OK, I'm not sure how you figure I have changed wording, outcome, and fact...? In my first post I speculated that the heat generated would be the same, in my last I basically repeated it. A couple posts between I actually gave a link to some answers to the exact same scenario in a purely resistive circuit, which has doesn't have all the extra properties of complex electronics that you are likely used to.
If you missed it, the question in the link was:
"Will 4A at 110v AC lead to a greater temperature rise than 4A at 24v DC in the same wire?"
The answers......
"No, it won't. The heating is caused by the I²R loss of the wire and not the voltage drop. The 4A AC is an RMS (Root Mean Square) value which is the energy equivalent of 4A DC."
"Also, thermal heating is a function of current only, not voltage"
"The temperature rise along the length of a cable depends only on the current it is carrying, the cross-sectional area and the material it is made of."
Or the one that backs up what I said about getting a voltage drop, but not more heat......
"However, with low voltages, it is generally more important to minimize voltage drop: if the cable carrying 4 amps has a resistance of 1 ohm per conductor, then it will be dropping 4V along the length of each conductor. So your 24V DC appliance will only be getting 16 volts! (4 volts are lost in the positive supply and another 4 volts in the negative return.) You might well want to use a thicker cable which will have less voltage drop. But a 110V AC appliance would be getting 102 volts at the far end of the same cable, which is a bit nearer the mark. Either way, the cable will be dissipating 32 watts of heat along its length." (And as I pointed out, our wire was already rated to dissipate the heat produced, the resistance of a 6' run at a safe initial operating temperature is hardly enough to trigger a cycle of thermal runaway)
I'm not sure what you're basing your "heating profile" on, but the above is some of the information that supports what I have spoken of all along. And even if you have some kind of calculated discrepancy, it's not enough to melt the wires.
All of these are perfectly in line with what I have said from the start, and nowhere along the way did I change that, not sure what you are talking about. In a purely resistive circuit, the RMS readings for AC current and voltage are basically interchangeable. In your electronics circuits with capacitors, induced voltages, pulsing, etc., those equations are an evolution of AC theory, just a little more involved. So yes, AC theory is relevant, much of it is actually interchangeable.
You are the one that said you weren't talking about your toaster, now you are hooking it up to 480vac to prove what? The numbers in your irrelevant scenario don't even make sense! When you quadruple the voltage to a resistance you quadruple the current(it wouldn't stay at 22.7) the wires will fail,... really? Isn't that kind of what I was getting at when I said you have to go way out of the ratings for it to fail? I just referenced 480v in terms of it producing the same heat in the wire at the same given amperage......Let me spell it out again though, if you hook the toaster up to 480v, it will draw 99 amps(for a very brief second), that is 47.5kw(not 11kw). Kind of like if you hook it up to 25vdc it will only draw 5.15 amps, we've already covered this, the toaster is irrelevant, your scenario doesn't even make sense, we are talking about a wire, with a given fixed amperage, at 2 different voltages.
This is copied/pasted from your example......"AWG#12 at 110VAC will carry 2400W... for 33' !!!!!!!!"
Did I miss the part where this becomes DC, bravo? Maybe you had a typo.
BTW, I think you misunderstood Cooper, I'm pretty sure he was implying that sometimes the copper tube, when sized correctly, would work better than ANY stranded wire, as in even one with more surface area."cardboard tube clad in copper would carry a better signal than ANY multi strand wire at a very specific diameter and frequency." "more skin= more transfer is just not the case".
Read his words again.
And I did not claim wiring boats as my father's profession, just that he does it. He has retired from the phone company, where he managed the projects and maintenance of the building systems and infrastructure for several large buildings in Boston. But his heart has always been in his and my brother's commercial tuna boats, just so happens he has the background to do a lot of different things(like basically build and wire the boats), but he does still renew his master electrician's license.
BTW, if you've never seen a 900 lb. bluefin Tuna be stopped dead in it's tracks by electricity coursing through the first 150' steele cable line of a harpoon dart, through another 70' of saltwater, back to a ground plate under the boat, it is a sight to behold for any electron aficionado.
As entertaining as this healthy debate has been, you have had a few days now, and still haven't given any solid evidence of your original claim. In fact, judging by the way you switched from skin effect, to thermal runaway, to grasping at straws about heating profile, to bags of horse $hit and irrelevant scenarios like quadrupling voltage and current, I'm still wondering what you based the original statement on to begin with. Feel free to keep picking my comments apart with technicalities, but you have noted nothing substantial enough IMO, to lead me(or probably anybody else reading) to believe the wire would melt, despite everything my own knowledge, experience, and research has told me, so I guess I can just walk away from this. At the end of the day, the #12's to the baitwell in the boat don't melt, my trucks headlights don't melt, the cheap 10 amp car battery charger doesn't melt...........But if I ever stumble across a good 1.1 ohm/567.5watt resistive load, I'll hook it up to a set of 6s2p packs with a 6' extension cord and send you the video, complete with a clock and IR readings, so we know for sure.
Until then, I guess I'll just "agree to disagree".
Feel free to delete all of it, it's your thread. I do feel, though not all relevant to capacitors, there actually is some educational stuff in here between the 2 of us, if you get through our tiresome banter.
Cheers
If you missed it, the question in the link was:
"Will 4A at 110v AC lead to a greater temperature rise than 4A at 24v DC in the same wire?"
The answers......
"No, it won't. The heating is caused by the I²R loss of the wire and not the voltage drop. The 4A AC is an RMS (Root Mean Square) value which is the energy equivalent of 4A DC."
"Also, thermal heating is a function of current only, not voltage"
"The temperature rise along the length of a cable depends only on the current it is carrying, the cross-sectional area and the material it is made of."
Or the one that backs up what I said about getting a voltage drop, but not more heat......
"However, with low voltages, it is generally more important to minimize voltage drop: if the cable carrying 4 amps has a resistance of 1 ohm per conductor, then it will be dropping 4V along the length of each conductor. So your 24V DC appliance will only be getting 16 volts! (4 volts are lost in the positive supply and another 4 volts in the negative return.) You might well want to use a thicker cable which will have less voltage drop. But a 110V AC appliance would be getting 102 volts at the far end of the same cable, which is a bit nearer the mark. Either way, the cable will be dissipating 32 watts of heat along its length." (And as I pointed out, our wire was already rated to dissipate the heat produced, the resistance of a 6' run at a safe initial operating temperature is hardly enough to trigger a cycle of thermal runaway)
I'm not sure what you're basing your "heating profile" on, but the above is some of the information that supports what I have spoken of all along. And even if you have some kind of calculated discrepancy, it's not enough to melt the wires.
All of these are perfectly in line with what I have said from the start, and nowhere along the way did I change that, not sure what you are talking about. In a purely resistive circuit, the RMS readings for AC current and voltage are basically interchangeable. In your electronics circuits with capacitors, induced voltages, pulsing, etc., those equations are an evolution of AC theory, just a little more involved. So yes, AC theory is relevant, much of it is actually interchangeable.
You are the one that said you weren't talking about your toaster, now you are hooking it up to 480vac to prove what? The numbers in your irrelevant scenario don't even make sense! When you quadruple the voltage to a resistance you quadruple the current(it wouldn't stay at 22.7) the wires will fail,... really? Isn't that kind of what I was getting at when I said you have to go way out of the ratings for it to fail? I just referenced 480v in terms of it producing the same heat in the wire at the same given amperage......Let me spell it out again though, if you hook the toaster up to 480v, it will draw 99 amps(for a very brief second), that is 47.5kw(not 11kw). Kind of like if you hook it up to 25vdc it will only draw 5.15 amps, we've already covered this, the toaster is irrelevant, your scenario doesn't even make sense, we are talking about a wire, with a given fixed amperage, at 2 different voltages.
This is copied/pasted from your example......"AWG#12 at 110VAC will carry 2400W... for 33' !!!!!!!!"
Did I miss the part where this becomes DC, bravo? Maybe you had a typo.
BTW, I think you misunderstood Cooper, I'm pretty sure he was implying that sometimes the copper tube, when sized correctly, would work better than ANY stranded wire, as in even one with more surface area."cardboard tube clad in copper would carry a better signal than ANY multi strand wire at a very specific diameter and frequency." "more skin= more transfer is just not the case".
Read his words again.
And I did not claim wiring boats as my father's profession, just that he does it. He has retired from the phone company, where he managed the projects and maintenance of the building systems and infrastructure for several large buildings in Boston. But his heart has always been in his and my brother's commercial tuna boats, just so happens he has the background to do a lot of different things(like basically build and wire the boats), but he does still renew his master electrician's license.
BTW, if you've never seen a 900 lb. bluefin Tuna be stopped dead in it's tracks by electricity coursing through the first 150' steele cable line of a harpoon dart, through another 70' of saltwater, back to a ground plate under the boat, it is a sight to behold for any electron aficionado.
As entertaining as this healthy debate has been, you have had a few days now, and still haven't given any solid evidence of your original claim. In fact, judging by the way you switched from skin effect, to thermal runaway, to grasping at straws about heating profile, to bags of horse $hit and irrelevant scenarios like quadrupling voltage and current, I'm still wondering what you based the original statement on to begin with. Feel free to keep picking my comments apart with technicalities, but you have noted nothing substantial enough IMO, to lead me(or probably anybody else reading) to believe the wire would melt, despite everything my own knowledge, experience, and research has told me, so I guess I can just walk away from this. At the end of the day, the #12's to the baitwell in the boat don't melt, my trucks headlights don't melt, the cheap 10 amp car battery charger doesn't melt...........But if I ever stumble across a good 1.1 ohm/567.5watt resistive load, I'll hook it up to a set of 6s2p packs with a 6' extension cord and send you the video, complete with a clock and IR readings, so we know for sure.
Until then, I guess I'll just "agree to disagree".
Feel free to delete all of it, it's your thread. I do feel, though not all relevant to capacitors, there actually is some educational stuff in here between the 2 of us, if you get through our tiresome banter.
Cheers
... ???
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