KnuKonceptz claimed ampacity

[stocker08 10+ year member]

You ****

 

[MakeshiftAudio 10+ year member]

You ****

//content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif

Not as much as your hiphop. Ur mad, troll.

 

[sundownz Pro Seller]

*laughs*

Sig away //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[McIntosh 10+ year member]

RF is the way to go //content.invisioncic.com/y282845/emoticons/thumbsup.gif.3287b36ca96645a13a43aff531f37f02.gif I design high power RF amplifiers //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif
As far as this discussion is going.... the OP is trolling. From my memory, McIntosh is technically correct in the strict term of ampacity.... it does not depend on length. The thing that people I think are missing is that whatever you have connected to the end of the wire is expecting a certain voltage so it can make a certain power. Length of wire certain determines voltage drop.

For example, if you have an amp that needs to have 3600W (12V x 300A) input into it, a 5 ft run is fine because its voltage drop is going to be tiny (pretty much 0). Therefore the wire is still gonna draw 300A. Assuming this is within the ampacity of the wire (and in 99.9% of real world cases ampacity is determined by the insulation of the wire, not the wire itself), everything will be fine. Now if you switch to a 200ft cable of the same ampacity connected to the same amp, lets say your voltage drop is 2V. That means that the same amp now has to draw 360A (10V x 360A) to get the same input power. Now if that is higher than the ampacity of the wire, problems come up //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

This is turning into a theory vs application debate. Next should we debate changing the common convention of current flowing from + to - when the electrons actually flow from - to +? As stated earlier, most ampacity is actually limited by the insulation anyway. When the insulation fails, the wire is considered to have failed. That also means the wire is scorching hot.... all bad things //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif I do EE, not ME, so I do not know all of the heat transfer sides, but I'm sure it is non-linear and at longer lengths the heating will not be even all along the wires.

For the TL,DR folks,

McIntosh is technically correct, is trolling, and needs to realize that the manufacturer's claims are made based on their application not the strict definition of ampacity. In application, length of wire will certainly matter.

Which direction the current flows is divided between two schools. The hole theory or not. It really doesn't matter so long as you apply the same theory throughout your circuit. The final result is the same. Conductor ampacity is indeed based upon insulation type and termination point temperature rating. Current heats the wire. Its a matter of when the insulation can no longer insulate the conductor. Conductor heating is simply I squared R loss. It is obviously quite linear as current cannot change. What you put in one end comes out the other end. You can't have 300 amps at each end without having 300 amps at every point in between. Amps are a defined number of electrons/second (a coulomb). To use the old analogy: a garden hose. Amps are gallons per unit time. What you put into one end of the hose naturally comes out the other. The length of the hose does indeed influence how much you get out of the other end (voltage drop). The amount put in one end exactly equals the amount coming out the other end, no matter what. That also exactly equals the amount at any given point along the hose's length. My gross example of 2' versus 2000' (or whatever I cited) absolutely holds true. Current in = current out = current along every inch. Enter real world. 2' versus 20' for example. No change in ampacity, as there wouldn't be for 2000'. The wire can only safely carry a specific amount of current. The real world voltage drop (and associated increase in current draw to achieve the same power) is a different story. It was not my intent for anyone to calculate the voltage drop on 2000 feet of wire nor the increase in amperage needed to maintain a given power. My point (which seems to have been lost) is that a conductor's ampacity has nothing whatsoever to do with it's length.

 

[ngsm13 5,000+ posts]

My god, you are a regurgitator...

nG

 

[roarzorz 10+ year member]

If it wasn't for copy/paste from Google he wouldn't have anything to say. Still just trying to argue.

 

[-Leister- 10+ year member]

Lmao!

 

[McIntosh 10+ year member]

Sweet. Let's see, are we talking about resonant RF amplifiers? //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif If so, shoot me a PM.
Not directed at g35x, supporting his statement, if you look at the (REAL) ampacity charts, you'll notice that they're based on the max rated insulation temperature. I believe that the standard grades are 75*C, 85*C, and 95*C, which is 167*F, 185*F, and 203*F respectively. I would consider that pretty hot, considering the last temperature is almost water's boiling point.

Yeah, it all boils down to length. When I bench my amps, I have 4/0 cables (I forget, something like 4-5', one run per rail) from my SMPS and battery bank, all the way to the point of a couple inches away from the amp which then goes into a reducer if needed or distro that I machined to allow it to hook to dual 12V power connectors if it is an amp that has dual inputs. (See AB VFL 400.1, Orion 2500D)

Thanks for the praise, I hope you don't mind if I sig that, it's kinda cool being praised by you. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

The "standard" temps are actually 60, 75 and 90C (140, 167 and 194F) in the REAL ampacity charts. Its a moot point for sure. 4/0 you say? Why? 1/0 is good for "burps" supposedly over 800 amps and 300+ continuous. Yeah it all boils down to length. Sure. 194F is frickin HOT whether the wire is a foot long or 20 feet long..

 

[roarzorz 10+ year member]

:facepalm:

 

[ejschultz 10+ year member]

This guy just needs to STFU. You've got no one on your side. Maybe that should tell you something.

 

[andrewmoore13 10+ year member]

This guy just needs to STFU. You've got no one on your side. Maybe that should tell you something.

Nah he's right. Of course he's right. He's smarter than all of us. //content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif

NOT

 

[McIntosh 10+ year member]

This guy just needs to STFU. You've got no one on your side. Maybe that should tell you something.

I'm not a clown by profession anymore so I don't have to impress children. My name is Bubbles. I need to say thanks. You did me more than a few favors. I remember you quite well. Thank you.

 

[Pioneer~Saturn 5,000+ posts]

End this madness

 

[power-fanatic07 5,000+ posts]

fail

 

[ejschultz 10+ year member]

I'm not a clown by profession anymore so I don't have to impress children. My name is Bubbles. I need to say thanks. You did me more than a few favors. I remember you quite well. Thank you.

I don't remember doing that when I was a kid. The only bubbles I blew were with bubble gum. And if you did do that, you're one sick mofo.