How do you choose a GENSET?

[lifeofreilly57]

OK, I have a Northern Lights 5kw generator onboard with a full array of gear, battery charging, refrigeration, water heating (I like warm showers), watermaking (for the warm showers anywhere), all the onboard electronics, as well as charging all our portable devices (part of our livelyhood depends on working remotely), with everything we have to load it with, which we do while running, I find I'm often using a low load on the generator.
It's not the quietest piece on the market, but quite robust, I am currently doing some intake mods and other mods to make it much more livable, most of which are fairly inexpensive. So far it's been stone dependable. Most of the modifications to reduce noise are fairly inexpensive.

[SM6WET]

I would do things a bit different.
Been thinking alot on this issue the last couple of years planning my future boat and since I am a ham going to enjoy my hobby alot on the boat I would need quite a large Ah available on my battery bank as well as the availability to extract a large quantity of wattage at any one time of those few needed, talking about near 4Kw just for the radio amplifier.


I Think the way to go is LiPo batteries and by using a DC generator instead of a AC generator I could save a lot on fuel as a DC gennie adjust itself and additionally you dont have to make AC to invert into DC to charge the batteries which loose a lot of energy but instead just charge the batteries and use a inverter for the few things that need to run on 240/120VAC.
Also, depending the size of the boat consider going 24v system.

[mako]

Originally Posted by SM6WET

I Think the way to go is LiPo batteries and by using a DC generator instead of a AC generator ... just charge the batteries and use a inverter for the few things that need to run on 240/120VAC ... depending the size of the boat consider going 24v system.

Interesting concept. Some thoughts:

• How many a/c appliances do you run: aircon, stove, oven, washer, watermaker, heat, etc.?
• With alot of a/c appliances then youmay have multiple very large inverters to run them, which is lower in efficiency;
• If you need HUGE battery storage then instead of going with the incredibly expensive LiPo batteries, perhaps check out 2volt 1000 amp-hr, storage batteries. Industrial rated wet cells but can be run down below 50% to no end of 2000 cycles. Very heavy of course.

[mako]

Originally Posted by hoppy

I've been told that you need 6 to 7 time the nominal current to start the compressor

You need to check with the manufacturer of each electric appliance and inquire as to the "locked rotor" rating. That is what will tell you the startup draw. It's very strange how there is such a vast range from 2X to 3X or more. I suppose it depends on the specs of the motor and how heavy the load is.

[Divedoug68]

Thank you all for the replies, advice, questions and thoughts. I'm working with the broker's Service/Commissioning VP who happens to be an Electrical Engineer. We are working thru the various aspects of the features I want to install to determine the best GENSET, type and number of inverters, solar and battery array.

Anyway, this is a great FORUM and I will definitely be using it in the future!

Cheers

[Ip485]

As someone else said if you are running a lot of high consumption items at the SAME time then you will need this level of output.

I have 8Kw and a coltri compressor. I can run the compressor and the A/C but any more load and it will trip.

In reality I hate the Genset because it does rumble away (a bit, not a lot to be fair) so I try and use it as little as possible but with chartering this may not be possible. On a charter boat if you are using it a lot you will need to think about removing the heat from the engine room and definitely will want a silenced underwater exhaust. Also unless you watch the loading there might be a temptation to leave it running for long periods with very little load.

Personally I have gone the route of a big solar array - just short of 1,000W which pretty much through an inverter does everything I want EXCEPT the compressor, washing machine and water maker for which there isnt a substitute.

You will find installing a soft start is also very useful in preventing some of these items tripping the inverter or Genset on start up.

[Bulawayo]

We removed our generator and air conditioning when we bought our last boat. We are reliant on scoops and low draw fans instead for our comfort. There are times when it gets very uncomfortable and have even been known to stern anchor.
For our use I cannot think of any reason, beside air conditioning, that warrants having a gen set on board. I do read of more people adopting DC generators but have no experience of them. Our dive compressor runs of a petrol powered engine.
I am not happy to have many systems dependent upon a single source either. All our systems are stand alone. We dont like to hear an engine running all night to power air conditioning either. The only mains power sources we have are the invertors (we have a 2000w and an 180w) of which the 180watt is in constant use use recharging toothbrushes, laptops, iPods etc and our trusty Honda i20 which is rarely used. For us, that is plenty.

Originally Posted by Dockhead

Well, you don't need an 11kW generator to run a dive compressor (!).

If I were setting up a nice long range cruising catamaran from scratch, I would manage electricity this way:

1. Very large heavy duty alternators on both main engines, driven by serpentine belts, at least 3kW each, with Balmar regulation (the kind that lets you derate them).

2. Large solar installation.

3. A decent sized LiFePo battery bank.


The huge acceptance rate of LiFePo batteries allows you to charge efficiently with short generator runs, making it practical to use main engines for this (which don't like long runs with light loads).

In my opinion, two diesel engines on a catamaran is quite enough.

This kind of system wouldn't be too good for running air conditioning continuously at anchor. But query whether it's worth dragging around all that weight, just to have that capability. Most cruisers in the tropics are pretty happy using wind scoops at anchor, and A/C at the dock.

[Dockhead]

Originally Posted by Bulawayo

We removed our generator and air conditioning when we bought our last boat. We are reliant on scoops and low draw fans instead for our comfort. There are times when it gets very uncomfortable and have even been known to stern anchor.
For our use I cannot think of any reason, beside air conditioning, that warrants having a gen set on board. I do read of more people adopting DC generators but have no experience of them. Our dive compressor runs of a petrol powered engine.
I am not happy to have many systems dependent upon a single source either. All our systems are stand alone. We dont like to hear an engine running all night to power air conditioning either. The only mains power sources we have are the invertors (we have a 2000w and an 180w) of which the 180watt is in constant use use recharging toothbrushes, laptops, iPods etc and our trusty Honda i20 which is rarely used. For us, that is plenty.

Well, it’s a bit of thread drift, but I would write a word or two in favor of generators on boats without air conditioning. A few points:
1. If you ever go to LiFePo batteries, you definitely want either a generator or a high capacity alternator or both, in order to take advantage of the high acceptance rate of those batteries. LiFePo batteries really work well with this kind of charging (just like Lead-Acid works really well with solar, which is capable of giving the long slow charge which Lead-Acid loves but which kills generators).

2. A generator is a good partner to other charging sources, and doesn’t need to be a “single point of failure”. On my boat, it’s a 2.5kW high output schoolbus alternator. I can get by with either of these alone, but both together is wonderful – always abundant power in any situation.

3. Solar power is great, but not every boat can fit enough of it to support their needs. My boat is set up for good sailing upwind, and there’s just no way I would ruin it all with the windage of a large solar installation.

4. Wind power, while an efficient producer of noise and windage, is not an efficient producer of power, or any producer at all (in my experience).

So generators in my opinion are very useful indeed on cruising boats which are not totally Spartan in terms of electrical gear. I don’t have air conditioning, but I have washer/dryer and plenty of other electrical gear. And I don’t like to be a power miser on board like my father was.

[Bulawayo]

I agree with much of this, see below;

[QUOTE=Dockhead;2188450]Well, it’s a bit of thread drift, but I would write a word or two in favor of generators on boats without air conditioning. A few points:
1. If you ever go to LiFePo batteries, you definitely want either a generator or a high capacity alternator or both, in order to take advantage of the high acceptance rate of those batteries. LiFePo batteries really work well with this kind of charging (just like Lead-Acid works really well with solar, which is capable of giving the long slow charge which Lead-Acid loves but which kills generators).
Im looking at a change of batteries next year. I am also looking at a DC generator as its smaller / lighter. However, our >1000watts of solar does a very good job at present.

2. A generator is a good partner to other charging sources, and doesn’t need to be a “single point of failure”. On my boat, it’s a 2.5kW high output schoolbus alternator. I can get by with either of these alone, but both together is wonderful – always abundant power in any situation.
We used to have an engine driven water maker which didn’t work well for us. I really don’t like piling the hours onto our main motors, especially when alternatives exist.

3. Solar power is great, but not every boat can fit enough of it to support their needs. My boat is set up for good sailing upwind, and there’s just no way I would ruin it all with the windage of a large solar installation.
Yup, but we have the space for these. I cant say we have noticed any big influence. Our panels sit flat and are not adjustable.

4. Wind power, while an efficient producer of noise and windage, is not an efficient producer of power, or any producer at all (in my experience).
We agree…..we used to have WindBuggers – and never saw anything appreciable from them. We have also had Rutlands, again, without anything significant. One Windbugger also decided to eat a bird and the damaged blade put it out of balance immediately. We now have two D400’s and these really do make a contribution, especially over 12 knots. We keep them tied off whilst sailing and only ever use them at anchor. However, these do make a meaningful contribution. I can definitely recommend these. They are also quiet and without noticeable vibration.

So generators in my opinion are very useful indeed on cruising boats which are not totally Spartan in terms of electrical gear. I don’t have air conditioning, but I have washer/dryer and plenty of other electrical gear. And I don’t like to be a power miser on board like my father was.
We also have a mains automatic washing machine and it gets used regularly.

It sounds that the difference is in the solar panels and wind gennies.
A friend has changed to lithium power and has nearly 1000watts of solar (no air con but does have a washing machine, 12v water maker, and a fridge and separate freezer as his comforts) with a family of four and he also says he very rarely has to resort to his main engines; it takes several days of heavy overcast before that happens. We are certainly not especially careful with power.

Its horses for courses but at the end of the day it still comes down to the fact that the main reason for having a separate diesel generator is to run air conditioning.
No ac and there appears no justification for the gen set.

[kryg]

I fully agree with the dislike of engine noise, it is a big issue, so much so I hated the engine driven Compressor also. I suspect my spiritual angel of my ear drums must have given me a hand as one day the hooker engine seized.

My solar panels total 420 watts I have 500 amp AGM house batteries one inverter for the coffee grinder and my two laptops computers have there own Targus 70w power note adapters used for car or aeroplanes. (Note if you purchase a Targus adapter for your laptop get spare backups they are fragile units).

Also, I have a 2000 watt Ryobi generator that is used only a few times a year run on the deck when needed the problem here is if it rains you can't use it. Needs to be protected.

Since I had a number of private questions on my hooker setup.
And for thoughts that are interested, in my diving compressors experiences and weight, noise and bulk savings on board. Read on.



I qualified as sports diver on dive tanks I used for many years...who is fed up with messing with dive tanks.



I'm not what one would call a pro-diver, I never dive anymore below 18 meters for my health and safety reasons, (Called fear of unforeseen mechanical failer) LOL,



Scuba tanks on a boat are not practical other than day trips on a small sailing boat so I switched by purchasing a gas -petrol run hookah compressor, lovely while it worked but this failed while I was with the swimming with the fishes.



Also like the Ryobi generator the compressor needed to be stored below decks when not in use, (I had room for only one).



The 5 hp hookah setup was big and heavy and its bulk unit it took up too much space on my boat plus I hated the noisy petrol engine.

I replace it by purchasing a little-used 12-volt complete 2 diver Hookah setup on Gumtree (kind of different eBay site) for $650 it is not a DYI product but from a manufacturer. Unlike my last petrol run compressor, it is very light and small and it runs off my boats batteries that are never depleted as they are solar charging while I dive.



Detail of my Hookah setup:


My system is (for 2 divers) 12-volt air compressor that is mounted in what is best described as a normal sized fishing tackle box with a 12 volts high capacity air pump. Open the lid and plug in the 12-volt lead and the dive hoses from the accumulator air tank.


From the compressor inside the compressor box there is a positive lock air outlet with a quick fit hose connector. Here the 10' hose is connected into a separate reserve floating accumulator air tank build out of stainless steel.

This air accumulator tank floats on the water and on the other end another 10' hose is fixed to the tanks air outlet with a quick positive lock hose connector, this end is connected to a 10mm x 100' dive hose that has a Y-fitting for two divers and the two other hoses are 25' long connected to the Y Fitting go to two diving belts one for each diver. All end hose fittings are positive lock quick release connectors. at the dive belt the air regulator then is plugged into the air hose outlet.



Note: if I am cleaning the hull alone (Whats New?) I dive connected directly to the main 100' air hose,



There are a number of different hookah setups products available, some like mine others presented in different accumulator air tanks mounted with the compressor some not. The main consideration is the capacity of the air compressor. I discovered there are two different size 12-volt air compressors, one for single divers and the larger unit for two divers. Even if I was to dive mostly solo (Not recommend) I still would buy the larger capacity air compressor.



Reference: I don't have this hookah brand nor any connection to this firm. This link is only a reference their offering seems very expensive. I give it as a link only because it is like to my hookah setup but with a stainless steel accumulator tank, this link will give you an idea how my system is setup. 12V Double Deck Snorkel System - Aquasea Underwater Products - Wetsuit & Drysuit Repairs and Alterations


Happy hull cleaning and sailing.

Originally Posted by Bulawayo

We removed our generator and air conditioning when we bought our last boat. We are reliant on scoops and low draw fans instead for our comfort. There are times when it gets very uncomfortable and have even been known to stern anchor.
For our use I cannot think of any reason, beside air conditioning, that warrants having a gen set on board. I do read of more people adopting DC generators but have no experience of them. Our dive compressor runs of a petrol powered engine.
I am not happy to have many systems dependent upon a single source either. All our systems are stand alone. We dont like to hear an engine running all night to power air conditioning either. The only mains power sources we have are the invertors (we have a 2000w and an 180w) of which the 180watt is in constant use use recharging toothbrushes, laptops, iPods etc and our trusty Honda i20 which is rarely used. For us, that is plenty.

[savoir]

I'm wondering which would be more fun, the hooker setup or the hookah setup.

[Lucky Larry]

Originally Posted by Divedoug68

I have been doing a lot of research on generators since I am about to purchase my first Catamaran. I've looked across the board and would like some advice on which one is the most reliable as well as easier to service/find spares. I've been looking specifically at the Onan 11KW 60Hz versus the Northern Lights 9KW 60Hz.

Any thoughts would be greatly appreciated.

'How do you choose a GENSET?' I placed a check in the box on the option sheet when ordering our boat.

[Bulawayo]

Good to read, thanks. Im a bit like Jimmy Cornell in his earlier days - I collect information from other cruisers on what works and what doesnt and have been collating this for years.

Originally Posted by kryg

I fully agree with the dislike of engine noise, it is a big issue, so much so I hated the engine driven Compressor also. I suspect my spiritual angel of my ear drums must have given me a hand as one day the hooker engine seized.

My solar panels total 420 watts I have 500 amp AGM house batteries one inverter for the coffee grinder and my two laptops computers have there own Targus 70w power note adapters used for car or aeroplanes. (Note if you purchase a Targus adapter for your laptop get spare backups they are fragile units).

Also, I have a 2000 watt Ryobi generator that is used only a few times a year run on the deck when needed the problem here is if it rains you can't use it. Needs to be protected.

Since I had a number of private questions on my hooker setup.
And for thoughts that are interested, in my diving compressors experiences and weight, noise and bulk savings on board. Read on.



I qualified as sports diver on dive tanks I used for many years...who is fed up with messing with dive tanks.



I'm not what one would call a pro-diver, I never dive anymore below 18 meters for my health and safety reasons, (Called fear of unforeseen mechanical failer) LOL,



Scuba tanks on a boat are not practical other than day trips on a small sailing boat so I switched by purchasing a gas -petrol run hookah compressor, lovely while it worked but this failed while I was with the swimming with the fishes.



Also like the Ryobi generator the compressor needed to be stored below decks when not in use, (I had room for only one).



The 5 hp hookah setup was big and heavy and its bulk unit it took up too much space on my boat plus I hated the noisy petrol engine.

I replace it by purchasing a little-used 12-volt complete 2 diver Hookah setup on Gumtree (kind of different eBay site) for $650 it is not a DYI product but from a manufacturer. Unlike my last petrol run compressor, it is very light and small and it runs off my boats batteries that are never depleted as they are solar charging while I dive.



Detail of my Hookah setup:


My system is (for 2 divers) 12-volt air compressor that is mounted in what is best described as a normal sized fishing tackle box with a 12 volts high capacity air pump. Open the lid and plug in the 12-volt lead and the dive hoses from the accumulator air tank.


From the compressor inside the compressor box there is a positive lock air outlet with a quick fit hose connector. Here the 10' hose is connected into a separate reserve floating accumulator air tank build out of stainless steel.

This air accumulator tank floats on the water and on the other end another 10' hose is fixed to the tanks air outlet with a quick positive lock hose connector, this end is connected to a 10mm x 100' dive hose that has a Y-fitting for two divers and the two other hoses are 25' long connected to the Y Fitting go to two diving belts one for each diver. All end hose fittings are positive lock quick release connectors. at the dive belt the air regulator then is plugged into the air hose outlet.



Note: if I am cleaning the hull alone (Whats New?) I dive connected directly to the main 100' air hose,



There are a number of different hookah setups products available, some like mine others presented in different accumulator air tanks mounted with the compressor some not. The main consideration is the capacity of the air compressor. I discovered there are two different size 12-volt air compressors, one for single divers and the larger unit for two divers. Even if I was to dive mostly solo (Not recommend) I still would buy the larger capacity air compressor.



Reference: I don't have this hookah brand nor any connection to this firm. This link is only a reference their offering seems very expensive. I give it as a link only because it is like to my hookah setup but with a stainless steel accumulator tank, this link will give you an idea how my system is setup. 12V Double Deck Snorkel System - Aquasea Underwater Products - Wetsuit & Drysuit Repairs and Alterations


Happy hull cleaning and sailing.

[kryg]

If you are wondering you have not lived yet.

Originally Posted by savoir

I'm wondering which would be more fun, the hooker setup or the hookah setup.

[Zzmeyer]

I have a 7.5 kW Onan on a fifty foot sailboat. Seems to me that permits 60 amps in theory which is greater capacity than my 50 amp shore power. Generators like a load so over spec doesn't seem like a good idea. One data point on the Onan is that my dealer said they have a reputation of eating impellers. Mine self distructed at fifty hours and requires a fair amount of disassembly to replace. Other threads imply the problem is an installation issue.


Sent from my iPad using Cruisers Sailing Forum