Re: [CAD_CAM_EDM_DRO] Rotary phase converter

On Tue, 29 Jan 2002 14:34:36 -0500, "Carlos Guillermo"
<carlos@...> wrote:

>Hi Fitch -
>
>I appreciate your advice. I'm stuck on this for two reasons:
>
>1.) A 5hp VFD is $400 (3phase; can't find a 1-phase input yet, but
>shouldn't be that much), while to run 5hp with a rotary phase
>converter will cost twice that (I know, I could easily build one
>myself, but I have way too many projects going already)

Yup, a 5hp VFD is expensive. It would probably take about 4 hours to
put together a 7.5hp rotary that would run your lathe once you got the
motor, voltage controlled switch, electrical terminal box and start cap.
It doesn't have to be other than the plain jane converter to run your
lathe.

FWIW: That's about $100.00/hour for your time after taxes for the
assembly time.

Later, if you want better performance - spend a couple of hours and add
run caps.

>2.) I my "3hp" lathe turned out to be 5hp (the seller said it was
>3, which seemed right, but both the motor nameplate and recently
>acquired manual say 5!)

I'd believe the motor name plate. Trust me on this, a undersized VFD
isn't gonna replay the sellers words in its electronic heart and decide
not to fail because of it. 5hp is 5hp.

I think probably this should be the end of this topic. At least I'm
done with it.

Fitch