Which Watermaker To Choose

[goboatingnow]

Inverter powered -- be sure you fully understand just how much locked rotor current your motor will command during the start. I had to build a surge control for my 2HP single phase motor to prevent immediate tripping on a standard 20 ampere breaker normally used in a home AC load center. I did not bother to research the trip curve.

why would you have a excessive locked rotor in a SWRO. ( as in no more then starting a coventional AC motor I mean) you always start with the pressure valve open. Sure you have the standard peak AC current, but most invertors can handle quite a peak current and you need to pick your breaker according , ie trip time

I should say that some cheap Invertors do have trouble starting AC motors. (6-8 times running amps in some cases)

Dave

[rover88]

Researching what watermaker to choose it's not long before you get overwhelmed by too much information - some of it total hype or downright bull.

I took a gamble on an old Spectra 308C at a reasonable price (time will tell just how reasonable) knowing full well I would need to have the Clark pump rebuilt simply because of its age and the membrane replaced, as well as buying lots of fittings, valves and prefilters. My gamble is that I will end up with a Spectra for less than the cost of a new Katadyn 40e.

I highly recommend listening to Tellie on this issue. He has been a tremendous help to me over the phone and via email and knows his stuff when it comes to watermakers. With his help I hope to get the unit ready to cruise next fall without blowing the cruising budget.

[foggysail]

Originally Posted by goboatingnow

why would you have a excessive locked rotor in a SWRO. ( as in no more then starting a coventional AC motor I mean) you always start with the pressure valve open. Sure you have the standard peak AC current, but most invertors can handle quite a peak current and you need to pick your breaker according , ie trip time

I should say that some cheap Invertors do have trouble starting AC motors. (6-8 times running amps in some cases)

Dave

There are two considerations to inrush (yeah, I know you know ) problems with no concern for the motor's application. The first in my opinion and the most important is the locked rotor which is the inrush when the rotor/armature is at rest. It may only be for a few milliseconds but there is no back emf occurring at that time. So the limiting factor is basically the motor's inductance which dominates over the motor's DC resistance.

The higher the HP, the greater the locked rotor current. My particular 2HP motor's specification has that current listed at 150 amperes when operated at 120vac, 60 Hz. There are commercial devices both active and passive sold to protect against this condition but $$$ was in my case greater than the motor's cost. The easiest solution for me was to take advantage of the 240 vac winding.... which has greater XL. I start the motor on this winding via some relays. After 15 or so seconds the relays switch the operation back to the 120vac winding for normal operation.

The second problem dealing with starting is having the motor start while under load which just adds to the locked rotor current. My controller (18F4550) times out the load during initial start and unloads the system by activating a high pressure solenoid valve that to minimize the system's start pressure.

Sure, if I had a 1HP motor I might be able to get by without worrying over the locked rotor condition but I don't. My pump is rated for 3.25 gallons/minute at whatever pressure up to its advertised rating.... I think its 2500psi. Now of course without going through the numbers, that would require a substantial amount of power where HP=(flow rate in gal/minute)(PSI)/1465<--- or in that neighborhood.

Baldor and most quality motors provide formula for inrush along with a quality factor needed to do the calculation.

Now getting back to inverters--- there are many factors that need consideration for operation well beyond there design. But before the power fets go belly up most likely the output voltage will just sag and again, it depends on how the inverter's protection is incorporated. The one I currently have for my fridge (a Xantrex 1KW true sine) just trips the internal overcurrent protection circuits if I overload it. I do believe the inrush could be substantially less using an inverter because of its lack of being able to supply that inrush be it due to the battery/wiring combo or the inverter's internal capability.

Foggy

[Pelagic]

Great Post Foggy and you articulated EXACTLY my concerns and why I am comparing:the ECHOTec 780-AML-2 AND the... 24v DC ECHOTec 780-DML-2. as my replacement system.

In my power generation application, I have a 24v shaft generator and large alternator off the main, so I have the opportunity to not always depend on my AC Gen to make water or charge batteries.

ECHOTec. Marine Watermakers*- DC Watermakers for Yachts*12 or 24 Volt*(Modular)

I will contact ECHOTec to find out if they use a Brush or Brushless Type 24v DC Motor and if Brush type, what maintenance schedule they recommend on the brushes?

Hopefully they will join in this discussion!

I remember somewhere they spoke about option of using a soft start if invertor was marginal.
If my calculation is correct my 24v Victron Multiplus 3000 watt will only produce 12.5 amps, so too close to depend on given Foggy’s explanation

The highly power efficient ECHOTec small generator/inverter series can be started by small to medium sized generators or inverters and leave ample power for other equipment when running. The system 780-AML-2, e.g. with a production of 31 GPH draws only 8.4 amp/h at 115 VAC. Therefore, even small generators/inverters will handle the low AC draw of the optional boost pump.


so it boils down to maximizing power generation operation vs. DC motor maintenance for me

[foggysail]

Pelagic--

I don't understand Echotec's literature claiming only 8.4 amperes are required for a 32 gallons/hour system. Yes, I did read where they claim 32 gallons product/hour which is fine. It most likely will be higher depending on the water temperature. ARE THEY USING A CLARK PUMP? If so, it probably makes sense, if not----

The quick analysis below is why I question the low AC input current:

First, the expected product is only around 15% of the water filtered through the membrane. Before you cast that estimate in stone, all the different factors regarding pressure, temperature and such should be ran through ROSA. But going ahead with 15% means the high pressure raw water in gallons/hour are = 32/.15 = 213/hour or about 3.5 gallons/minute.

HP= (flow rate/minute X pressure)/1460 = 3.5X800/1460 = 1.9HP

1HP = 746 watts so the system after surges will require 1.9 X 746 = 1417 watts. Because motors operate around 85% efficiency the wattage is nearer to 1417/.85 = 1667 and this ignores reactive power. The steady state line current should be around 1667/120 = 13.9 amperes.

And again, you need ROSA for a better analysis of the actual system pressure for particular conditions. Maybe Echotec can explain something I overlooked.

[Pelagic]

Thanks Foggy
Have sent them an Invitation to join this discussion, so hopefully we can all make an informed decision.

Also sent them this list of questions:
AC or DC Motor Questions/Concerns:
1. Confirm you do no supply a 230v/50hz Motor for 780-AML-2?
2. Then AC option is 960 - AML - 2S. (what does 2S signify??)
3. Will my new Invertor: 1 x 24v Victron Multiplus 3000 watt be easily able to handle start up loads for 960?

4. Is a DC motor driving same pump, inherently less efficient?
5. Do you use a Brush or Brushless Type 24v DC Motor?
6. If Brush type, what maintenance schedule do you recommend on the brushes?

[bouncingyellow]

I am looking at purchasing an echotec 260 DML-1, is there any problems with them that users know of, or is there any reverse boozemosis machines that convert salt water directly into beer, cheers.

[ka4wja]

Hello to all,
I hope you all don't mind if I actually address the main topic here (and the original poster's questions)....
(and, my apologies up front, to rover88, as there will be a LOT of info for you in this post, hopefully not so much that it causes "information overload" ....and I hope you can print it out and save it for your reference...)

First a few personal facts / disclosures up front....and some important info that may be overlooked.....and then some opinion...

Disclosure #1 - I think I've read the whole thread.....I may have missed a few words here or there, but if I did it wasn't more than a few words!!!


Disclosure #2 - I started cruising in the mid 1960's (as a kid), and over the years (cruising on/off, doing long voyaging, working on boats and living/cruising on-board my own, as well as majoring in physics and running my own electronics firm on-shore for almost 30 years now), I've seen a lot...(Like Rich and Tellie, I'm certainly NOT an "expert", but I seen/experienced a lot!)


Disclosure #3 - My first experience with a RO watermaker was in the 1970's......it was a 110vac powered unit (Sea Recovery, I think???, I'm not sure...it was installed by the previous owner, at the time of build....so we inherited it...), powered by a 12.5KW Westerbeake genset....
Keeping that beast running properly wasn't an easy task....made more difficult by my lack of understanding of exactly what was necessary (as there was no real "customer support" available at that time for us smaller users...)
After a while, we just gave up on it.....removed it from the boat, and gave it away to another long-range cruiser.....we never missed it, cruising the Bahamas, Carib, UK, the Med, etc...

I've had further experiences with RO watermakers over the years as well....
In the early 90's, a PUR 80 on a Tayana 37.....which worked surprising well, until the 12vdc motor died (burnt windings), in the southern Carib.....we sourced a new motor in Florida (pretty cheap) and put it in our carry-on bag on our next flight from the USA....it was still working when the boat was sold....

And, as a friendly fellow cruiser/sailor, I helped troubleshoot/repair a half-dozen others (on other peoples boats) over the years.....


Disclosure # 4 - I am one of those rare cruisers that CAN (and does) run his boat and his watermaker efficiently from solar and batteries, and NOT need diesel/gas/etc to suppliment my energy needs!!!!
(and understand that I'm not "out camping"....I enjoy a comfortable on-board life...)

Since 2006 I've had a Spectra Ventura MPC-5000 installed on my current boat.....
Over these past 6 years, she has seen > 12,000 miles offshore (incld two Atlantic crossings, multiple full-gales and a full tropical storm at sea), survived multiple direct hits from Cat 3 Hurricanes (at anchor), and has never stopped making all the water we needed....(and we use the typical 5-6 gal/person per day...)

She makes about 7gal/hr (6.9 to 7.4 gal/hr depending on water temp/salinity/voltage) on about 8 amps at 12.5vdc.....(she makes a tiny bit more at 13.8vdc, but not enough to worry about...)
And, I can make water anytime, day or night....without concern....
The "auto store" feature, allows me to keep my boat at anchor, or at a dock, etc. unattended for months at a time (the longest I've gone so far was 11 - 12 weeks, but I can go more), doing a fresh-water flush every few days to keep the system clean and free of growth....

But, eventhough my Spectra is a fully automatic unit (MPC), it WILL still work just fine and make the same clean fresh water in the MANUAL mode, WITHOUT the MPC controller (should the controller fail)....
This is accomplished by the flick of ONE toggle switch....and then I need to control one valve (the diverter valve) when water of low enough sailinty is being produced (either by testing, or "tasting", or by just letting it run for 3 minutes...)
And/or should the MPC controller be fine, but there be a failure of a "sailinty probe" etc. it is easy to "bypass" this function, and manually switch the diverter valve after the watermaker has started and you verify that it is making good quality water.....
I mention these points here in BOLD type, because these are often misunderstood points by even those who own a Spectra MPC watermaker!!!
(I've never needed to operate mine manually, but I DID do a manual operate test for an hour or so, at the dock a few years ago, just to make sure things work well....
And yes, I know that if you're going to be using a watermaker manually, why pay for all those fancy automatic features....I'm just pointing out that just because the Spectra MPC's are marketed as automatic units, that doesn't mean that they only work that way!!!)


{No BS....I met a guy in the Bahamas a coulpe years ago, whose salinity probe had failed, and he handn't made water since, while waiting 3 weeks for his part!! When I told him what to do, he looked at me like I was crazy, since the guy who sold/installed his unit never told him this.....(not sure who it was, but he was from the Chspk Bay area)
I offered to come on-board and fix him up, but ne declined....so, I'm not sure what he ended up doing.....}

My Spectra Ventura MPC-5000 is QUIET.....hardly notice she's running when sitting a few feet from it, in a quiet anchorage, and can't hear it at all when sailing as the noise from wind/sea is louder.....and can't hear it at all in the aft or forward cabins, even in a quiet anchorage....
Use rubber shock mounts to a secure bulkhead, etc. and you'll be amazed at how quiet she can be!!!

I have plenty of solar (520 watts, w/ MPPT controllers) and a large battery bank.....and love my big refrig/freezer, etc....
So, I do not skimp on creature comforts....
(But, I DO understand that I'm in the minority, as many find they do NOT have enough energy on-board to power their lives unless the burn fossil fuels....)
Full disclosure here....in addition to solar, I have a towed-water-generatir for those cloudy days on long passages....and have 120-amp Hehr Powerline alt. on my Yanmar engine....and I have a 6kw diesel genset (installed at the factory in 1999, and still has only 500 hours on it) and a 90-amp IOTA charger....(and have spare solar controllers, alternator/reg, charger, etc..) BUT....
But, I do NOT ever need to run an engine to make electrical energy (or make water) on-board.....expect to run Air Cond units or make some hot water (VERY rarely do either!)






Here is a link to an article I wrote in 2006 about my watermaker, the choices I made and why (and some photos I took during the installation of my watermaker)......and other links showing my solar array, etc....
Watermaker
Solar Panels
Nav Station
AIS Transponder
Annie Laurie Translant

And, here's a couple of photos of some of my sea berths, just a few feet from the watermaker, where I and crew can sleep when off-watch.....and while in a nice quiet anchorage you can hear the watermaker when laying on these bunks, when at sea the people in these berths cannot hear it!!!
I have to look at the panel at the Nav Station (or lift a floorboard) to verify that it's working!!
4705109
4707102



Disclosure #5 - While I do love my Spectra Ventura MPC-5000 watermaker, I have a real issue with Spectra's poor quality salinity probes!!!!
I have been thru 4 of these in just over six years!!!
(first one failed at the dock in Gibraltar, when the unit was less than a year old....and I never had one interfere with me making clean, fresh water....but it's the principle of the thing!!!)
I paid for one replacement, and my Spectra dealer/installer (Dick Murray) was so frustrated himself that he has paid for the others out of his pocket, and was supposed to see if Spectra would give 'em a few for free to use as spares for his good customers.....
To be clear this does NOT affect the waterakers performance at all, but it is something that was designed and marketed to work properly, and that I paid good money for, that does NOT live up to the reputation that Spectra has worked hard to get.....

So, my advice to Spectra is to FIX the problem with faulty/inferior salinity probes (even if costs an extra few dollars per unit)!!!!

And, my advice to those buying a Specyta, take a spare sailinty probe with ya'!!!!


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~



Okay, now that I've disclosed some of my background and experiences....
Here is some advice/recommendations that I sent out to a friend a few weeks ago, regarding watermakers, etc....
And, yes it is filled with opinion.....
But, one underlying fact (which was also posted earlier in this thread, by Rich, I think!) is that what works for one boat/one appliaction, does NOT work for all!!!!

~~~

J.
Watermakers do not illicit the same type of heated discussion that anchors do, however there are variables which you should be aware of before making your decision.....

To be clear, a watermaker is almost always a desire (luxury), not a
necessity....
(I have a Spectra, see below for details...)
And, whether your desire is large enough to pry open your wallet, depends on many factors....and please understand that the "cost" is not just the $$$$ you spend on the watermaker, but also the energy you use to run it, and any complexity it adds to your cruising lifestyle.....
If you choose correctly (and the installation is done right), there can be
few energy costs to you, AND actually a reduction in complexity to your
cruising lifestyle!!!!
(although, some have screwed-up on choice/installation and have had serious energy costs and added complexity to their on-board lives...)


1) First off, the type, manufacturer, and size of watermaker for YOU should be based on YOUR application, YOUR needs, and YOUR desires......
And, here are some things that might help you decide....


2) While most will say that watermaker choice is just "how much water do
you need to make" and "how much money do you wish to spend".....
There are actually a few criteria that are MUCH more important.....


3) Undersatnd that a watermaker is just an energy transfer device....it
takes in energy (whether 12vdc, 110vac, etc.) and it outputs energy / fresh, clean water.....
HOW you generate and store this input energy, and how MUCH of this you can generate and store (combined with your specific sailing/cruising plans), is the primary determiner of what type/size of watermaker you can install....(or whether you should buy/install a watermaker at all...)

a) How much (and what type) energy generation and storage do have
on-board????
(solar, wind, water, diesel genset, Yanmar alt. etc....large battery bank,
etc...)
And, what are your energy use / generation plans???

b) What are you sailing, cruising, voyaging plans????
(do you need a LOT of water everyday and are you able to replenish the
energy needed to make this water. easily, etc.)


4) Most cruising sailors will tell you that there are two things they never
hear from their fellow cruising sailors:
a) I have too much electrical energy on-board...
b) I have too much fresh water on-board...
BUT....
But, this does not mean you must have unlimited energy or unlimited water capacity/watermaker capacity....rather it means that your on-board capacity/generation (fuel/electrical/water/etc.) should match your application / match your needs and desires!!!!



5) While I'm a fan of alternative energy, and much prefer the quiet of
solar over the noise and odor of diesels, there are others who run an engine and/or genset EVERY day (some for 4+ hours each day), and for them a high-output watermaker allowing them to make lots of water quickly is an okay choice, as long as they use enough water to allow use of the watermaker ever 3 - 5 days.....(Watermakers like to be used....the ones that are used regularly last a long time.....those that only get used occassionaly, are typically those with problems....)

The flip-side of the guys who burn diesel every day, are the guys like me
who enjoy the freedom (and peace 'n quiet) that alternative energy
gives....and I can sit for days at an anchorage with an ice cold
frig/freezer, making plenty of fresh water, etc. or even leave the boat for
a week or two (or longer) and have no worries about things on-board needing my attention....

Now, where you fit on this continuum, I don't know....and you may wish to take a closer look at your specific application / desires, combined with
your on-board energy generation/storage plan, in order to see exactly where you fit on this sliding scale....
But, here is some "generic" advice:

a) If your cruising plans will put you in areas where fresh water is a rare
commodity, etc. then a watermaker might be a nice addition....
b) If you desire a bit more freedom on-board and when on shoreside
excursions, etc. then a fully automatic watermaker would be a great
choice....(such as Spectra MPC units...)
c) If you desire to be energy independent, a high-efficiency watermaker
(such as Spectra, etc.) is a good choice...and a smaller unit which uses
less current, over a longer period of time is a perfect choice for boats run
primarily on solar generation (or solar/wind/water power generation)....
d) If you already run an engine and/or genset every day for a few hours
(such as for refrigeration and/or battery charging), then a larger and/or
less-efficient (less costly) watermaker might be a less costly choice....

(For more detailed advice, I'd need to know more of your plans and how your energy system is set-up...)


6) Just to show you that I'm not a "green fanatic", in addition to my 520
watt solar array, and towed-water-generator, I have a 120-amp alternator on my Yanmar 4JH2-HTE, and a 90-amp smart charger run from either my 6kw Fischer-Panda or shore power.....

And, here are the details of my watermaker....
I, myself, installed a Spectra Ventura MPC-5000 (about 6 years and >12,000 offshore miles ago), and have been VERY happy with it....and this (combined with a large solar array) allows me to make all the water we need, AND still be completely energy independent (not needing any diesel fuel, etc. to make water, charge batteries, etc.).....
It is very quiet...can't be heard over the sounds of wind/waves/etc....nor
even in the aft or forward cabins in a nice quiet anchorage....but you can
hear it slightly, in the main salon (under which it is mounted) if making
water in a quiet anchorage.....
It's completely automatic (which makes it a dream to own and use), but can be used in "manual mode" should the automatic functions fail, or even if the entire control panel should fail, you can still make water in the "manual mode" with the flick of one toggle switch....(which I've never needed to do...)
I make about 7.4 - 7.5 gals/hr in tropical waters (and about 6.9 gal.hr in
colder waters) using about 8 amps from 12vdc....night or day, rain or shine, at sea or at anchor.....
With 215 gal water capacity on-board (in 5 tanks), I will usually make water every few days/as needed, for about 4 - 5 hours, as needed....

I wrote an article about my choice, w/ photos of the installation
process....(and as my Catalina 470 is similar in size/layout to your H46, it
might be quite useful...)
Have a look....(along with details/photos of solar array, etc.)
http://www.c470.jerodisys.com/470pix/47061.htm

http://www.c470.jerodisys.com/470pix/47004.htm
http://www.c470.jerodisys.com/470pix/47074.htm

~~~

And, a follow-up message with some further details....


I've written quite a bit about watermakers over the years.....and there are
a few new things that I've learned over the past few years that I can pass on.....
But first, please read over my article on watermakers, choices, and
installation (including photos of my Spectra Ventura MPC-5000 install), and of my energy system / solar panels / etc. so that you'll understand what I'm going to highlight below...

http://www.c470.jerodisys.com/470pix/47061.htm

http://www.c470.jerodisys.com/470pix/47004.htm

http://www.c470.jerodisys.com/470pix/47145.htm

http://www.c470.jerodisys.com/470pix/47137.htm



1) Once you've made the decision that a watermaker is for you / that you
need or desire one.......then comes the tough job of deciding which one,
what size, how to power it, and how/where to install it......

These questions are not stand-alone questions, and they actually should be taken and discussed together, as the answer to one WILL affect the
others......


2) My observations with a watermaker......

a) I'm a rare bird, in that I can make as much water as I need (typically
for 3 - 4 adults, taking showers, etc....and not being too miserly with
water), all from solar-charged battery power.....
I've observed that many who install 12vdc watermakers, find the power draw from them to be too much for their energy system to handle, and they end-up running the watermaker while running their engine, whether for propulsion and/or for battery charging.....with some ending-up running a genset (Honda, Fischer Panda, etc.) for battery charging and to supplement the energy for watermaking......

{I'm SO glad I've got a large solar array, as this not only improves my
range under power (as I do not need to burn diesel to charge batteries), but also gives me the freedom to sail/voyage/cruise where and when I wish and have plenty of fresh water, without being tied to a fuel supply.....}

I'm not saying that all of their battery banks are too small (although some
are), but that they do not have enough "energy capacity", which means that they cannot replace the energy to the batteries that they use, without burning some fossil fuels.....
And, some even have way too small wiring run to the watermaker.......this
cause excessive voltage drop, which causes the watermaker to draw more
current (bad) and produce less water (less GPH).....

This reinforces the concept of everything needs to work together, in order
to work optimally......
If you choose a 12vdc watermaker (which is almost a given these days), you need to make sure that you have the energy to run it......
Whether that energy comes from solar, wind, diesel, or gasoline (or a combination of these)......you've got to have some reliable way of providing enough energy on-board.....

The farther you voyage, and the longer you stay away from "civilization",
the more important "renewable" / "green" energy becomes (not just for the
$$$$).....remember, if you're spending the $$$$ for a watermaker, you're
obviously hoping to be away from civilization for a while, and the last
thing on your mind should be "where can I sail to, so that I'm close enough to buy diesel or gas???"
But rather you should be thinking "where can we go to get away from it
all???"

So, deciding on watermaker size SHOULD always take into account how are you going to power it.....and while the guys selling them will usually just tell you the current draw and GPH produced, there is much more to powering a watermaker in the real world than just knowing how many amps it draws and how many gallons you can make....



b) Install bigger wire than you think you should.......spend the few extra
dollars, it WILL pay off in the long run.....
I know it's overkill, but even for my 7.5 - 8 amp draw and fairly short
length (~ 8'), I used 8 ga......and I have no excess voltage drop, and my
Spectra produces the spec'd output (or higher!) easily on battery/solar
power.....



c) Install it where you can get at it.....to maintain it and service
it.......
Especially where you install the pre-filters as they WILL need to be changed / cleaned regularly, and you WILL spill some raw water when you do this, so make sure that wherever you have them can get wet!!!!



d) Although many find making water to be a "daytime" project (better
battery voltage from solar is one reason), if you're on a passage, there may be someone off watch that is sleeping, so be aware of that the feed pumps are not silent, and installing the entire watermaker (especially the feed pumps) with shock-mounts is important.....if not, using the watermaker may be an issue for a light-sleeper.....



e) The adage that watermakers need to be used is true......even if you
don't "need" the water, make sure that they do not sit unused for more than 7 - 10 days in the tropics (and no more than 2 weeks in colder climates)....5 days between uses / flushes is the typical factory default...
Having a unit with an automatic flush cycle means that you are NOT tied to the boat all the time.....and just need to make sure that you have enough water on-board to do flushes for the time that you're gone.....although, if you're in an area without oil in the raw water, you can even use raw water to do flushes......and the Spectra unit I have (the Ventura MPC-5000) will do fresh water flushes just fine (and either tank #2 or #3 will give me 2 - 3 months of unattended flushes), but should the fresh water supply run out it will continue to flush, with raw water (assuming the sea cock is open)......

While some marketing guys will tell you that you should always flush with
fresh water (and it's a good idea), if you use the watermaker every 3 - 7
days, and leave raw water in the membrane, it will still work just fine for
years.....just make sure that you DO use it regularly.....




f) Understand that your water use will increase after installing a
watermaker......it a luxury you get used to quickly!!!



g) Make certain that you know how to use, program, and maintain the
unit......In the case of Spectra, I've found many owners who were not aware that the unit can very easily (with the flick of one toggle switch) be operated completely manually (w/o any control panel at all), should the control panel fail, or you need to make water and there is an issue with a sensor, etc....

If you have an automatic unit, understanding the programming will make you love it!!!!
If you fail to understand it, you'll probably hate it!!!!



h) Have it installed by a trained professional, who has ACTUALLY done
installs of this specific watermaker before, and ask for references......(talk to the others who he's installed watermakers for!!!!)
The installation is really not a big deal, but the commissioning,
programming, and tutorial assistance you'll get will be worth the $$$ spent
for the professional!!!!!
(the plumbing and electrical stuff is easy, but "knowing" how and why the
thing works and how/why to make it do the things you desire are really what you're paying the professional for, so be absolutely sure he is aware of what you need / desire, before you sign a check!!!)



Okay the list of do's and don'ts goes on and on......so not sure where to
stop (more later if you need)
You may take note that I didn't do any recommending of what size (GPH), nor what brand (I really like Spectra and Cruiser Water and Power), as those are the easy answers......the hard answers are decided by yourself, using the info above and in my articles.....


Further info:::

a) Please have a look at a thread on the SSCA Disc Board regarding
watermakers, and the problems some have had powering them....
http://forum.ssca.org/phpBB3/viewtopic.php?f=4&t=10706
http://forum.ssca.org/phpBB3/viewtopic.php?f=4&t=10706&start=15


b) And, speaking of the SSCA, please be sure to read the SSCA Equipment
Survey, as there is a whole section on watermakers, and there are many fine comments on watermakers......
http://ssca.org/cgi-bin/pagegen.pl?pg=home&title=Home
http://ssca.org/survey/SevenSeasEquipmentSurvey.htm



c) And, another SSCA thread, with some experienced and learned advice....
http://forum.ssca.org/phpBB3/viewtopic.php?f=4&t=11932

Here's a quote from that thread....

"....As bad as it emotionally sounds, running a watermaker in a harbor isn't
going to damage the RO Membranes UNLESS there is heavy oil/diesel in the water. Since Fuel Oils floats on the water and the ships through hulls
should be low enough on the hull pulling in oils shouldn't be a worry. Sure
your prefilters will take a hit in filtering out the sediments and
biological growths, but at $5-$7ea they should be viewed as a sacrificial
component of the watermaker to protect the more expensive $187 RO
Membrane(s).
People install their watermakers in Marinas as a fact of life, so what I
recommend for people in an "ugly water" harbor or marina setting that want to test run their watermaker is to put in one or two 5 micron pre-filter elements (some systems have 2 prefilters while others have one) and then run the watermaker with the intention of removing the pre-filters and tossing them out after your test run. Then perform a fresh water flush of the system and for those really worried, sanitize your watermaker with your manufacturers' recommended pickling/sanitizing reagent. Since the
pre-filters are going to trap the "uglies" discarding them will keep the
harbor uglies form doing what they do in pre-filter elements: reproducing,
growing exponentially, and then dying and rotting creating the common
"rotten egg" sulfur smell. Sanitizing the system will kill anything that was
able to slip by the discarded pre-filters....."

I hope the above adds something to the assembled wisdom.....
And, while I do understand that I wrote quite a bit more than some will read, I thank those of you that do read it all!!


Fair winds...

John
s/v Annie Laurie

[Oceansailor]

Originally Posted by bouncingyellow

I am looking at purchasing an echotec 260 DML-1, is there any problems with them that users know of, or is there any reverse boozemosis machines that convert salt water directly into beer, cheers.

I have one and are very happy with it. No problems what so ever. Have been in service since 2005. Great company to work with.

Is there someone that are familiar with www.diywatermakers.com ?

They have ECO series that makes water only using 1.23A/Gallon (12V)

No energy recovery pump ?? Is that possible?

I wrote in an earlier post " more capacity is better"

My main reason for that is when i come out of the marina my tanks are empty. I want to be able to fill them in a reasonable time.
Unfortunatly my boat do not accept towers for solar panels. The tanks are close to 200 gallons.

[SV THIRD DAY]

[goboatingnow]

Good stuff, what I don't understand is how you can push the membrane " harder" with such a small motor. It suggest you are getting a 30 % recovery rate !!!


Dave

[Therapy]

Originally Posted by ka4wja

But, eventhough my Spectra is a fully automatic unit (MPC), it WILL still work just fine and make the same clean fresh water in the MANUAL mode, WITHOUT the MPC controller (should the controller fail)....
This is accomplished by the flick of ONE toggle switch....and then I need to control one valve (the diverter valve) when water of low enough sailinty is being produced (either by testing, or "tasting", or by just letting it run for 3 minutes...)
And/or should the MPC controller be fine, but there be a failure of a "sailinty probe" etc. it is easy to "bypass" this function, and manually switch the diverter valve after the watermaker has started and you verify that it is making good quality water.....


John
s/v Annie Laurie

John.

Lots of good advice/info

By the way, did you know that if your salinity probe goes you can go into your MPC unit and tell it to ignore it and then you can use the watermaker like before with the MPC controlling all the rest of the functions?

Our boat had 60 gal total capacity in two 30 gal tanks. We went through one tank every 2 1/2 - 3 days. That is 5 hours of run time not counting start up and flush after. I found that a long time (for me). I would go with more capacity next time.

My other issue was the water I was floating in clogged the filters a lot faster than I cared for. Having to go "away" for a whole day (there - 5hours of watermaking - and back) was no fun either. Though it could have been called a fishing trip I guess.

Maybe I just stopped in crappy-water places.

[wolfenzee]

Some of the quotes I have heard for how much people paid to have a fully automatic water maker profesionally installed (not even including the cost of powering it) far exceed what I paid for my entire boat.

[SV THIRD DAY]

Originally Posted by goboatingnow

Good stuff, what I don't understand is how you can push the membrane " harder" with such a small motor. It suggest you are getting a 30 % recovery rate !!!
Dave

"Push" maybe wasn't the best choice of words because it implies "force", which isn't true. We operate our systems at 800PSI. What I mean by "work them harder" is designing a system with a higher recovery rate.

Here are the actual flow numbers and Recovery rates for a dual RO 40" Membrane water maker using a 1.6GPM pump.

The 1.6GPM pump is 96GPH, so lets work in GPH for ease of following.

Membrane one produces 20GPH of product water with 96GPH of sea water flowing into the membrane, so the Recovery rate of Membrane one is:

First Membrane Recovery Rate = (20GPH/96GPH)*100 = 20.8%

Membrane two is only seeing 76GPH, since 20GPH was removed as fresh water by membrane one. So the recovery rate of the second RO Membrane would be:

Second Membrane Recovery Rate = (13GPH/76GPH)*100 = 17%

So back to what I mean about "working the membrane hard". If we wanted to esign a water maker with a recovery rate of 8% (and not work the membrane as hard), then we would need a huge amount of flow which would be unrealistic for a marine unit from a power and flow perspective. Or we would use a smaller surface area membrane to drop our product water production rate, so that less water went through the membrane and left as brine. Higher recovery rate water makers are common and take advantage of the realities of how water makers are operated on a boat. A lot of people confuse Dow's 8% recovery rate as a limit, which is not. The recovery rate issue is a sliding scale of membrane replacement cost coupled with the water maker flow production rate with other things like power requirements thrown in.

Originally Posted by wolfenzee

Some of the quotes I have heard for how much people paid to have a fully automatic water maker profesionally installed (not even including the cost of powering it) far exceed what I paid for my entire boat.

Amen Brother!
I've shared an anchorage with cruisers who spend more a month on marina's and their Boat payment than our family of FOUR spends for an entire month or Cruising Mexico! Money is relative and it's even better if you have a "Rich Relative"..ha ha ha


Rich
SV THIRD DAY
Currently Living Aboard in Port San Luis, CA
Awaiting my return to Mexico!

[goboatingnow]

Sorry if I'm being dense here. But for example Dow Filmtec state that the maximum recovery for Sw30 2.5 inch RO membranes is 15% and quite a bit lower at 800 psi. While I accept the 8% isn't a maximum, at a stated pressure the flux is a fixed number. ( for a given membrane size) ( within a fairly wide manufacturing tolerance) increasing the flow does not increase the % recovered , increasing the pressure does. But only to the point when the membrane stated limits aren't exceeded. No where can I see a 20 % recovery figure . I still cant see how at your stated operating pressure of 800 psi, you are getting that recovery.

This coupled with
13gph/76gph = 17%. Seems very odd. I see where the 76 comes from but the 13 seems to be picked along with the 20( in the previous equation) to magically arrive at the desired output.

Dave