I really think you ought to put one together and see if it works for
you.

Since your limit is power available, let me tell you of one I put
together.
It was for a fishing rod blank company that had a centerless sander.
This was about twenty five years ago so I may remember somethings
incorrectly. But I think the main motor on the sander was a 5 hp
three phase motor. I used a 7.5 hp three phase motor and a two hp
single phase motor with a belt drive between the two. I forget the
size of the breaker, but it was just big enough after some fiddling.
The pulleys were adjusted until the current drawn by the single phase
motor was about 85 to 90 % of the name plate current. Some capacitors
were connected between one of the hot legs to the leg not connected to
facility power. As I remember the current drawn by the single phase
motor decreased as caps were added and then started to go back up. So
some caps were removed so current was a minimum. Then some caps were
added across the power line for power factor correction. I never try
to completely correct for power factor.
If you plot current as you add pf caps, you will see the first one
drops the current a good deal, the second one drops it less. The
third one even less. And remember that power factor correction only
decreases the imaginary current.
The real current varies with the load. The imaginary current does not
vary with load. But for your case where you are current limited,
reducing the current when unloaded, will cut the heating of the
breaker and wires when you are not loading the output. And helps keep
the breaker from blowing. Anyway I played around with caps of a
couple of hours, and the guy used it for over twenty years ( But only
used the sander maybe every ten days, it was not 8 hours a day 5 days
a week ).

One thing to remember about RPC is that they are only generating the
current and voltage for the third leg. So if you can get two thirds
of the power out of a three phase motor running it on single phase
power, you only need to generate one third of what a three phase
generator would have to generate.

Dan


Old Nick wrote in message . ..

Hehe! You can't "disagree" with somebody who has no idea what they are
talking about! GG


- the emphasis was on capital outlay. My limit is power available.
- there was frequent qualification of claims about capacitors and
tweaking and people who had wonderful success with a given load. Very
little about this vs a nice expensive "sedate" 3PH generator setup, or
true 3PH power.
- SORRY. There was one about getting 3PH power on. At this stage,
short of some sort of "community action" group, that's out of the
question.
- I am one of those wacko individualistic socialists....BUM! G


I got the definite impression that even under varying loads, the
efficiency was very high. You, Dan, are correct.

So now I have apocryphal statements that these things are great, and
"actual" figures from people trying to sell them to me GG. Bugger!

However, I have to admit that if the claims for a well-tuned RPC are
50% out, the efficiency is still above a belt-driven motor-gen setup.

I have to admit that some of my caution here is "free lunch"
stuff.....sounds too good etc.