Re: [Amel Yacht Owners] Capacitors for 160 AC Dessalator

Mohammad Shirloo

When we first got on board that is what we did. We dialed back the pressure to remain at 150l/hr or less. However, when we had to replace the black box controller on the HP pump, I had several in depth discussions with Martin at Dessalator to better understand the process and the systems. Martin stated that it is perfectly safe to run the HP pump on the high side of the green of the HP pressure gauge just shy of the redline. He said you could run the system in this configuration 24x7x365 without any issues or harm to the system.
So we have been doing this for the past 2 years. The output of the water maker will depend, to a large extent, on the water temperature. The higher the temperature the higher the output. Ours ranges between 145 to 175 l/hr. Martin mentioned that the rating of 150l/hr was placed on the system to make sure that it would produce that amount in the most adverse conditions.
Most of my information is from Martin and have not done much research on the matter. However, I have found Martin to be very knowledgeable.
Mohammad Shirloo
323-633-2222 Cell
310-644-0908 Fax

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Monday, June 18, 2018 11:32 AM
To: amelyachtowners@...
Subject: Re: [Amel Yacht Owners] Capacitors for 160 AC Dessalator


Gary & Mohammad,

The Dessalator D150, later named the D160 went through lots of changes, with the membranes being about the only part that remainded the about the same in all models. I said about the same because when Dessalator made the D150, each of the two 25x40 membranes was rated at 75 liters per hour at pressure. Filmtech changed manufacturing of this membrane, increasing output to 80 liters and Dessalator renamed the D150 to D160. 

BTW, some owners produce more than the rated numbers. You should not. Dial back the pressure knob so that output is correct for your membranes. Too much output and/or too much pressure will shorten membrane life. 


CW Bill Rouse
Admiral, Texas Navy
Commander Emeritus
Amel School
720 Winnie St
Galveston Island, TX 77550
+1(832) 380-4970

On Sun, Jun 17, 2018, 23:39 amelliahona <no_reply@...> wrote:

Mohammad & Aty:  

I don't know if we have the same motor for the HP Pump on the 160 l/hr Dessalator pump but I have noted your two different capacitors as opposed to the two 30 uf capacitors on mine.  Two 30 uf capacitors wired in PARALLEL yield a total capacitance of 60 uf.  

A 70 uf and a 180 uf capacitor wired in SERIES yields a capacitance of 50.4 uf, whereas if they were wired in PARALLEL that would yield a capacitance of 250 uf.  I am guessing yours are wired in series.

I am wondering if perhaps the manufacturer changed how these are wired (economics of capacitors supply or they were changed as a repair along the way or perhaps some more obscure reason??).  The run capacitor sizing is a matter of trial and error in most cases to yield the greatest efficiency of the motor (i.e. the lowest running temperature).  If you have nothing better to do, I would be intereste d if you could verify how yours are wired.

All the best, 

Gary S. Silver
s/v Liahona
Amel SM 2000 #335
Puerto Rico

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