"Bob La Londe" wrote in message
...
"Ned Simmons" wrote in message
...
On Sat, 1 Jan 2011 13:50:28 -0700, "Bob La Londe"
wrote:

I was just reading the manual for the Mitsubishi VFD in the cabinet on
the
Hurco. I got all excited when I found it could be run off of single
phase
power, not just 3 phase. It even has a table showing is capacity when
used
with a single phase input. Sadly its not quite enough.

But probably enough to get you started. You may overstress the input
rectifiers and filter caps, but what's the worst that can happen?
You'll shorten it's life and end up with a nfg VFD, which isn't any
worse than no VFD at all. Unless it's new enough to have some resale
value -- what model is it?

Mitsubishi Freqrol - A024 3.7 Kw. Says it can provide 7 amps out on
single pahse 230 in. The motor says 14 amps on the data plate. (Also, my
Hurco manual says this is a 4HP motor, not a 3HP as some have indicated.)
Not particularly new. I was thinking if I ran a cross a medium duty mid
size lathe or a bigger drill press it would make an excellent speed
control for that. I don't think it has a lot of resale value. Of course
I don't even know if it works yet. Time to go borrow a scope and fire it
up I guess.

Actually, yesterday and today I have been just going through the machine
to learn how everything goes. I haven't even leveled it and bolted it
down yet. Overall I am impressed with it. It was built to last.


I use a 10HP VFD single phase on my 7-1/2HP lathe motor. I let my lathe run
idle and the VFD said it was using something like 14A, I measured the amps
going into the drive and the drive was only using 5A from the wall. What
the VFD draws from the single phase is closer to the true power and what it
supplies to the motor has the bad power factor of the inductive motor.

The point I'm attempting to make is that it's worth a try, you may not be
able to get a continuous 4HP from your motor but 2HP average with 3HP peaks
(drives usually put out 150% of rated output for a minute or so) isn't bad.

RogerN