[Amel Yacht Owners] Dessalator Duo D60 Problems


Bill & Judy Rouse <yahoogroups@...>
 

Duane,

My guess is that you have a water supply problem...possibly a blockage anywhere between the CAT pump and outside the boat, a poor performing feed pump, or clogged prefilter. My guess is that the CAT starves for water (pressure down), then gets a burst of water (pressure up). When it gets this burst of water, the pressure momentarily exceeds the limit on the high pressure switch causing a shut-down.

This is just a guess based on what you have reported...I have never experienced this before.

Best,

CW Bill Rouse

Admiral, Texas Navy
Commander Emeritus
Amel School www.amelschool.com
720 Winnie St
Galveston Island, TX 77550
+1(832) 380-4970




On Tue, Jun 13, 2017 at 8:56 AM, sailor63109@... [amelyachtowners] <amelyachtowners@...> wrote:
 

The watermaker has been a bit troublesome.  The Duo D60 has both 230 volt AC and 24 volt DC motors that power a single CAT pump.  I removed the belt from the 230 volt AC motor so I could use a solid pulley wheel on the CAT pump.  I did this because I was having failures with the "one-way" (also called clutch bearings, sprague bearings or bendix bearings) bearings that let the idle motor free-wheel.


Now for the problem:  The water maker will run normally for 30 to 90 minutes, then it will shut itself off.  After it did this several times I watched it throughout the watermaking process and found that at first the needle in the pressure gauge was steady after adjusting to the middle of the green zone.  Shortly before it shuts itself down the needle begins to jump up and down indicating the pressure is increasing and decreasing.  The swings become more and more pronounced until it finally goes below the green zone and the automatic shutdown happens.  


I wondered if this was a low battery problem, but it doesn't seem to be.  This morning it happened at 30 minutes of run time and shut down at 24.84 volts (measured with no loads on the batteries for 5 minutes).  It also happens when I'm running the generator with a battery charger on and the watermaker on the 24 volt motor.


I'm wondering if this can be a CAT pump problem.  The hour meter only shows 680 hours and CAT pumps have the reputation of being pretty long lived.  The other symptom of the CAT pump being the problem is the propensity of those bearings to self destruct.  The ones I replaced the originals with met the same specs and yet they only lasted a dozen hours or so.  I've been told that the bearings used by Dessalator were some type of exceptionally tough bearing but the distributor disagrees with that.


Any t houghts?


Thanks in advance,

Duane

Wanderer, SM#477



karkauai
 

I have had similar problems on my D60 (not duo...no feed pump) that were related to air getting into the intake line.  Once it was a failed hose clamp on the line itself, and once a failed hose clamp on the A/C pump.  There was no leak obvious either time, but in the glass vial monitor on the Desallator control panel, bubbles could be seen intermittently.  The pressure would drop, then rebound high enough to cause the unit to shut down.  I guess the negative pressure from the pump on the intake side would somehow open the leak, which sealed itself when the pump was turned off.
Do you have the water quality/quantity attachment on your control panel?  If so, are bubbles seen in the glass vial where product water quantity is shown?

I'd have a look at all hoses and connections from the raw water manifold to engines, A/C pump, Desallator, Heads, and anything else that connects to it.

I am going to place shut off valves on all these hoses so I can isolate any equipment without shutting the thru-hull off for repairs on the fly.

Kent
SM 243
Kristy



From: "'Bill & Judy Rouse' yahoogroups@... [amelyachtowners]"
To: "amelyachtowners@..."
Sent: Tuesday, June 13, 2017 10:49 AM
Subject: Re: [Amel Yacht Owners] Dessalator Duo D60 Problems

 
Duane,

My guess is that you have a water supply problem...possibly a blockage anywhere between the CAT pump and outside the boat, a poor performing feed pump, or clogged prefilter. My guess is that the CAT starves for water (pressure down), then gets a burst of water (pressure up). When it gets this burst of water, the pressure momentarily exceeds the limit on the high pressure switch causing a shut-down.

This is just a guess based on what you have reported...I have never experienced this before.

Best,

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




On Tue, Jun 13, 2017 at 8:56 AM, sailor63109@... [amelyachtowners] <amelyachtowners@...> wrote:
 
The watermaker has been a bit troublesome.  The Duo D60 has both 230 volt AC and 24 volt DC motors that power a single CAT pump.  I removed the belt from the 230 volt AC motor so I could use a solid pulley wheel on the CAT pump.  I did this because I was having failures with the "one-way" (also called clutch bearings, sprague bearings or bendix bearings) bearings that let the idle motor free-wheel.

Now for the problem:  The water maker will run normally for 30 to 90 minutes, then it will shut itself off.  After it did this several times I watched it throughout the watermaking process and found that at first the needle in the pressure gauge was steady after adjusting to the middle of the green zone.  Shortly before it shuts itself down the needle begins to jump up and down indicating the pressure is increasing and decreasing.  The swings become more and more pronounced until it finally goes below the green zone and the automatic shutdown happens.  

I wondered if this was a low battery problem, but it doesn't seem to be.  This morning it happened at 30 minutes of run time and shut down at 24.84 volts (measured with no loads on the batteries for 5 minutes).  It also happens when I'm running the generator with a battery charger on and the watermaker on the 24 volt motor.

I'm wondering if this can be a CAT pump problem.  The hour meter only shows 680 hours and CAT pumps have the reputation of being pretty long lived.  The other symptom of the CAT pump being the problem is the propensity of those bearings to self destruct.  The ones I replaced the originals with met the same specs and yet they only lasted a dozen hours or so.  I've been told that the bearings used by Dessalator were some type of exceptionally tough bearing but the distributor disagrees with that.

Any t houghts?

Thanks in advance,
Duane
Wanderer, SM#477




Duane Siegfri
 

Thanks for the reply Bill.

I should have noted I washed the pre-filter thinking it could be a blockage and it still shuts down.  It's odd though, because sometimes it will run for two hours or more without a problem.

The pre-filters I use are washable, but maybe there's a limit to that.  I'll put a new one in and see if that helps.  Here in Lake Worth the water is pretty muddy, but I was having the problem in the Bahamas as well.

I don't have a feed pump, the CAT pump is plumbed directly to the pre-filter.

Duane


Bill & Judy Rouse <yahoogroups@...>
 

Duane,

I said, "possibly a blockage anywhere between the CAT pump and outside the boat, a poor performing feed pump, or clogged prefilter."

So, before I would declare a problem with the CAT pump (which is possible) I would check flow from outside the boat to the CAT. That includes sea cocks, filters, strainers, and hoses. I suspected a supply blockage and not an output blockage because you said that the pressure goes down, then up. Of course it could be a bad regulator valve, output blockage, or the CAT pump. But, based on what you said, it sure sounds like the high pressure switch is shutting the system OFF.

I was simply giving you my best guess and to check only one item doesn't really get either of us anywhere. If I were you, I would assume that the CAT pump and the high pressure switch are operating correctly and your problem is a flow problem.

Best,

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




On Tue, Jun 13, 2017 at 2:53 PM, sailor63109@... [amelyachtowners] <amelyachtowners@...> wrote:
 

Thanks for the reply Bill.


I should have noted I washed the pre-filter thinking it could be a blockage and it still shuts down.  It's odd though, because sometimes it will run for two hours or more without a problem.

The pre-filters I use are washable, but maybe there's a limit to that.  I'll put a new one in and see if that helps.  Here in Lake Worth the water is pretty muddy, but I was having the problem in the Bahamas as well.

I don't have a feed pump, the CAT pump is plumbed directly to the pre-filter.

Duane



Danny and Yvonne SIMMS
 

Hi Duane
I would never use my water maker in muddy water. Too much filth to strain out. If you do you should change the filters often.  Hope none of the filth is getting to your membranes.
Cheers
Danny
SM299
Ocean Pearl

Sent from my Vodafone Smart

On 13 Jun 2017 8:53 p.m., "sailor63109@... [amelyachtowners]" <amelyachtowners@...> wrote:
 

Thanks for the reply Bill.


I should have noted I washed the pre-filter thinking it could be a blockage and it still shuts down.  It's odd though, because sometimes it will run for two hours or more without a problem.

The pre-filters I use are washable, but maybe there's a limit to that.  I'll put a new one in and see if that helps.  Here in Lake Worth the water is pretty muddy, but I was having the problem in the Bahamas as well.

I don't have a feed pump, the CAT pump is plumbed directly to the pre-filter.

Duane


Bill & Judy Rouse <yahoogroups@...>
 

Duane,

Why are you using 30 micron? Dessalator specifies 5 Micron for the DUO60, and they state "has to be replaced either every two or three months, or according to the sea water purity."

Obviously, this 30 micron filter has allowed particles into the CAT pump that should not be there. And when you "clean" a washable filter, you will never get the small embedded stuff...only the big stuff.

I imagine that this could be part of your Dessalator shut-down mystery.

I suggest that all users follow Dessalator's specific instructions, unless they have an intimate knowledge of the system.

Best,

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




Danny and Yvonne SIMMS
 

Thanks for the reply Duane. Bit like my not using distilled water in my batteries. Anathema to some, but works for me. Certainly you would want to be on the ball servicing the pre filters. I am fortunate that I am in clean water  enough that I can avoid using the desalinater in dirty water.
Regards
Danny
SM 299
Ocean Pearl

Sent from my Vodafone Smart

On 20 Jun 2017 2:38 p.m., "sailor63109@... [amelyachtowners]" <amelyachtowners@...> wrote:
 

Danny,


I understand how you feel.

I have a 30 micron washable pre-filter before the pump.  30 microns is about 1/8" divided by 1000!  .Not much dirt is getting to the membranes.  If you have the washable prefilters you can make water anywhere you are.

I have a liveaboard friend who had his membranes for more than ten years and he made water wherever he was.  I met him in Brunswick GA and the river water here is pretty muddy and he continued to make water.

Duane


Duane Siegfri
 

Bill,

You're right, they are 5 micron filters.  I double checked just now to be sure.  Thanks for making the correction, I wouldn't want to lead someone astray.

Duane