Re: wire for motor ?

Hi Dave,

Those ratings are for High Voltage Power Transmission...

Open air wiring ratings are something like 30 and 40 amps for
14 & 12 ga.

John



--- In CAD_CAM_EDM_DRO@yahoogroups.com, "turbulatordude"
<dave_mucha@...> wrote:

>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, cnc002@ wrote:
> >
> >
> > In a message dated 12/10/2006 1:00:24 PM Eastern Standard Time,
> > washer@ writes:
> >
> > No.. you've made a common mistake. Wire has a given resitance per

unit

> > length. This resistance will cause a heat buildup in the wire when
> a current flows
> > through the wire. This is why wire is rated by it's current
> capacity (see
> > any wire chart).
>
>
> Interesting. Can I then assume that a 3 amp chopper will deliver a
> constant 3 amps to the motor ? and therefore size the wire for 3
> amps ?
>
> I can see that in a holding posistion, with the driver holding one
> phase at full power (full step) the wire would experiance the highest
> amp load. any microsteps would reduce the full load to some portion
> of full.
>
> In looking at the AWG charts the first thing that does not make sense
> is the 14 and 12ga wire. I had always assumed 12ga in a residence was
> good for a 20 amp servcie and 14ga was good for 15 amps.
>
> The AWG chart shows 12ga as good for 9.33 A and 14ga as good for 5.87 A.
>
> Dave
>