Karl Townsend wrote:
My apple water bin dump uses a .5 horse 3 phase 220 VAC motor attached by
pulleys and belt to an outboard motor prop in a tube to pump water. Maybe 1"
head at 100+ GPM. I just measured the current draw on this motor at 1.5 amp,
2.0 amp, and 2.2 amp with a clamp A-meter.

Its a 1725 RPM motor with 2.2 reduction to the prop, so the prop turns about
800. Its a NOISY operation. The prop cavitates and pulls air even with all
the deflectors I can install to stop the vortex. (I've only lived with it
since 1988)
I really doubt you can make an outboard motor prop cavitate with a 1/2
Hp drive. It takes real HP input to the prop to do that. My guess is
it is just sucking air due to turbulence, I don't know what sort of
deflectors you are using, maybe some screens one inside the other would
stop the rotation. Making the intake the largest diameter you can would
help the air to not be trapped in the water.

Jon