Re: [CAD_CAM_EDM_DRO] G201 death/repair/questions/problems (long post)

On Tue, 2003-04-01 at 22:30, Jon Elson wrote:

Jon,

> Let me get this straight - TWO G201s blew up at the same moment?

I saw smoke come from them both when they went but I can't find anything
wrong with one of them so it may be fine. The smoke may have traveled
and only appeared to come out of both. I truly hope this is the case as
one of them was borrowed.

> Something is definitely
> wrong! Fuses probably will not save them before damage, but it may
> reduce the "collateral
> damage" to one or two components, rather than making everything smoke.
> you are supposed
> to put an external capacitor at the power terminals of the Gecko drive
> if you use fuses.

I'll be adding some fuses before they go back in the box. It certainly
can't hurt to have a bit more protection.

> If only one drive had fried, I would strongly suspect a motor with an
> intermittent short.
> I wonder if there is a possibility that a very sudden power down when
> one drive shorts
> out could cause the other drive to fail?

I'm starting to think it may be one of the motors. The problem is, I've
swapped the motors back and forth a few times and with all the smoke,
it's not clear which one it was/is or if it's both. I'm going to pull
them apart and check the internal wiring as well as test for shorts to
the case. Hopefully it will be something obvious. I've metered the
windings and checked for shorts across the phases and both motors seem
to be ok by that test. They are surplus however, so there's no telling
what they went through before I got them.

Thanks for the response. With all the great help on this list I know
I'll be cutting metal in no time.

Chris