Wire datasheet interpretation

[gary_01]

Looking at this datasheet for a DC cable on farnell, I'm trying to understand what gauge the wire actually is so I can determine a reasonable current limit. The datasheet doesn't give an AWG but instead notes:

(14/0.12*1C)*2F

Anyone know how to interpret that? Is it 14 strands with a total diameter of 0.12mm or 0.12mm per strand? Or neither?

Also, what is 1C and 2F referring to? As a guess it seems to be 1C meaning the 14/0.12 is per conductor and 2F perhaps meaning both are the same size? Seems an odd way to write it if so.

Another cable's datasheet lists:

(10/0.12*1C+28/0.12)*1C

Again, how is that interpreted? That one at least lists 1.5A for current rating, but I'd still like to know how you get from the above to a final wire gauge.

Little confused, if anyone can clear it up I'd appreciate it

[Jwillis]

I use this chart and go by around 8- 15 % of the fusible current rating.That's generally the safe area before excessive heating occurs.https://en.wikibooks.org/wiki/Engineering_Tables/American_Wire_Gauge

[Monkeh]

That's a weird way to note it, but what they're trying to tell you is each conductor is comprised of 14 strands of 0.12mm diameter. I suspect 2F indicates two condutors in a flat (really figure of 8) assembly.

So that makes this wire 0.158mm² or roughly 25AWG. An odd size. Good for 1A, but I wouldn't like to use anything longer than a 2m assembly.

The second is a coaxial cable - you have a centre core and the much larger outer conductor. 0.11mm² for the core (yeesh, 27AWG), but much assisted by the screen at 0.316mm² - close enough to call it 22AWG. For the shortest 1.5m assembly that's going to be a drop of about 400mV on the core and 125mV on the screen at 1.5A. Again, I don't think I'd want to use 3m, 5m, or 10m examples of that.

[tooki]

I would interpret it as:

Two conductors, each consisting of 14 strands of 0.12mm diameter wire.*
0.12mm = 0.0113mm^2

14*0.0113 = 0.158mm^2 = 25AWG

If that’s correct, I wouldn’t be chasing a lot of current through it. :/

As for the second one, similar math:
10 strands of 0.12mm diameter = 10*0.0113mm^2 = 0.113mm^2 = 26-27AWG
28 strands of 0.12mm diameter = 28*0.0113mm^2 = 0.316mm^2 = 22AWG

I’m assuming that despite the photo, it’s a coaxial wire, which would explain why one conductor is so much beefier than the other.


In a nutshell, both of those are really, really thin cables...



*Despite the fact that in metric, wire is normally given in cross-section, not diameter, but 14*0.12mm^2=1.68mm^2 would be fairly hefty wire, about 15AWG, probably too thick for those plugs. And moreover, the outer diameter of the wire is specified at 1.8mm, and the diameter of 1.68mm^2 solid wire would be 1.5mm, leaving only 0.3mm for insulation — and this is stranded, which will be fatter.


(Really, eevblog doesn’t support the almost-equals sign, either? I wish they’d join the 20th century and update to Unicode...)

[Monkeh]

(Really, eevblog doesn’t support the almost-equals sign, either? I wish they’d join the 20th century and update to Unicode...)

Tell me about it. Oohh, but some existing posts might get corrupted (.. fairly unlikely). What about all our new posts being corrupted?!

[tooki]

(Really, eevblog doesn’t support the almost-equals sign, either? I wish they’d join the 20th century and update to Unicode...)

Tell me about it. Oohh, but some existing posts might get corrupted (.. fairly unlikely). What about all our new posts being corrupted?!

No kidding. Converting text from [any 7- or 8-bit encoding] to Unicode is trivial. It’s the reverse that’s hella tricky!

[Monkeh]

That coaxial one really is pathetic.

I make up DC cables with this: http://www.tensility.com/pdffiles/30-00338.pdf

20AWG - and it's still the same 3mm diameter. Mind you, it's a sod to get into the plugs!

[gary_01]

Thanks everyone.