According to xxx :
On Thu, 05 Jan 2006 16:26:03 -0000, (Chris
Lewis) wrote:
According to Mark Lloyd :
I wonder how hot 14AWG wire would get with a constant 30A current.
Depends on how much thermal insulation there is.
The free air melt current of bare 18ga is 100A. Yet, the "safe"
current for insulated 18ga is around 5A.
Heavily buried in insulation, I'd expect a 14ga wire to melt with 30A
continuous. In free air, it'd be difficult to tell it was getting warm.
14ga at 30A will be generating about .9W/foot. It's all a matter
of heat dissipation.
If a copper wire in free air melted, you'd have hot drops of molten
copper falling around. Some may even fall on you.
Well, yeah, if the overcurrent wasn't too high. If the overcurrent
was high enough, instead of melted copper droplets, you get copper
vapor and even plasma.
Not sure how that's relevant here tho.
If a copper wire is well insulated, you get something very different.
Liquid copper becomes a superconductor (as long as it's contiguous,
and contained by plastic insulation). You can also obtain liquid state
breakers (open circuit if current falls below threshold), switches,
etc... at an electrical supply house (not available at Home Depot).
Operating your wiring that way will greatly reduce your utility bills.
Good joke.
Note that the above paragraph is meant to be read only by
knowledgeable, intelligent people who can determine it's state of
truth.
Eg: it has no truth.
Copper doesn't appear on the super conductivity table at all. If it
ever becomes superconducting, it's going to be only at temperatures
infinitesimally close to absolute zero (-273C). It certainly ain't
at copper's melting point 1084.62C.
I don't know of any plastics that stay together at 1084C.
Let's say that all of the above was true. It'd only save you
a few percent of your electrical bill (in-house circuit losses
of a few percent).
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.