I'm in the process of researching and designing a small RO desalinator
for my Sea Sprite 34. Have found Glenn's, GOB's and other DIY articles
to be good resources. However, my engine compartment will not easily
accommodate a CAT 277 sized engine driven pump. Also don't have room
(or $$) for a large built-in generator to deal with the startup
requirements of a 2HP electric motor. I already have a Honda eu2000
generator which, based on it's output, will be used to size the
smaller watermaker. With 2000W max and 1600W continuous on the eu2000,
it looks like the largest electric motor possible is a 3/4HP. A 1HP
may be possible with soft-start electronics, but I haven't been able to
find reliable information on the subject (even from Baldor). The 3/4HP
motor would directly drive a CAT pump model 2SF10SEEL (1 GPM, 100-1200
PSI, 1725 RPM). Fitted to a 2.5 x 14 membrane, it should provide 100GPD
(about 4GPH).

I'm still trying to find other ways to increase the system's capacity.
There are 3/4HP motors available that run at twice the RPM (3450),
which could be "geared down" with a pulley/belt to drive a larger
capacity CAT pump at the required 1750 RPM.

Using the eu2000 generator as a power source for watermaking has
obvious downsides: noise, long run times & low product output. There
are two of us, so our water usage would usually be small and our total
tankage is only 90 gallons. A couple questions to the group: do my
3/4HP system components and output assumptions look right and are there
any other options available for increasing the capacity of the
watermaker within the generator's power constraints?

Will