zero).
I’m sure the fellow means well and is sincere but he also states;
He also has a wire capacity chart (based on gauge) that is quite dangerous if anyone choses to take it seriously. He suggests that circuit voltage has some kind of determinate effect on wire guage selection. He says that you can run 150 Amps through an AWG 10 wire at 12 VDC. That's just plain wrong.
A word to the wise. Don't wire your airplane using random unauthoritative information you find on the internet. That includes the stuff discussed here on this thread.
When in doubt, check it out!
By the way, I don't understand what you mean by your last post. Are you saying that the chap doesn't state that the stranded wire in jumper cables is mainly for flexibility?
I'm just trying to point out that the source you quoted is wrong. I read what the guy wrote and checked out his entire website. It's an entertaining read but technically speaking it's full of inaccuracies.
The fellow acknowledges that he's not an authoritative source and even invites readers to correct him.
The simple truth is that skin effect is an AC phenomenon. The formula for determining the skin effect depth divides the various formula elements by the square root of the frequency. Since the frequency of DC is zero, the resultant depth is infinite (divide by zero).
I’m sure the fellow means well and is sincere but he also states;
I think President George W. Bush is doing a pretty good job. I voted for him, I think he's doing a darned good job of running the country (a heck of a lot better than Slick Willie), and I support what he is doing in Iraq.
He also has a wire capacity chart (based on gauge) that is quite dangerous if anyone choses to take it seriously. He suggests that circuit voltage has some kind of determinate effect on wire guage selection. He says that you can run 150 Amps through an AWG 10 wire at 12 VDC. That's just plain wrong.
A word to the wise. Don't wire your airplane using random unauthoritative information you find on the internet. That includes the stuff discussed here on this thread.
When in doubt, check it out!
By the way, I don't understand what you mean by your last post. Are you saying that the chap doesn't state that the stranded wire in jumper cables is mainly for flexibility?
However, this "skin" effect is not as pronounced in a typical 12V DC automotive application, and the wire and cable used there is stranded for flexibility reasons.
Ok, you want a source, I was brought up as an electrician, both my father and my uncle did it all their lives doing heavy industrial construction. I of course disappointed them by getting into aviation.
Between them they ony have just over 110 years since being TQ'd. Not sure about you, but I'd say they know what they are talking about when it comes to this. Unlike other people on here, I do not have unlimited time to cut and paste crap, I go by what I know. If you all want to go along and believe what you want, go ahead, but I will believe the guys who have done this all their lives who have worked with everything from 5Vdc to 500KVac..
Between them they ony have just over 110 years since being TQ'd. Not sure about you, but I'd say they know what they are talking about when it comes to this. Unlike other people on here, I do not have unlimited time to cut and paste crap, I go by what I know. If you all want to go along and believe what you want, go ahead, but I will believe the guys who have done this all their lives who have worked with everything from 5Vdc to 500KVac..
500KVac! Wow. It sounds like your family is in the HEAVY INDUSTRIAL electricity game. You certainly won't find that sort of voltage in aircraft. At least none I'm aware of.Twotter
If you all want to go along and believe what you want, go ahead, but I will believe the guys who have done this all their lives who have worked with everything from 5Vdc to 500KVac..
The odd thing is that I seem to remember stating;
I'm still at a loss to figure out exactly what I have stated that is wrong in your opinion and this new information just seems to re-enforce what I've stated. Help me out here.CID
So does than mean skin effect at 400 Hz is irrelevant? Not when you're talking about huge currents in industrial applications with wires larger than your d*ck. But on airplanes...not so much. One might say "negligible".
Actually, before you reply, you can consider 400 Hz and 60 Hz very similar when it comes to determining skin effect. The difference is (again) "negligible".
First off, remember that they have experience on a variety of systems:
From a PM from CID:
More from the same PM:
BBFN
Yes they did heavy industrial, but that does not always involve high voltage, as you can see from my statement. As usual you are just trying to pick and choose which part of what I say to nitpick against.If you all want to go along and believe what you want, go ahead, but I will believe the guys who have done this all their lives who have worked with everything from 5Vdc to 500KVac..
From a PM from CID:
It seems to me that you were the one who came into this discussion countering what I had to say, since then I've just been proving my point.Twotter, why are you targeting me in this wire discussion? Its so obvious you came out swinging and in the end all you're doing is embarassing yourself.
More from the same PM:
I would say that it is usually you who comes into a post and disrupts it with your half truths, your manipulation of words, your first post on this subject contained:You and I have history on this board and I seem to usually be on the receiving end of your attempts to undermine my credibility. Like before, I'm not going to just sit and take it
Later you said:There is very little difference between stranded and solid wires with respect to their current carrying capabilities unless you are using it in a high frequency application. They you have to worry about "skin effect".
You choose your words carefully to manipulate a conversation, you contradict yourself, all to ensure you can discredit someone else. I honestly thought you had been thrown off this board for your previous actions against myself and others. If you would like more examples I will post more later for you.So does than mean skin effect at 400 Hz is irrelevant? Not when you're talking about huge currents in industrial applications with wires larger than your d*ck. But on airplanes...not so much. One might say "negligible".
BBFN
I'm at a loss twotter. I made what I thought were extremely fair attempts at working out our differences that lead to these conflicts.
I did the responsible thing by taking the personal scuffle offline in a PM but you dragged it right back into the public arena. What exactly does that say about you? I'll let other readers make up their own minds.
I haven't contradicted myself in this discusion. The two statements you are comparing don't contradict each other. FYI 400 Hz is not "high frequency". In fact it is a very low frequency.
I find it odd however that you didn't bother to post the entire PM. Just enough to "manipulate" the conversation.
As for being "thrown off" I stopped posting here because I was just plain tired of the harrassment from you and a few of your cronies. I was also tired of the lack of moderation and integrity in some moderators.
I thought I would start contributing again but I see this site is the same as ever. I'll just continue to be a target for predators like you twotter and the moderators won't do a damn thing about it as it escalates out of control.
I'll stop there as I really don't want to sink any closer to your level.
Cheers
I did the responsible thing by taking the personal scuffle offline in a PM but you dragged it right back into the public arena. What exactly does that say about you? I'll let other readers make up their own minds.
I haven't contradicted myself in this discusion. The two statements you are comparing don't contradict each other. FYI 400 Hz is not "high frequency". In fact it is a very low frequency.
I find it odd however that you didn't bother to post the entire PM. Just enough to "manipulate" the conversation.
As for being "thrown off" I stopped posting here because I was just plain tired of the harrassment from you and a few of your cronies. I was also tired of the lack of moderation and integrity in some moderators.
I thought I would start contributing again but I see this site is the same as ever. I'll just continue to be a target for predators like you twotter and the moderators won't do a damn thing about it as it escalates out of control.
I'll stop there as I really don't want to sink any closer to your level.
Cheers
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ragbagflyer
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Twotter, what do you mean be "brought up as an electrician"? Did you go to four years of trade school? Having electricians in the family doesn't mean a hell of a lot when you're debating the specifics of an electrical phenomenon. I'm sure you know more about electricity then me but on this topic I'm pretty sure you're way off base. I don't think you're convincing anybody else here either.
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G.N. Thompson
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