Re: [CAD_CAM_EDM_DRO] Re: Wire size question...

On Wednesday 06 April 2005 09:51 pm, turbulatordude wrote:

> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "Jeff Goldberg" <jeff@w...>
> wrote:
> > If it enclose in a conduit, then #10 AWG. If in open air, can use
> > #12. On this distance, there is no appreciable price difference, so
> > unless you have an important reason to go smaller, might as well use #10
> >
> > Jeff
>
> I've seen a lot of numbers tossed around for wire sizes and currents
> and such.
>
> I thought that residential wiring was 12ga for a 20 amp service. that
> being an insulated wire bundle, NOT in free air, but between walls, and
> with a run of less than 100 feet. (increase one ga for over 100 feet
> to reduce voltage drop) Kinda fast and loose, not cast in stone stuff.
>
> And, I thought 10ga was good up to 30 amps under the same condioons ?
>
> FREE AIR would be like in an enclosure where the heat of the wire is
> easily dissapated, and that increases the wire ampacity. (OK, current
> carrying capabilty, but I just like the word Ampacity)
>
> Anyway, are you baseing that on rule of thumb, some standard or code or
> something ?
>
> this link clearly states FREE AIR, but I have seen people use it as
> gospel for any and all applications.
>
> http://www.allaboutcircuits.com/vol_1/chpt_12/3.html
>
>
> Dave

This stuff all assumes certain things about what's allowable as a voltage drop
on standard (120v or 240v) circuits, which may not be the case when talking
about a somewhat lower voltage at the output of a power supply. That's
probably the main issue, how much voltage one can afford to lose in that bit
of wire...