Proof Wire Can Handle More Amps with DC Current

Cables, Conduits
and Trunking

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Amps is amps is amps, the wire doesn't care about polarity. whoever told you that is nuts.

Amps ain't Amps.

At high frequency the current only flows on the wire surface. So effectively the wire has higher resistance.
The AC resistance will always be higher than the DC resistance.

Google Skin Effect.

Yes, but not much. Maybe with HF, but I hope this isn't a HF question.

I almost posted a freq. vs current chart, but we have no idea what OP is doing.

I fear neither does he/she, from the question.

Let's get the OP to tell us what they're up.

You have to get well above 60hz or well larger than 12 ga before skin effect makes any difference at all. Sorry, still BS.

British Standard 7671.

Carl Quote "At high frequency the current only flows on the wire surface. So effectively the wire has higher resistance. The AC resistance will always be higher than the DC resistance."

Carl in theory that is true, but at 60 hz the skin effect is negligible on a #14 conductor. In fact it only become a factor on conductors 2/0 and larger.

i think it involves the wire insulation. think "spark plug wire"

the higher the voltage, the less resistance under the same circumstances. the less resistance, the less heat.

eh, not exactly. typically the resistance is constant, (driven by the physical cross-section of the wire, or at higher frequencies the cross-sectional area of the conductive annulus which varies with frequency, multiplied by the conductivity of the material, and to a very small extent temperature) E=I/R. live it love it. it's not just a good idea, it is the LAW.

I think you don't have any idea about what you are talking about. the thickness of the insulation multiplied by it's dielectric constant controls how high of a voltage you can place on the wire before the insulation begins to break down and arc to ground.