Wiring size charts, applicable to AC and DC?

[upnorthandpersonal]

What is the variable U? Is this voltage?

Also, one little side point, computer fonts often make it impossible to differentiate l from I (see what i mean ), might make sense to use capital L for length so it can be differentiated from current.

Yes, U = voltage.

I realize that a capital L is more readable, but the correct symbol is a lower case l. I'm torn

 

[Dzl]

Yes, U = voltage.

I realize that a capital L is more readable, but the correct symbol is a lower case l. I'm torn

The best solution is for fonts to move away from impossible to differentiate lowercase l's and uppercase I's. Unfortunately font designers never ask my opinion on things

 

[upnorthandpersonal]

I'll use 'proper' math symbols from now on:

R = ρ . ℓ / S

 

[Supervstech]

Hello
im trying to find out if fine stranded wire (welding cable) is more efficient for DC circuits than heavy stranded wire and why.
No one seems to offer any factual based answers, only guesses and opinions.
ive searched the internet and can not seem to find evidence.

I think my answers are factual...

Stranded for DC and household AC is ONLY for flexibility.

There is ABSOLUTELY ZERO resistance or amperage difference between super stranded, big stranded, solid, or bussbars for that matter with DC circuits. The mass of the wire is what moves the energy.

 

[orangeminnie]

Correct! Interestingly, stranded wire of a given gauge may be slightly larger in diameter than the same gauge solid wire (due to gaps between the strands), but should have the same resistance. Skin effect is negligible at 60Hz, and zero at DC. Welding wire is great for flexibility, and holds up well for installations subject to movement and vibration. If you're stationary, coarser stranded wire is fine, and less expensive, but can be a bear to bend in tight places.

 

[Frank in Thailand]

but overall - like my grandmother told me -- when in doubt - go BIGGER ...

AND do whatever you can to either get UV shielded cable or put the cable in the automobile electrical cable flex hosing ... The sun is the number one killer of RV cables ...

View attachment 8548

Thank you for the chart and usable insight.

Going back and forth over technical discussion, including the AC/DC discussion, masive or stranded...
Not to mention aluminium, copper or combinations...

While alu and alu+copper have its own good benefits, 95% of "our" (forum readers and writers) are better of with pure copper.
Probably the 5% have only slight profit for ALU or alu mix.

Listen to @ghostwriter66 grandmother.

Yes, bigger is better, and please, don't mix metal (unless soldering)
Mix metal = copper cable with aluminium lugs
It's just not worth it.
They will (in many/most cases) give you issues

You want to work cheap or safe?

I assume we all value our lives and investment made in the equipment.
Use the list provided, better go one step bigger, it never hurts and give room for extending.

Stiff bar, Flexible strands?
Like many have proven, stiff bar is "better" for DC, but really difficult to work with!
For the short distance we use (under 1000 meter) it is marginal, hardly worth any discussion.

Use the graph and advice that is provided, and your installation will be free of strange ghost.
Thanks to ghostwriter

 

[Dzl]

Thank you for the chart and usable insight.

Going back and forth over technical discussion, including the AC/DC discussion, masive or stranded...
Not to mention aluminium, copper or combinations...

...

You want to work cheap or safe?

I assume we all value our lives and investment made in the equipment.
Use the list provided, better go one step bigger, it never hurts and give room for extending.

Use the graph and advice that is provided, and your installation will be free of strange ghost.
Thanks to ghostwriter

View attachment 10375

Personally, I use and recommend marine rated (ABYC/USCG compliant) wire.

Its an easy way of ensuring the wire is (1) Pure copper (2) Fine stranded (3) rated for 600V (4) Clearly marked standardized temperature rating, 105C being the most common.

There are a ton of little decisions to think about when designing an electrical system, and a ton of technical things to stress over. By sticking to marine rated, UL listed wire, and marine wire size charts and calculators, it saves me a good bit of thinking and stressing.

More info:
ABYC E-11 electrical standards
UL-1426
Marine DC wiring basics


One note about that chart, its specific to 12v, using it for 24v etc isn't a problem or safety issue, but the wire size it recommends will most likely be a gauge or two thicker than it needs to be for 24v+.

Here is the chart that the Blue Sea Chart posted above cites as its source and is based off of, (its a little less pretty but has separate tables for 12v and 24v):


Or you can use Blue Sea's circuit wizard which allows you to select 12v, 24v or 32v (sorry no 48v)

 

[Lobo]

I think my answers are factual...

Stranded for DC and household AC is ONLY for flexibility.

There is ABSOLUTELY ZERO resistance or amperage difference between super stranded, big stranded, solid, or bussbars for that matter with DC circuits. The mass of the wire is what moves the energy.

Thank you
I believe this answer is the answer to my thread on conductor efficiency.
I can find nothing in the NEC or other furums regarding any difference in conductor efficiency difference between fine strand conductors and course strand conductors.
I will build my system with the course stranded conductors that i use daily and have abundant access to.
Wish i knew how to move your answer over to my thread for others to see.
Thanks again