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Old 06-01-2014, 17:16   #31
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Re: Quietest Diesel Gen set?

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Safari worked fine for me....

I'm on an Ipad, not a computer, maybe that's it?
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Old 06-01-2014, 17:21   #32
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Re: Quietest Diesel Gen set?

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I don't have a boat yet, but have now added a Gen to the list of the wife's "must haves", so this boat I'm going to buy now among other things has to have room for a Gen set. DC gens seem to make a lot of sense, except where do you get a 5KW or so inverter and assuming there is one that large, what does it cost? I assume you would connect it to the house bank and use the house bank for a sort of accumulator?

Frankly since you haven't purchased a boat yet and the wife considers generator and AC a must have. Buy a boat that already has one. It will cost less and you will be sailing and cruising sooner rather than refitting.

Jay

PS Adding a generator to a boat that doesn't have one already, can and likely will run 20 to 25 thousand dollars turn key. It's not just the generator it's transfer switches and related wiring, exhaust, thru hulls sound shielding etc.
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Old 06-01-2014, 17:21   #33
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Re: Quietest Diesel Gen set?

60 amps at 120 V is 7200W, you sure an Ac will pull that much at start up? That woul mean a 7.5 KW gen is minimal at best. If your correct it needs a starting capacitor. Now I don't know why, but on my RV I can run either AC to include starting and a couple of TV's, battery charger etc all off of one 15 amp normal wall outlet with 100' 12Ga extension cord. I think my AC's are 13,500 BTU, wonder why the marine ones pull so much?
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Old 06-01-2014, 17:28   #34
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Re: Quietest Diesel Gen set?

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Frankly since you haven't purchased a boat yet and the wife considers generator and AC a must have. Buy a boat that already has one. It will cost less and you will be sailing and cruising sooner rather than refitting.

Jay

Your right, an already installed gen is on the list. However if I only look at boats with Gen's, I'm really reducing the boats to look at. Actually we have come up with several like to have's and a few must haves. A gen as long as the boat has a good place to install one is in my like to have list. The must have is an accessible place to put a gen.
I know people like to bash Hunter's, but a 356's left lazarette seems an excellent place
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Old 06-01-2014, 18:29   #35
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Re: Quietest Diesel Gen set?

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Thanks Rick, unfortunately Safari won't download the test, have to wait until I'm on a real computer I'm afraid
I use Safari too. It does download, but it takes awhile. Watch the little box on the top right of the screen, and you will see it downloading. If nothing works, PM me and I will email you a copy.
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Old 06-01-2014, 19:09   #36
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Re: Quietest Diesel Gen set?

16,000 BTU is a big air conditioner. Look up the startup specs for your planned air conditioner (sometimes listed as "locked rotor load"). The 60 amps is just for a split second as the compressor starts but it's there. A small genset can often "get by" the spike but this is a common problem area. Some A/C manufacturers off a "soft start" option that reduces this momentary load.

One of the features of the Victron charger/inverter (mentioned in that report download) is that their inverters can be wired between a genset and the load. If the load briefly exceeds the genset capacity the inverter draws the extra amps from the boat batteries. It also automatically tapers any battery charging to not overload the genset. This lets you put in a smaller genset than the peak load would normally require.
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Old 06-01-2014, 20:42   #37
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Re: Quietest Diesel Gen set?

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60 amps at 120 V is 7200W, you sure an Ac will pull that much at start up? That woul mean a 7.5 KW gen is minimal at best. If your correct it needs a starting capacitor. Now I don't know why, but on my RV I can run either AC to include starting and a couple of TV's, battery charger etc all off of one 15 amp normal wall outlet with 100' 12Ga extension cord. I think my AC's are 13,500 BTU, wonder why the marine ones pull so much?
I run (2) 16kbtu ACs with a 7.6kw generator. I measured the inrush on each AC, ~57a @120v. The generator starts/runs both of them.

BTW, I have a Mase IS7.6, mounted in an enclosure. It has it's own intercooler, no need for a blower/ventilation for it's space. It's a Yanmar 3TNE74, engine parts sourced from Yanmar. The backend is a Mecc-Alte capacitor regulated.

It's been a good unit.
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Old 06-01-2014, 21:04   #38
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Re: Quietest Diesel Gen set?

A 15amp outlet hooked to a public utility can provide much more than 15 amps for a half a second.

Dot Dun's 7kw genset would be fine. Only one of his two A/Cs start at a time. The other is drawing about 10 amps running. But a 4-5kw genset might have trouble getting a big A/C started without something like capacitors or the Victron feature.
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Old 06-01-2014, 22:06   #39
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Re: Quietest Diesel Gen set?

I have a 5kw Kohler (3 cyl. Yanmar engine). Very quiet. We can watch a movie while charging the batteries and pulling the humidity out of the sleeping areas with no noise issue. It is mounted in the engine room under main salon. No sound shield. If it had a water separator our neighbor at any anchorage would not know it was running. It will run two 12,000btu air conditioner units, charge batteries and run all the usual little stuff. Or one AC unit and the electric dryer, charger and little stuff. Or one AC and the microwave ect. The AC units are older and have high inrush at start. If they both get started at the same time sometimes the gen set won't pull the load. If I replace the inverter I will use one that will "boost" power as required. Most of the time 5kw is plenty for us. My only irritation is the proprietary normal mx stuff like oil filters and water pump belts. I have a hard time believing that they make enough money from those things to make it worth the customer needing to take an expensive cab ride to an authorized dealer when a NAPA store is one block away. (I know I should plan ahead but I was just back to the states and didn't want to spend more time than necessary at a marina.)
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Old 06-01-2014, 22:55   #40
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Re: Quietest Diesel Gen set?

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I have a 5kw Kohler (3 cyl. Yanmar engine). Very quiet. We can watch a movie while charging the batteries and pulling the humidity out of the sleeping areas with no noise issue. It is mounted in the engine room under main salon. No sound shield. If it had a water separator our neighbor at any anchorage would not know it was running. It will run two 12,000btu air conditioner units, charge batteries and run all the usual little stuff. Or one AC unit and the electric dryer, charger and little stuff. Or one AC and the microwave ect. The AC units are older and have high inrush at start. If they both get started at the same time sometimes the gen set won't pull the load. If I replace the inverter I will use one that will "boost" power as required. Most of the time 5kw is plenty for us. My only irritation is the proprietary normal mx stuff like oil filters and water pump belts. I have a hard time believing that they make enough money from those things to make it worth the customer needing to take an expensive cab ride to an authorized dealer when a NAPA store is one block away. (I know I should plan ahead but I was just back to the states and didn't want to spend more time than necessary at a marina.)
Does that unit run @1800rpm?
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Old 06-01-2014, 22:59   #41
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Re: Quietest Diesel Gen set?

I have a 5kw Northern Lights in a custom sound enclosure on our 356. Runs 16,000 btuh MarineAire, Hot water heater, microwave, TV with KVH sat antenna, chargers for iPhones, iPads, 2 computers, printer, and charges the batteries that run refrigeration, lighting, etc. It is 65 decibels in the cockpit and our aft bedroom. It is located in the port lazerette adjacent to our bedroom. In the salon, it is a hum, barely noticeable.

It has 3 cylinders running at 1800 RPM. It burns between .25 and .4 gallons per hour of diesel, depending on our load. It has underwater exhaust and cannot be heard 10 feet from the boat, so nobody at adjacent anchorage is affected. I have 2462 hours on it with minimal maintenance, ie oil changes and impellers and one belt. Burns less than a quart of oil in 250 hours.

I have had bad experience with Fisher Panda on 3 charter boats and a friends Cabo Rico 38. Some really like them, but I would not want one based on my past limited experience with them. All of them failed to work for the entire trips of 1 week except the Cabo Rico. It was too loud to run at night, so no heat and we got cold.

Northern Lights would be my first choice by a long shot. We run continuously while away from the dock and it makes my wife happy to have HVAC and all other amenities while not in a marina.
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Old 06-01-2014, 23:06   #42
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Re: Quietest Diesel Gen set?

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Does that unit run @1800rpm?
Yes. I should have mentioned that..
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Old 06-01-2014, 23:22   #43
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Re: Quietest Diesel Gen set?

The.

REAL ANSWER is, the one that runs the least amount of time to fulfill your load requirements.

It's really that simple.

First you must apply the Law of Conservation; to attain that realm.

That law is steeped in use as well as performance.

Performance is a design criteria.

Now to achieve the design, is the real issue.

Lets say you have to run your AC generator, every-time you run your AirCon. The start up load of the Air-Con is 2-4 times the running load.

Why not have a Hy-bred system that is DC based/with an engine driven AirCon.

Then marry that with a bat bank and an inverter with an DC Gen, that is auto-start. It will require 2 compressors.

By program the bats run the AirCon until they can't, then the gen starts and takes over the AirCon and charges the bats.

Lloyd

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In the smallish size range say 4 to 6 KW, 115V 60Hz, which one is quietest? I heard here and believe it's correct that noise is 80% structural and 20% accoustic. Makes sense to me, so I guess what I'm asking is which Gen is perceived to be quietest, good isolation from the hull would be important as well as exhaust noise?
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Old 07-01-2014, 02:31   #44
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Re: Quietest Diesel Gen set?

More than worry about the make, I would look carefully at the size. You don't need to size for normal start up peaks if you fit soft starts to all motors - so you reduce that load by 66%. Use inverters and decent battery capacity for much or all AC power and you can size for average rather than peak loads. Battery chargers / combined inverters sized to 80% genset capacity will limit overload. Net result is a much smaller, cheaper, more reliable and much more fuel efficient genset.
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Old 07-01-2014, 06:47   #45
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Re: Quietest Diesel Gen set?

We have a 5kw NextGen that runs two 16kbtu AC units no problem. It would probably have a problem if they both tried to start at exactly the same time, but that is a rare occurrence (hasn't happened yet).

Mark
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