Wire datasheet interpretation - Page 1
Forum section: electronics / beginners

author: gary_01
author_rank: Newbie
timestamp: March 06, 2018, 07:32:33 pm
content: Looking atthis datasheetfor 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)*2FAnyone 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'sdatasheetlists:(10/0.12*1C+28/0.12)*1CAgain, 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

author: Jwillis
author_rank: Super Contributor
timestamp: March 06, 2018, 08:10:27 pm
content: 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

author: Monkeh
author_rank: Super Contributor
timestamp: March 06, 2018, 08:27:26 pm
content: 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.

author: tooki
author_rank: Super Contributor
timestamp: March 06, 2018, 08:29:10 pm
content: I would interpret it as:Two conductors, each consisting of 14 strands of 0.12mm diameter wire.*0.12mm = 0.0113mm^214*0.0113 = 0.158mm^2 = 25AWGIf 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 = 26-27AWG28 strands of 0.12mm diameter = 28*0.0113mm^2 = 0.316mm^2 = 22AWGI’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...)

author: Monkeh
author_rank: Super Contributor
timestamp: March 06, 2018, 08:34:21 pm
content: Quote from: tooki on March 06, 2018, 08:29:10 pmTell me about it. Oohh, but some existing posts might get corrupted (.. fairly unlikely). What about all our new posts being corrupted?!

author: tooki
author_rank: Super Contributor
timestamp: March 06, 2018, 08:41:32 pm
content: Quote from: Monkeh on March 06, 2018, 08:34:21 pmNo kidding. Converting text from [any 7- or 8-bit encoding] to Unicode is trivial. It’s the reverse that’s hella tricky!

author: Monkeh
author_rank: Super Contributor
timestamp: March 06, 2018, 08:44:52 pm
content: That coaxial one really is pathetic.I make up DC cables with this:http://www.tensility.com/pdffiles/30-00338.pdf20AWG - and it's still the same 3mm diameter. Mind you, it's a sod to get into the plugs!

author: gary_01
author_rank: Newbie
timestamp: March 06, 2018, 10:07:17 pm
content: Thanks everyone.