The Mighty CanDoAlot!

[s/v Jedi]

Originally Posted by ShaktisBoy

The unit is modular based on the Kubota EA330 diesel. The kit comes from Aquamarine in Washington state but there are a few others around doing similar in things. We installed the Generator section about 2 years ago with the hope of running the existing Air Conditioners on a 5KW pure sine wave industrial inverter. Because we are a catamaran we had an extremely long 0000 wire run back to the house bank which subjected us to some realities of electricity in that over long distance we suffered enough line loss that the DC generator putting out a constant 150 amps was unable to keep up with the demand required by the inverter 2 air conditioners and limited other AC loads. Compounding the problem was drag caused by simultaneous starting of the 2 AC units if the thermostats happens to pick the same instant to start. Even with soft start capacitors installed the locked rotor amps would trip the inverter circuit breaker. We could run 1 of the units all day and night cool our cabin or the salon but sadly that just wasn't enough for a boat this size when there was no wind here in August and more than myself and my wife aboard. After realizing we weren't getting what we wanted yet contacted Dan Forest of Aquamarine and he said he had successfully installed a automotive based unit in a monohull not to long before we called inquiring. He took our boat info and specced out the major components and sent them down to us. The rest was up to me to figure out like hose low and high pressure hose length, refrigerant and oil charge and routing of the ducting wiring and believe it or not the hardest part was getting a simple digital thermostat that runs on 12 volts that also incorporated a relay to stat the compressor. The system is raw water cooled before the heat exchanger which on a 95 plus degree day raises my normal operating temperature from 175 to almost 190 but that's still well within limits for the Kubota. I also need to correct a typo I made that states the Evaporator fan moves 850 CFM it's 650 CFM but still plenty to chill the boat right down. Some asked if I have to run CanDoAlot to cool the boat at the dock and the answer is no. We left the cruiseairs in place for shore power dockside cooling.

The Major components are as follows.
Compressor. Sanden SD73H13 model 7312 with v belt magnetic clutch
Evaporator. DanHard model 00942
High pressure pump not sure about the model but al out identical to the ones offered by many manufacturers including CruiseRoWater's pump who's system I really like by the way
Membrane is a WaveCyberAttachment 123997Attachment 123998 1000 psi vessel
The water maker control panel is custom made by Aquamarine inc. here are a few more pics of the project.
Attachment 123988
Attachment 123989Attachment 123990Attachment 123991Attachment 123992Attachment 123993Attachment 123994Attachment 123995Attachment 123996


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Shaktis let me tell you I am impressed not just with your install but also with the looks of your engine room with the insulation and cleanliness.

My posts here have not been to attack you; looking at your engine room I even think I probably like you... they were merely meant to correct some info that I know is wrong. I do that with posts from anybody, even my friends and now and then even in reply to my own posts when I find that I was wrong when writing it and nobody else noticed. The reason I do this is because I try to have info in threads where I am knowledgable with the subject, as correct as possible for readers that may not necessarily post themselves.

Please do not take my posts as ad hominem, because they really aren't. Hope you understand

[ShaktisBoy]

Ok Jedi time for a fact check.

First: Never in any of my post did I mention KW hours or claim that they were the same so please don't speak for me. What I said was I'm burning Less fuel and what I mean by that is simple. I run CanDoAlot less because I can charge my batteries faster, way faster than the northern lights ever could. See any number of articles on DC vs AC charging of batteries.

Second: I agreed with you 3 times about thermal dynamics and all things being equal X hp takes X fuel.

Third:

The northern lights at least in our installation had 2 X 110 legs. One on Side A and the other on Side B. On the electronics package above the Rotor/Stator assembly there are 2 push type 20 amp circuit breakers tied into a dual 25 amp main breaker. What I should have said was that while running both Air conditioners one on side A and the other on side B just by themselves used up almost 1/2 the available amps on each leg and that any additional loads that were present pushed up the amps right to the capacity of the push type circuit breakers on their respective side. On average we had approximately 35 amps of the available 50 amps or approximately 70% of total available between the 2 sides going anytime the Northern lights was running and some times if someone plugged in something else it was enough to overload the 2x25 main breaker. I also mentioned that the Northern Lights would sometimes run unloaded when the air conditioners cycled off. This had the unpleasant effect of sooting up the hull near the exhaust pipe and worse than that it caked up the mixing elbow with carbon requiring a tedious chore of removing the sound shield, draining he coolant, contorting oneself into position to reach the backside of the unit to get at the bolts holding on the mixing elbow on then cleaning it out with a wire brush and reversing the processes. That is no longer an issue.

Forth.

I never said I was a jet engine scientist. What I said was as part of my job description I teach Pratt and Whitney PT6A-66 and Pratt and Whitney PT6A-66B engines. In that capacity the curriculum spends quite allot of time on fuel burns specific to the aircraft I teach where we delve into subjects like max range power vs max endurance vs max cruise. Things like torque, ITT, density altitude, ISA temperatures both above and below standard have a great effect on the outcome of a flight.

As far as you calling BS I have thick skin and it doesn't really bother me. As a matter of fact I like a little adversity as it helps me stay sharp plus I already took some of the blame for not being specific enough where thermal dynamics is concerned. I also think there are a folks who have or may have wondered what the benefits might be on a DC generator option. For them I recommend a website found at zrd.com it's in my opinion hard to read but full of great information although the Author while extremely well versed on the subject can be annoying in his contempt for others who don't understand what he's trying to explain.

So in closing yes you are right X Hp requires X Fuel or BTUs to accomplish work.


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[44'cruisingcat]

Originally Posted by s/v Jedi

I am sorry but it is you comparing apples to oranges. When you load both units equally, say 5hp, then they consume the same amount of diesel fuel. It doesn't matter that the Northern Lights unit is bigger and heavier, which is relevant for it's longer lifespan, not for fuel consumption.

Except that the larger engine will consume more fuel to simply turn itself over. More moving parts, more mechanical drag, etc...

[s/v Jedi]

Okay, I made up the part about the Jet Engine scientist and also the FrankenGen name. I can't find it and it may be on another forum, but there was somebody else doing this and he named it FrankenGen. Ah, here it is: sv Abake: Frankengen Is Alive!

About DC generation: is it really a DC generator or is it an alternator with rectifying diodes? If it is the latter, then the losses of conversion from AC to DC are still there, in the form of heat dissipation. The AC generator does not have those losses (brushless as well) so that compensates for losses in the AC powered battery charger.

I have started our "Jedi" adventure with a boat that was almost 100% DC, with 1,800Ah house bank and a total of 475A @12V power generation from engine-mounted alternators. I still love that, but I also have learned to appreciate AC for the watermaker, the galley (no propane) etc. The main advantage is redundancy: I can run the watermaker from either the AC generator or the inverter, while feeding it with the big spinning alternators.

[ShaktisBoy]

It is in fact a rectified 240 continuous amp alternator. Yes there are losses due to heat but the efficiency comes from being able to dump a huge amount of power quickly into the batteries. The old generator took hours to charge through the inverter charger 90 minutes now from 50% S.O.C. To about 90%. The 900 AH Lifeline AGMs will accept way more than the Magnum Energy 2800Watt inverter/charger northern lights combo could provide.


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[s/v Jedi]

Originally Posted by ShaktisBoy

It is in fact a rectified 240 continuous amp alternator. Yes there are losses due to heat but the efficiency comes from being able to dump a huge amount of power quickly into the batteries. The old generator took hours to charge through the inverter charger 90 minutes now from 50% S.O.C. To about 90%. The 900 AH Lifeline AGMs will accept way more than the Magnum Energy 2800Watt inverter/charger northern lights combo could provide.

The 240A alternator is a good fit for the battery bank. Rule of thumb is 20% of the 20h Ah capacity, 0.2C, which comes to 180A acceptance rate. The alternator, even when it tones down a bit when hot, can provide that 0.2C.

In your old setup, the problem/bottleneck was the charger, not the genset. To get 0.2C performance, you would have needed two 100A chargers working in parallel, and those don't come cheap either. This shows how much better a well balanced system is.

[ShaktisBoy]

I know I could have spent the money to repair and put in another dictated charger or bought a used generator for less but I never I would have liked that option. I also needed to be a smaller of stature to be able to work on it. I needed to be prepared to spend a lot more money for the proprietary parts needed to keep it running and willing to accept that it took up almost the entire forward port locker which is really big by the way. Because of the smaller size of the new unit I can work on it easily and parts are available everywhere. The new unit takes less than half of that space and weighs 100s of pounds less . Before I could put maybe 2 scuba tanks and a pair of flippers in that space today I keep a full set of gear for 4 with room to spare. The spectra 150 5gph watermaker was removed from under the salon seat and the evaporator took up its old space so now the new 24 GPH watermaker resides in that outside locker along with the air conditioner and charger. Did I mention this is on a cat and weight is an issue?


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[a64pilot]

ShaktisBoy,
Mind posting a link to that sound proofing?

[rourkeh]

There are a lot of ways to approach the purchase of a new generator.
I bought a Northern Lights 8 KW 1800 rpm unit with 1,700 hrs , it was a perfect running take out from a larger yacht that needed a bigger unit. Cost $1,500. I removed all the ancillary equipment like starter, water pump, etc and painted and reconditioned the unit. Cost $2,000. Bought a new soundshield, Cost $1,500. I did all the labor and install myself. Now I have a generator that looks and runs like new for just over $5,000. I will take excellent care of it and due the maintenance religiously and I should get another 8,000 hours out of it. I also got the opportunity to buy an older unit that was manufactured in the early 1990's with no fancy computer boards or expensive cutting edge rubbish that will burn out in 5 minutes. Saved myself around $14,000 and got exactly what I wanted.

[a64pilot]

FWIW,
A smaller engine running at near it's max HP output will in fact burn less fuel than a larger engine making the same power at half it's rated output.
Using mechanical power directly to drive accessories is much more efficient than making electricity and using that electricity to run electric motors to drive accessories.

Every thing is a trade off, there are no perfect solutions. Here he gained three things that are important, lost weight, less fuel consumption, and gained more storage space.
Now which of those three things do we not all want?
I congratulate him on a job well done! I believe he deserves to brag a little, I would, there is great pride in doing something yourself, and having it work
This is no small feat, the AC alone is beyond most peoples capability, that stuff isn't as easy as you may think.

[s/v Jedi]

Originally Posted by a64pilot

FWIW,
A smaller engine running at near it's max HP output will in fact burn less fuel than a larger engine making the same power at half it's rated output.
Using mechanical power directly to drive accessories is much more efficient than making electricity and using that electricity to run electric motors to drive accessories.

About the fuel burn: of-course you are right, but this isn't how it works in reality. When you buy a genset then you buy one that you load up much higher than 50% under normal circumstances. When OP now starts FrankenGen with the batteries low, he needs to decide between watermaker or A/C (just an example) because with the big alternator working, there isn't enough hp to run all three, while the bigger genset would have done all three at the same time, saving run-time. Then there's the thing that the cost per kWh goes down the bigger the genset gets.

The main thing is that you must be able to load up the genset and this is something that many can't do. Running it at less than 50% load is bad for the genset and the wallet. At 50% most gensets have a sweet spot where they use less fuel per kWh than at lower and higher load. When I don't need much power but still need/want to run the genset then I also run my watermaker, A/C, waterheater etc. just to load it up to at least 50%.

About mechanical power: example: a belt driving a clutch with attached high pressure pump for a watermaker. This belt drive has much higher losses than a direct drive brushless AC generator attached to the diesel driveshaft. This means we get our AC power a bit "cheaper", but we now need an electric motor to spin the water pump. If we use 240V this runs more efficient than 110V and a 97% efficiency with a good 1-1.5hp motor is possible.

I agree that this is still more loss than spinning the high pressure pump with a belt. But then there is another belt spinning the alternator and another one spinning the A/C compressor (or all are on the same belt but then they add resistance losses to that belt even if their clutch is off). All those we don't have with the AC genset so their complete loss is avoided. This is the strength of just making one thing: you can do it more effective. Add that to the flexibility of AC power: a couple of wires to somewhere is much easier than a belt, plus you can have an alternate source like shore power or inverter power. It is going to be a toss which system wins. But it is clear that for the physical size the FrankenGen wins and also when comparing the investment. I think maybe the AC genset will win cost-wise when we take service and replacement cost in consideration because the slow turning 1,500 or 1,800 rpm diesel 3-cylinder is much more robust and has a longer lifespan than a 3,600 rpm 1-cylinder.

I would like the FrankenGen and have considered one. You can get a hydraulic pump for it so that you can run a couple of hydraulic hoses somewhere and hookup a hydraulic motor to spin things like watermaker, scuba compressor etc. I would still want an electric motor on my watermaker pump so that I can run that with either the FrankenGen or another source like the inverter. I need to be able to make water even when my genset dies.

[ShaktisBoy]

Originally Posted by a64pilot

ShaktisBoy,

Mind posting a link to that sound proofing?

Lol I'm so cheap I made it myself. I used a single layer of 12x12 rubber tiles sandwiched with industrial adhesive between common foil lined thermal barrier sheeting you can get at any hardware store. After going to several different boating stores and seeing the different types at 15.00 a sq foot or more the choice was easy. By the way the it does a great job. It's been completed since December and is holding up perfect so far. If I have to change it out anytime soon I will report back here. The hardest part of this project was without a doubt making the system leak free and figuring out the proper air conditioner accumulator and R234A charge. The Hvac industry is very secretive. In the end I ended up using the same charge as a large passenger van which was 34.2 ounces of R134A and typical hi and low side pressures. I had to bypass the pressure switches to get the charge in.



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[carpe vita]

I saw this installation and it looks amazing and it is doing a great job.
My hat is off to you Marti!
I know you just sailed off to the Bahamas, have a great trip!