10 kW Sailboat Generator

Depends on your own preference.

Both can be working, only make sure that with the diesel generator, you don't send a back flow to the main engine. Since the exhaust is water- cooled, the back flow could eventually let water enter the cylinders of which the exhaust valves are open.

Flow of the pumps and position of both engines should be controlled in a test run.

I see a potential problem with option #2.

The generator is unlikely to be designed to dump exhaust into flowing water, and possible backpressure could cause trouble.

I don't know if this is the case, but it's something to consider. You may have to run a separate exhaust pipe above deck.

The mase generator is a special sailboat generator with wet exhaust. They normally have their own waterlock - only I don't have one and I also don't have the space to install one. Thank you for your reply.

I assume that the main engine exhaust has a dry hot exhaust riser that then dumps seawater into a muffler to cool the exhaust for the trip aft to the waterlock. The differential of the height of the exhaust riser and the waterlock is to ensure against backflow to the engine, which would likely be fatal to hot exhaust valves, saying nothing of the consequences to the main engine innards. A following sea could overwhelm the waterlock, so the hot riser is additional insurance against that. So, the main engine being very expensive, I would be VERY chary about blithly just tapping into the main engine exhaust system. I did have such a tap-in for the genset on my Cal 246, but this was carefully engineered and tested by the builder. A side exhaust pipeing and waterlock is not without negative aspects, particularly exhaust fumes blowing into the cockpit.

I would go to the designer/builder and PAY them to design the use of the existing system, something they likely have already done AND TESTED.

Being 20 miles offshore rounding Hatteras in a gale with 20 foot seas is not the time to "try out" a system for bugs, but those ARE the conditions that a good system should handle easily, and be Foolproof.

Don't be the fool.

Some good observations so far, but installing the 2.5, running a separate, dry, insulated exhaust, exiting thru its own thru-hull-fitting, slightly below the water-line for noise reduction, could be a good solution. The temperature of the pipe would not become too high as the flow of the exhaust itself keeps things moderate. (would an inboard fitting for a zink anode for electrolysis prevention, of course) The cooling water outlet could be above water line.

On welding aboard sailboat. Used arc welding cables and attached to big battery bank. This works well, but sure does eat amps. used only occasionally.

Thank you for the reply. I need the generator for the dryer and the electric oven. I also want to switch to all electric appliances and the water heater. This is all on propane now and I have safety concerns about it. Also sometimes I will need to charge the battery banks when low. The engine alternator is 80 Amps. Welding, if needed I can easily do on my house bank, It is 12 Volts 1400Ah. Can even use the biggest rods.

Ahoy Cherryvan,

1400 AH is a large house bank. For years my house bank was 745 AH and it was fine for our full-time use, about 250 AH per day. When I replaced it recently (we got about 4 years from each set of four Trojan L-16 6v units) I went for six L-16 (the physical size) single cell (2.2V) units for 1150 AH.

Your 1400 AH battery is quite large. You will have no trouble running whatever you want from it. The main problem is keeping it filled up. We use 1300 watts of PV for that task but we have lots of roof space.

Lacking that, there are other paths you could take.

You could install two 12VDC alternators on your main engine. One that you already have for charging the engine starting battery, and a much larger - say 150 to 200 amp, with external regulator - for the house battery. Bear in mind that to avoid overheating do not load the alternators to more than 70% of their max output.

The main problem with that is your main engine will be underloaded (and the alternator driving gear may be overloaded). Conventional Wisdom says that a diesel engine should be loaded to 75 to 80% of its rated HP to avoid "wet stacking" and washing off lube oil on the cylinders with unburnt fuel. My genset is sometimes run for hours with only light to moderate loads without apparent ill effects so I have no experience with that.

You have a 2500W genset. 2500W divided by 14.5V is about 170A, plenty enough to charge your house bank using a robust battery charger. Why do you think you need a 10 KW generator? Can your current 2.5 KW genset operate your electric clothes dryer. You really don't have to run all your loads at the same time.

Perhaps, like one I had years ago, your dryer requires 120vac for the motor and timer, and 240vac for the heater. The dryer heater consisted of a resistance coiled wire heat element strung out in a circle around the back of the drum housing where the blower air passed over it and into the drum. I installed a ceramic insulated terminal post halfway around the circle forming a electrical connection halfway around the element. I applied 120vac across this point and the two original connection points. It got just as hot as the original arrangement, using the same power at twice the current.

The clothes dryer I have aboard now gets its heat from propane. The electric part runs perfectly on the 120vac inverter. Our tank-less (Paloma) hot water heater and galley stove run on propane.

Microwave, toaster oven, Cusinart, etc, etc run from the inverter.

Refrigeration is a big issue with most folks on boats. Our reefer and freezer are both 5 Cu/Ft Sundanzer units and we love them. They take only 2A each! Tie them down, hook them up, clean them out once a year. That's it!

Our galley propane tanks live under the aft companion ladder where they are well protected from the weather and are in constant sight and notice. We also have propane on deck for the barbeque, propane in the laundry room for the dryer, oxy/propane in Jan's jewelry shop for her torch, and oxy/aceteline in my shop. All but the galley tanks are shut off when not in use. The galley tanks are shut off if we leave the boat for an extended period. I have lived confidently with propane aboard for over 30 years.

While propane explosions are spectacular, in my experience electrical fires seem to be more common on boats.

I feel the dangers of propane are overstated. Actually, it is the little 1 lb bottles that I don't trust. After using one I unscrew the torch head and stick the bottle valve in my ear. It is often leaking. I poke the valve stem with something until it stops leaking. Even then, I store them in a drain-vented deck locker.

For further discussion of boat related issues I suggest you sign on to the Livaboard List at: join@liveaboardonline.com

This is a free discussion group of folks that have much experience in boat related subjects.

Bandership

Bandership.

Ours is a sail boat. The engine runs only when necessary. Here we even do canals on sail. Using dry exhaust locks is dangerous and not allowed any more by Lloyds.

We have wind turbines and 2 -125Watts solar panels

A wet lock system deals with everything and when installed well, doesn't need a lot of attention.

Those 1 lb bottles need attention. you are right, they often leak.

My main problem with propane is that there is no universal bottle connection. I have collected about 20 different tanks and ditto expanders during our travels.

Refilling bottles, even continent wide is a big problem. Bringing the supply for a 6 month cruise in a small sail boat - impossible. The boat crossed the AO 5 times and has sailed more than 400.000 NM's by now with the same hull.

Sorry that I reply in episodes. The 10 KVA generator I do not need to get. I have it.

It can also work with smaller loads.

I appreciate your help