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10-12-2014, 07:12
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#31
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Moderator Emeritus
Join Date: May 2008
Location: Fort Lauderdale, FL
Boat: 48 Wauquiez Pilot Saloon
Posts: 5,975
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Re: Generator install
Still make me smile every time you mention how happy you are with your boat, and how great a shape she's in...
__________________
In the harsh marine environment, something is always in need of repair...
Mai Tai's fix everything...
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10-12-2014, 07:17
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#32
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Moderator Emeritus
Join Date: Oct 2013
Location: Jacksonville/ out cruising
Boat: Island Packet 38
Posts: 31,351
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Re: Generator install
If anyone is interested, this is the old Gal, I bumped into this video after having bought her.
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10-12-2014, 07:48
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#33
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Registered User
Join Date: Mar 2003
Location: Wherever the boat is!
Boat: Marine Trader 34DC
Posts: 4,619
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Re: Generator install
Here's how our day goes using the generator. This early Florida mornings in the 30's we wake up early, fire up the generator and turn on the heat, a 16,000 BTU unit. It runs long enough to bring the cabin temps up to mid 60's and we shut off the heat. If we use less appliances, we can let it run. The coffee pot, toaster, microwave, TV, satellite receiver, computers, printers, and battery charger all can be run at the same time. Once we're finished with the coffee brewing and the toaster, the heat can come back on with everything else running. In the evening, we can run the air conditioning in warmer weather along with the TV, etc., battery charger, computers, lights, etc. We don't usually run heat or AC while underway, but we can easily. The hot water heater only needs to run for about 30 minutes to make enough hot water for shower and washing dishes. The AC/heat doesn't like to start up with the hot water heater on at first. Once the hot water heater throttles back, it doesn't matter. So we do have to manage the big loads, but the 3.5 handles everything else, even all at once without a strain. You need to do a thorough analysis of your power needs before considering what size generator you should install. The NextGen sips diesel. Chuck
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10-12-2014, 07:54
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#34
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Registered User
Join Date: Aug 2009
Posts: 162
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Re: Generator install
We have a 3.5 kw Nextgen installed in our H356. It was installed in the cockpit lazarette before we bought our boat by a NextGen dealer. It is installed above the water line. The exhaust is routed up to the gunnel inside the locker and down and out through the swim platform. The raw water does not have an anti syphon loop as far as I can remember. It has been in the boat 6 years now, has about 900 hrs on it. We don't use it very much. It was installed in a noise enclosure and the locker was lined with the aluminized rubber engine room foam. The noise level in the boat is not bad. I've asked boats anchored around us and most can not tell when it is running, usually they hear it more when down below. I think the sound is getting into our hull and traveling through the water.
We upgraded our battery charger to a Sterling 50 A. And our alternator to 140 A. when we changed to AGM batteries(400 Ahr). High output battery chargers and alternators are not as useful with flooded batteries.
Our project this year is 325W of solar on the arch above the bimini.
Bob
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10-12-2014, 08:04
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#35
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Registered User
Join Date: Oct 2005
Location: Presently on US East Coast
Boat: Manta 40 "Reach"
Posts: 10,108
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Re: Generator install
Quote:
Originally Posted by BobH260
We upgraded our battery charger to a Sterling 50 A. And our alternator to 140 A. when we changed to AGM batteries(400 Ahr). High output battery chargers and alternators are not as useful with flooded batteries.
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50A is still pretty anemic for charging. Our flooded batteries soak up 110A when they are below 75%, and keep sucking that for half an hour before falling to 85A or so. By the time they get down to only accepting 50A, I turn the charger off and let the solar take them to float. Usually I shut the charger off when the batteries are only taking 60-70A.
These flooded batteries accept the same amount of charge from our HO alternator.
A typical 0.25C charge rate for 440Ahr of flooded batteries is 110A…
Mark
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You do not need a parachute to skydive. You only need a parachute to skydive twice.
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10-12-2014, 08:04
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#36
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Moderator Emeritus
Join Date: Oct 2013
Location: Jacksonville/ out cruising
Boat: Island Packet 38
Posts: 31,351
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Re: Generator install
So,
Any problems to report on the little Nexgens?
I know power is not particularly stable, but the newer ones have a Syncro gen head, so maybe that has changed?
I've heard also the the exhaust doesn't last very long, but there is also a new exhaust that fixes that
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10-12-2014, 08:11
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#37
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Registered User
Join Date: Oct 2005
Location: Presently on US East Coast
Boat: Manta 40 "Reach"
Posts: 10,108
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Re: Generator install
Our typical generator use: Every 2 days, we turn on the generator for an hour to run the 120A charger and make water. In that hour, the batteries get well into absorption so that the solar can take over and give them a deep full charge to float. And we have 35 gallons of water in the tank, and all our computers, rechargeable batteries, etc are fully charged. Sometimes it is 1.5hrs for 50 gallons if we have been using a lot of water (laundry day, for example).
Our less-typical generator use is running for an hour every day when it is cloudy because the solar isn't enough. Often times it is raining then, so we have collected water - we then run the water heater for the load and have hot water.
Our non-typical generator use is for AC to cool the boat before bed when the bugs, heat and humidity are too much.
Mark
__________________
www.svreach.com
You do not need a parachute to skydive. You only need a parachute to skydive twice.
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10-12-2014, 08:17
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#38
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Registered User
Join Date: Oct 2005
Location: Presently on US East Coast
Boat: Manta 40 "Reach"
Posts: 10,108
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Re: Generator install
Quote:
Originally Posted by a64pilot
So,
Any problems to report on the little Nexgens?
I know power is not particularly stable, but the newer ones have a Syncro gen head, so maybe that has changed?
I've heard also the the exhaust doesn't last very long, but there is also a new exhaust that fixes that
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Our 5.5kW blows its excitation capacitor every 100-200hrs. These cost <$10, commonly available on every street corner in the world, and I have it externally mounted so changing it takes only a minute or so. I don't know why it does this, and others have not had this problem. It is not heat-related, and the generator is never loaded >80%. It does not seem to be related to either high-induction or high-resistance loads, nor to high-amp start currents. The wiring is good.
If this capacitor wasn't so inexpensive and easy to swap out, I would be much more bothered by this.
Stability of the power isn't the problem with these types of gensets - it is the quality of the power. They are very noisy, and this is inherent in these small, light, high speed gensets. I have posted on this in another thread here.
Mark
__________________
www.svreach.com
You do not need a parachute to skydive. You only need a parachute to skydive twice.
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10-12-2014, 08:58
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#39
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Moderator Emeritus
Join Date: Oct 2013
Location: Jacksonville/ out cruising
Boat: Island Packet 38
Posts: 31,351
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Re: Generator install
The new little 3.5's supposedly use a Syncro head as opposed to a Markon head, what that means operationally, I don't know, but am curious as to why they changed, Markon is still on the 5.5.
I've read your thread about the noise, that is what I meant by stable power, not fluctuating Hz rate or anything like that.
My intended use pretty much duplicates yours, if it goes as planned anyway.
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10-12-2014, 09:01
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#40
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Registered User
Join Date: Aug 2009
Posts: 162
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Re: Generator install
Quote:
Originally Posted by colemj
50A is still pretty anemic for charging. Our flooded batteries soak up 110A when they are below 75%, and keep sucking that for half an hour before falling to 85A or so. By the time they get down to only accepting 50A, I turn the charger off and let the solar take them to float. Usually I shut the charger off when the batteries are only taking 60-70A.
These flooded batteries accept the same amount of charge from our HO alternator.
A typical 0.25C charge rate for 440Ahr of flooded batteries is 110A…
Mark
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I'm surprised you go below the 50% SOC on your bank, it is usually not recommended for max battery life. I think most flooded cells have a recommended max charge rate of about 10 or 12% of the charge capacity, you must have a very large bank to be running 110 Amps into it. I try to never go below 50% SOC, our AGM bank, it will take 125A from our alternator (I have it dialed down a bit on our Balmar external alternator).
The battery charger does pretty much run flat out on the AGMs. The reason we bought the 50A battery charger was because we had the high output alternator and think if the generator ever dies we will go back to an EU2000, and this battery charger is about as big as we could use with one of those.
Our needs are about 125 Ahr per day so the solar running in Florida and Bahamas we hope will limit our need to run the generator, charger or diesel. We usually are either anchoring and moving or in a marina slip. Occasionally hanging out on a mooring bal would be the time to use the generator.
Bob
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10-12-2014, 09:27
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#41
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Registered User
Join Date: Feb 2009
Posts: 1,315
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Re: Generator install
Quote:
Originally Posted by a64pilot
Question is, do I need a vented loop? What determines the need of a vented loop?
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You may mean a Goose Neck and yes it is valuable in preventing ingress of water so long the Goose Neck is installed high enough.
Quote:
Originally Posted by chala
gooseneck,
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By the way best to have separate trough hull exhaust, for reason of weight I have a common one, this require to operate exhaust valves otherwise the running engine may blow back into the one not running.
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10-12-2014, 09:43
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#42
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Registered User
Join Date: Oct 2005
Location: Presently on US East Coast
Boat: Manta 40 "Reach"
Posts: 10,108
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Re: Generator install
Quote:
Originally Posted by BobH260
I'm surprised you go below the 50% SOC on your bank, it is usually not recommended for max battery life. I think most flooded cells have a recommended max charge rate of about 10 or 12% of the charge capacity, you must have a very large bank to be running 110 Amps into it. I try to never go below 50% SOC, our AGM bank, it will take 125A from our alternator (I have it dialed down a bit on our Balmar external alternator).
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I don't think our batteries have ever been below 50% SOC. As I posted, they will accept a good bit of current above 50% SOC.
Even so, going below 50% SOC does not decrease battery life significantly. It is not recharging them that does that. Think about forklifts and golf carts, for example.
Flooded cells, like all LA batteries, will take what they want - there is no real reason to artificially limit the current to them in bulk charge, and you can't "push" more into them with a higher current source. If mine are taking 100A from the 120A charger, and I turn on the HO alternator with another 100A possible, the batteries simply don't accept anymore than 100A. 0.25C is an acceptable rate for FLA's. Like I mentioned, a 440Ahr bank has a 0.25C rate of 110A.
Our bank is nominally 675Ahr (6 Trojan T105's).
Most good battery chargers have the ability to dial back their output to match the power source. Even though ours is 120A, I can set it to any maximum charge current I choose, should I want to use a portable generator with it. Our previous charger of a different brand had this ability also.
Mark
__________________
www.svreach.com
You do not need a parachute to skydive. You only need a parachute to skydive twice.
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10-12-2014, 11:05
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#43
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Moderator Emeritus
Join Date: Oct 2013
Location: Jacksonville/ out cruising
Boat: Island Packet 38
Posts: 31,351
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Re: Generator install
Mark,
Stupid question, if you replaced your cap with a larger one, would that help? Different thing, but I've done that with electric motors and it has helped.
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10-12-2014, 13:11
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#44
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Registered User
Join Date: Oct 2005
Location: Presently on US East Coast
Boat: Manta 40 "Reach"
Posts: 10,108
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Re: Generator install
Quote:
Originally Posted by a64pilot
Mark,
Stupid question, if you replaced your cap with a larger one, would that help? Different thing, but I've done that with electric motors and it has helped.
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While the voltage rating does not matter, the capacitance determines the excitation voltage, and thus the system voltage. A larger capacitance would increase the system voltage. I do use the largest voltage rating I can find, but most of them are pretty standard at 450V - which is far higher than system voltage.
Mark
__________________
www.svreach.com
You do not need a parachute to skydive. You only need a parachute to skydive twice.
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10-12-2014, 14:18
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#45
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Moderator Emeritus
Join Date: Oct 2013
Location: Jacksonville/ out cruising
Boat: Island Packet 38
Posts: 31,351
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Re: Generator install
I'm familiar with how Caps are made and why they work, just seems about the only thing that can happen to a cap is the insulation break down?
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