I know y do it , but why !

Tidbits and Snacks


https://www.firefold.com/blog/solid-vs-stranded-cable-pros-and-cons/

BFL13 wrote:
There is also the difference between the stranded type with the thicker wire strands, and the type with a kabillion silky thin strands.

Can't say which has which, but they have cords that are especially flexible in freezing temps. I find the silky ones are very hard to use in a set-screw terminal, as they keep pulling out. Need much "strain relief".

I think one type is for "welding" wire, but I have no idea why.

Good topic! Should learn something I think.

The more strands in a given size wire the more flexible it is. The wire with hundreds of very fine wire is often called "welding cable" because that application typically calls for a high degree of flexibility so the welder can more easily manipulate the welding tools. The fact remains though that a 10 AWG wire will have exactly the same total metal cross sectional area and total circumference whether there's one strand or a thousand. The physical diameter of the multi-strand wire will be a bit larger than the single strand due to the air spaces between the strands, but both will have exactly the same 30 amp ampacity rating.

Never thought about it. :h

I guess I just assumed wire that was used for anything that moved, flexed, rolled, stored away, bent (like extension cords) was stranded.

Anything that was stationary, like wiring inside a wall that would never move, was solid.

Maybe I'm wrong, who knows?

Visit a plant that manufactures electrical wire. Solid wire is much less expensive to manufacture. Solid wire occupies less area. Solid wire has no need to flex.

And you will not see single strand 6 awg because it could not be bent by hand.

The most flexible wire I have yet encountered is rope stranded high strand count silicone sheathed wire. Neoprene welding cable is appreciably stiffer.

INSULATION
The toughest I have ever encountered is a hybrid mix I have used off of the space shuttle orbiter refit project. Tougher than aircraft teflon my 2nd choice. EDPM is tough (Diesel locomotive wire). Then Cross Link, PVC, neoprene and finally silicone. Silicone wire is super inside of a chassis. The limpness allows for almost impossibly tight routing.

There is also the difference between the stranded type with the thicker wire strands, and the type with a kabillion silky thin strands.

Can't say which has which, but they have cords that are especially flexible in freezing temps. I find the silky ones are very hard to use in a set-screw terminal, as they keep pulling out. Need much "strain relief".

I think one type is for "welding" wire, but I have no idea why.

Good topic! Should learn something I think.

Not even close to right. Stranded is used when the wire will or might flex. Solid when no flex is expected.

agesilaus wrote:
If I remember my intro to electrical engineering in ac current flows thruout a conductor. With DC current follows the skin of a conductor, stranded wire provides more skin aka surface area than one solid conductor. However I'm sure others who really know about this will reply....

Sorry, but that's reversed. The "skin effect" applies to AC, not DC. Wires of the same AWG have exactly the same total cross sectional area and can carry exactly the same current. Note that wire ampacity tables do not differentiate between single and multi-core wires.

AWG Wire Gauges Current Ratings

If I remember my intro to electrical engineering in ac current flows thruout a conductor. With DC current follows the skin of a conductor, stranded wire provides more skin aka surface area than one solid conductor. However I'm sure others who really know about this will reply....

Well I didn't remember it too well, I got it reversed and the skin effect only occurs at higher frequency than 60 Hz.

That's really not the case overall. There's plenty of stranded wire used in AC circuits, just as there's plenty of solid wire used for DC circuits. In the RV world, the difference is primarily the ready availability of off the shelf products for the AC side, which usually mean solid wires, while the DC side is more commonly built with stranded wires to better withstand the rigors of road travel. For AC, one common exception is the stranded coiled wiring used to supply power to outlets, etc., in slides. Running all stranded AC wiring in an RV would also require running conduit per the NEC, something that's not required for low voltage DC wiring.