Current travel

[Charliekilo]

Does electricity travel thru the conductor or over the outside?
Will a solid or a stranded conductor of the same diameter carry more current?

 

['04 Cummins]

http://en.wikipedia.org/wiki/Skin_effect

Most current is concentrated on the outer portion of the conductor. Solid wire has slightly more ampacity per cross-sectional area, negligible difference though.

 

[Stuart in MN]

Skin effect is for AC current. The layer gets thinner as the frequency is increased, but at 60hz it's essentially a non-issue for homeowners. Quoting from the Wikipedia article, at 60 Hz in copper the skin depth is about 8.5 mm, which is about the thickness of a 1/0 wire - so for any wire smaller than that the current is traveling through the entire wire.

 

[kbs2244]

Didn’t the high voltage, cross country lines, guys go to hollow wires because of this?
Less cost and weight.

 

[racingtadpole]

Does electricity travel thru the conductor or over the outside?
Will a solid or a stranded conductor of the same diameter carry more current?

Short answer is it depends..

What sort of voltage, what frequency.

At DC and Household supply type frequency its a non issue. They are both the same. Use the stranded, its easier to work with.

Skin effect doesnt really need to be considered until you start talking about the RF end of the spectrum.

 

[ddawg16]

Does electricity travel thru the conductor or over the outside?
Will a solid or a stranded conductor of the same diameter carry more current?:dunno:

Skin effect is for AC current. The layer gets thinner as the frequency is increased, but at 60hz it's essentially a non-issue for homeowners. Quoting from the Wikipedia article, at 60 Hz in copper the skin depth is about 8.5 mm, which is about the thickness of a 1/0 wire - so for any wire smaller than that the current is traveling through the entire wire.

As Stuart pointed out....skin effect does not take place on conductors smaller thatn 1/0 wire.....hence, for your typical 12 or 14 awg wire....stranded or solid will have the same performance.

 

[Charliekilo]

Thanks guys. Years ago in Hi School I was taught on the surface and stranded was better. Lately I read solid was the better conductor.
May you find peace, health and love in your gifts.

 

[theoldwizard1]

At DC and Household supply type frequency its a non issue. They are both the same. Use the stranded, its easier to work with.

I always wondered why "romex"/NM was not made with stranded wire. My only guess is that solid wire is cheaper and the extra flexibility is not required like in lamp cord/"portable cordage" (i.e. extension cords).

Terminating a solid wire to a screw may be more durable than a stranded wire.

 

[RPH]

Work with high frequency induction heating equipment. The skin effect does come apparent at about 10 kHz. Most of the lower frequencies they don't worry about it. The concern there would be wall thickness of the copper tube used as conductors. In stranded wires the surface area increases for the skin effect but you need to utilize Litz wire. Litz wire is stranded but the strands are insulated from each other like magnet wire. This allows the surface area for current carrying to dramatically increase.