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Question about DC current flow

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wjbell

Jul 27, 2023
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Somebody told me that DC current only flows through the outside edge of a wire. So when you have multiple strands it carries more current. He said if that wire were one solid wire it would carry less current. Is this true?
 

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Delta Prime

Jul 29, 2020
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Believe it or not the simple question you ask is application specific. Even though you have narrowed your question down to only DC ampacity of a conductor stranded versus solid while mentioning the outside edge of a wire.
One may also think that a given length of solid copper wire has a measurable resistance . Therefore if you lay the same given length of solid copper wire in parallel and connect the ends that resistance would be cut in half allowing more current to propagate along the entire length of the conductor because of less resistance . If you noticed I never said current flow and or "current caring capability" ...Cuz you must dive into the world about the physics of conductors and insulators which is beyond the scope of this site. So do you have a specific application in mind?
 
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Martaine2005

May 12, 2015
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physics of conductors and insulators which is beyond the scope of this site.
You mean beyond the scope of this thread!
I know a man who hates ‘current flow’, he insists that ‘charge flow’ should be used instead. As ‘current flow’ = charge flow flow!.
Very pedantic indeed :):) but correct.
I say no more…
 

Delta Prime

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Given... I had to look that one up! ;)This forum is dedicated to electronic circuit theory. In that context current flow is applicable. "And carry DC current with the same voltage drop in a given circuit. which was never given. "
I will follow your lead...
But correct.
I say no more...
:);)
 
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wjbell

Jul 27, 2023
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Okay thank you for all the replies. The application is a 12 volt auto battery powering a 4000 Watt inverter. The length of the power wire is about 4 ft and it's 1/0 or 0/1 gauge however you write it.
 

Bluejets

Oct 5, 2014
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What you need to be concerned about with lv is the voltage drop over the cable length and whether or not your connections are up to the job (also points of voltage drop).
 

wjbell

Jul 27, 2023
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What you need to be concerned about with lv is the voltage drop over the cable length and whether or not your connections are up to the job (also points of voltage drop).
Yes, I know. I think my connections are just fine the only thing I can do better is put a second battery with a battery isolator right next to the inverter.

The reason I asked this question is just out of curiosity. To find out if what I was told was true or not.
 

Delta Prime

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The reason I asked this question is just out of curiosity. To find out if what I was told was true or not
Post number 7 nailed it!
I just can't help but to add...
The way it was told to you is incorrect but again @crutschow
Nailed it!
 

Ratch

Mar 10, 2013
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Quote from

Martaine2005:​

I know a man who hates ‘current flow’, he insists that ‘charge flow’ should be used instead. As ‘current flow’ = charge flow flow!.
Very pedantic indeed

I am the man that the above responder is referring to. If I were Lord Byron, the famous English poet, I would use my poetic license and write something like "The sparkling stream flowed through the green meadow." That sentence might sound nice, but grammatically it is redundant and ridiculous. The word "stream" already implies water flow, and water does not flow twice. A land surveyor should say 'a stream exists within this meadow."

Similarly, you should say "current exists", "current is present", "charge flow", but not "current flow" because current already means charge flow.

Let me burst another bubble. R=V/I is NOT Ohm/s law. That relationship expressed by that equation is the definition of resistance and a definition is not a scientific law. Ohm's law is a PROPERTY of a material with respect to its linearity of current though it versus voltage across it. Tungsten wire obey Ohm's law, but a junction diode does not. Before you call me a kook, keep in mind I can back up what I say with three reputable physics textbooks. Ratch
 

Martaine2005

May 12, 2015
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Well, that didn’t take long:):):)
Now all we need is @colinmitchel to say “no” :):)
 

davenn

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OK have deleted a lot of off topic posts and closed the thread
as it is wandering way off course

Thanks to all that gave the OP good insight

cheers
Dave
 
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