Re: Dessalator shuts down for no apparent reason - CAT Pump Modification for less than 160 liters

Paul Dowd <paul.dowd@...>

Hi Arno,

Ok, I have found the problem: it was the TDS sensor connections that were corroded so it was shutting down because it thought the water quality was bad. However, what confused me is that I thought the red alarm light should go on in this case but it does not. The other thing that confused me was that after you suggested it was the motor thermal cut-out I checked the temperature of the motor and it was too hot to touch, but it now seems that was just because the generator was running. Then when I tries the 240V motor that also seemed very hot, but in that occasion it stopped because the pulley wheel bearing was not holding.

After cleaning the TDS connections and changing the pulley wheel it has now been working fine for an hour with the generator running. I am now getting the old pulley wheel welded so it can still be used but without the other side connected. I paid €300 for it and it lasted only a year!

I also checked the TDS and its 420ppm and I believe less than 500 is ok.

About belt tightness, they can be tightened by sliding the motor on its mounting.

In reply to Bill's request about the CAT pump, when my last one gave up I got a used CAT 277 but the 24V breaker kept tripping. I asked Dessalator and they said you cannot use the this one as it will burn out the motor. That's when I ordered one from Dessalator, and they sent me a CAT 237. My old one had the centre piston removed and blocked off. I don’t know if the new one is the same and I'm not about to take it apart to find out. I note that BHP pumps sells a CAT 237 for USD1113 whereas I paid Dessalator EUR1300 = USD1450. I note some differences in the spec between the 277 and 237, but I still don’t know if the blocked centre piston is a standard feature or a Dessalator modification.

S/Y Ya Fohi - Amel 54 #98

-----Original Message-----
From: <> On Behalf Of Arno Luijten
Sent: 03 April 2019 12:56
Subject: Re: [AmelYachtOwners] Dessalator shuts down for no apparent reason - CAT Pump Modification for less than 160 liters

Hi Paul,

When I took apart my watermaker last week I saw no way to tighten the belts. So over tightening the belts seems unlikely unless you have replace them with shorter ones.
It seems like your pump is taking more power than expected to rotate. Did something change about the pump?
I did replace the oil in mine (using standard 15W40 motor oil as prescribed). There is a small indicator that tells you about the oil level.
Did you take any of the single direction pulleys off? Did you put them back on in the correct way?
Also you may have introduced a blockage in the path after the pump. Does it run smoothly when you take off the HP hose from the mebranes?

Just some suggestions to help determine what is wrong…


Arno Luijten
SV Luna

Join to automatically receive all group messages.