Re: blown fuse

Thanks Jon,

I replaced the fuse and so far so good. Looks like I drew a little
too much power with a deep cut and luckily nothing seems to have
been damaged. Keith

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@p...> wrote:
> Keith Clark wrote:
>
> >I was happily running my mill with Mach2 when the fuse for the
> >powersupply to the steppers blew. I was cutting with a coromill
3.0
> >inch bit with 6 inserts on hard metal. I am worried if it is
> >expected that one motor could blow a fuse if under load. I have
> >Geckos with a 75v 16 amp powersupply. I can't seem to find any
> >other problem
> >
> >
> There are a couple of possibilities. one is that the fuse was
marginal, and
> failed in the slow-heat mode. If so, you may find the fuse has a
melted
> solder look on some part of the element. If it failed in hard
overload
> mode, it likely indicates that a component has failed, and another
fuse
> will blow instantly. Hard overloads will often leave the inside
of the
> fuse tube covered in vaporized metal.
>
> What is the rating of the fuse that blew? Is it on the AC input
to the
> transformer? Full load is roughly 1200 W, which would draw 10 A if
> the power factor was perfect. Since it won't be anywhere near
perfect,
> a full load on such a power supply may cause an RMS current draw
> that could even exceed 15 A.
>
> Jon