by Wow! It really works!
I have been using a 7.5hp idler motor with just capacitor start for
several years and knew that the legs were not evenly balanced, but never
had any problem running my equipment.
The other day, I powered up a new hydraulic pump on a shop press, using
a 1.5hp single phase motor and it stalled the motor. "Well", says I,
"I've got a 5hp 3ph motor that I can use. No problem". After making the
mounting mod's, I fired it up, using the rotary converter, and would you
believe, it stalled the motor at just slightly higher pressure than the
1.5hp?
I dug out all of the 3ph stuff that has been floating around on the NG,
including info by Fitch, Hanrahan, Carlson, plus a lot of miscellaneous
stuff from all over. Went over to RA Enterprises in San Jose, dug
through their capacitor bins, and came up with an arm load of the darn
things for $25.00, plus a brand new 3ph motor contactor rated for 30hp
with 24vac/dc coil for $15.00. BTW, there are several more of these over
there, made by Fuji, still in the box with all hardware.
Hooked everything up and after first making the mistake of doing it in
series rather than parallel, got the unit up and running. Checked the
motor leads before adding the capacitors, and showed 10.5 on one, 10.0
on another and .8 on the manufactured leg. After adding the capacitors,
evenly matched on each side, I got readings of 7.5, 6.0, and 4.0
respectively. Finally, it took 40mf more on one leg to get the final
readings of: 6.0, 6.0, 5.5.
Probably the most interesting thing was the major decrease in amperage
from before the addition. Another was just how simple the entire thing
was. It simply took recognising the necessity and then doing it.
Thanks to all who have provided so much useful information on this and
other subjects.
Lee