Jay Pique (in )
said:

| Assume that I have in front of the above referenced options. I can
| pick only one - a VFD, a (rotary) Phase Converter or straight
| 3-phase power for the 3-phase 16" Rockwell RAS I picked up for
| $300. In the long run, which will cost less to own and operate
| over time? Assume the 5hp VFD is $250 and the 5hp converter is
| $400. Am I likely to spend a lot more money on power if I have to
| spring for 3-phase direct? Manintenance issues with the VFD and
| converter relative to 3-phase power - and to each other?

Jay...

You might want to check out the Delta (not the same Delta that makes
power tools) VFD-B. I paid a bit more than $250 for it; but (IMO) it's
great. Mine is used to control a Colombo 5HP 0-24K RPM (in 1/10 RPM
steps!) spindle on my ShopBot and it's been absolutely trouble-free
since I got it 2+ years ago. It's fully programmable from its own
keypad - so if you wanted to, for example, have automatic braking when
you're done with a cut, you could.

The downside is that you'd want to re-wire your RAS switch so that it
provides a control signal to the VFD.

The Delta guys in Atlanta have been extremely helpful by digging out
the info and coaching me on how to control the VFD-B using an RS-485
serial port on my PC. Not sure that'd be terribly useful on a RAS, but
is great on the CNC router.

I like it! :-)

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/solar.html