Eletro magnetic clutch for watermaker pump

[a64pilot]

Be interesting to know if a pump pulls more than a very high amp alternator.
I'd be surprised if it did.


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[Cheechako]

Yeah, I don't think it will. The 100 amp alternator on the 3GM30 pulled it down more than the watermaker pump ever did.

[phorvati]

Originally Posted by Cheechako

I remodeled my 120V AC water maker into engine driven. It had a Cat pump I mounted on the engine. It was pretty easy to find a 12V clutch for the Cat pump. Is yours tapered shaft or straight shaft? Metric or inch shaft?
My original AC unit was 1.5 HP direct driven. It had 3 membranes and put out 25 GPH water.

As far as the clutch, I tried getting them at junkyards, but all auto AC units are tapered, where Cat pump shaft is straight. After years of searching for a used one on ebay I ended up buying a new Cat pump clutch for 220$. It was made to fit cat 290 and pumps with same shaft diameter. (0.65" or 16.5mm) Those clutches will rust very fast. Mine already looks used and abused and its been 2 seasons. I like the Cat 290 b/c even though its chromed brass, parts are cheap and used parts and pumps are readily available on ebay. This a one of the most popular carwash pumps. So i have spares. For DIY if you make a mistake that damages the pump, spares are available and even used pumps are cheap. For instance i cracked the outlet manifold one time, and another time vibrations were so large that one of the two bolts(they are zinc plated steel) holding the two manifolds busted.
So i feel like iv'e learned some things over the years and finally, last may after about 6 years of searching ebay I ran into a new (never used, but opened in a box) cat 331, and indeed it showed no sings of ever seeing any water. Ended up paying 350$ for it. Which was an amazing deal. They are usually 3k or so from distributors. So i plan to retrofit the mounts for Cat 331 which i hope is not that far off from 290.

[a64pilot]

I can pop a serpentine belt with a spring tensioned idler off faster than you can check the oil, seriously, no need for a clutch.
Or, use this method

https://www.youtube.com/watch?v=BQhfcdQf1QA