stranded wire, does AWG size include plastic sleeve? - Page 1
Forum section: electronics / beginners

author: HobGoblyn
author_rank: Unknown
timestamp: September 13, 2020, 02:05:40 pm
content: Need to replace cables going from my 3d printer power supply to the main board.24 volts.The strands (together) are AWG 12 but the entire wire is AWG 8.Which should I be buying please?Thanks

author: HobGoblyn
author_rank: Unknown
timestamp: September 13, 2020, 02:08:55 pm
content: Doh, maybe I should try reading whats on the actual wire16AWGWhich must mean it's just the cable and not the sleeve and I screwed up my measuring

author: Jwillis
author_rank: Super Contributor
timestamp: September 13, 2020, 02:12:24 pm
content: Diameter of conductive material Not including insulation.

author: Quarlo Klobrigney
author_rank: Super Contributor
timestamp: September 13, 2020, 03:01:40 pm
content: And the space between the conductors and the atoms of air? Not included.Quote from: Jwillis onYesterdayat 23:12:24

author: Ian.M
author_rank: Super Contributor
timestamp: September 13, 2020, 03:40:11 pm
content: Only approx 90% of a stranded wire that hasn't been die-formed will be the conductor. (Seehttps://en.wikipedia.org/wiki/Circle_packing)Therefore stranded wire requires at least 10% extra measured core area to give the same CSA as solid wire.

author: Monkeh
author_rank: Super Contributor
timestamp: September 13, 2020, 03:56:16 pm
content: You don't size the conductor by the insulation.If you want to accurately measure, count the strands and measure the diameter of one strand.

author: tooki
author_rank: Super Contributor
timestamp: September 13, 2020, 04:30:40 pm
content: Exactly. What matters in terms of current carrying ability is the cross-sectional area. When you see the diameter of a wire somewhere, it means the diameter ofsolidwire (i.e. one strand). You cannot accurately determine the AWG (nor mm2) of a stranded wire by measuring the diameter of the strand bundle. You can approximate it as Ian.M said, but to actually know, you need to measure and count the strands as Monkeh said.And you most certainly cannot accurately determine the (copper) size of any wire by its insulation!A 16AWG wire is 16AWG whether it's insulated or not. Wires come in all kinds of insulation, from none at all (bare wire) to thin enamel to regular PVC to slightly thick silicone for test leads, to super thick multi-layer insulation for high-voltage applications. (Like spark plug wire.)

author: Alti
author_rank: Frequent Contributor
timestamp: September 15, 2020, 05:42:51 pm
content: Quote from: HobGoblyn on September 13, 2020, 02:08:55 pmRegarding cross section and "does AWG size include plastic sleeve"That depends oncountry of origin and specific standards that apply.

author: Monkeh
author_rank: Super Contributor
timestamp: September 15, 2020, 05:57:31 pm
content: Quote from: Alti on September 15, 2020, 05:42:51 pmNo it doesn't. Don't confuse fraudulent goods with different standards.

author: vk6zgo
author_rank: Super Contributor
timestamp: September 15, 2020, 11:42:34 pm
content: Quote from: Alti on September 15, 2020, 05:42:51 pmThese days, AWG is only a standard size in North America, so anything using that gauge system should be optimised for that market.Back in the day, B & S, SWG, etc, certainly in Oz, & I believe, more widely in Commonwealth,countries, referred to solid wire, like you might wind a coil or transformer with.Stranded wire was identified by the strand diameter & number of strands, hence you found sizes like:-23/0076, 7/010, 10/010, 3/029, etc.In these examples, the strands were 0.0076 inches, 0.01 inches, & so on.In most cases, you would work out the diameter require for a solid conductor to carry the required current, then add 10% for stranded wire, or do what most people do----- see what other people use in similar service.In the real world you then have to use standard commercially available wire sizes, anyway.

author: tooki
author_rank: Super Contributor
timestamp: September 16, 2020, 05:24:13 am
content: Quote from: vk6zgo on September 15, 2020, 11:42:34 pmAlti wasn’t actually addressing standards, but rather just attempting a cheap shot at fraudulent Chinese junk.As for how to determine wire size: nobody (serious) goes by wire diameter any more, since solid wire is rarely used anymore outside of building wire. Instead, you go by cross sectional area. (AWG is a proxy for this, since the gauge of a stranded wire is the same as of a solid wire with the same cross sectional area.) Whether using mm2or AWG, the proper way to choose wire is to use ampacity charts for your application, or to calculate the total resistance of the wire and calculate the resultant heating, voltage drop, etc, then determining what’s acceptable in your application.