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Old 08-08-2016, 17:18   #16
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Re: Are the BTU's on this Cruisair correct? If so, what genset would support it?

Your right an electrical horse power is exactly 746 watts not a 1000
don't get confused about Kilowatts and KVA
KVA is resistive load only
Air Cons are inductive
18000btu / 240volt /7.05 amps on heating and 5.75 cooling
have a nice day


Yes, include a loss factor. 15-20% is a good ball park number. In my practical experience, a horsepower is not 754 watts, but something closer to 1000 watts when all is said and done.

"How do I intend to operate away from dock? As above, only for sleeping A/C (and I really only need the 16,000 BTU unit on, I don't need the 12,000 BTU unit on). If I could have both - GREAT! If not, I'll live with it.

As mentioned, water pump would probably be the only other thing along with a few fans and a few LED lights. Battery charger and GPS/VHF/Autopilot would all be off during generator use."

I think I can honestly state that in the future you will not reduce the electrical demand load, but instead add to it. You don't list an anchor light. Nor any refrigeration loads. What about a stereo or tv? Do you plan to reharge your phone or laptop at anchor? All of these items call for the larger generator. We have a coffee maker, vacuum, etc. that all get used regularly, and require electricity. I have a corded drill, orbital sander, buffer, etc. Do an electrical load plan.

I have seen a lot of the portable Hondas while cruising, typically sitting on someone's foredeck laboring away to recharge batteries. In this use they see a couple hours a day of runtime. They are noisy, contrary to other reports, use gasoline which is dangerous as well as expensive, and being air-cooled (and built to a price point) have a much shorter anticipated life span - compared to a slow turning diesel genset. [The Panda is, I believe, a high speed diesel engine, not one of the 1800 rpm, long lasting units].

As a matter of fact, I think most cruisers use these small units in conjunction with solar or wind.

A built-in diesel genset would likely add value to your boat. The portables, no.

Why have to manage two fuel types? Gasoline is often more difficult to obtain than diesel. You cannot safely store it belowdecks. It goes bad faster than diesel, especially if ethanol is added.

A diesel genset can be programmed to operate automatically. Could that be useful to you?

Take a second look at a built-in system. Maybe second hand? And the boat shows are coming up soon.

Just my 2 cents.[/QUOTE]

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Old 09-08-2016, 07:20   #17
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Re: Are the BTU's on this Cruisair correct? If so, what genset would support it?

It seems that you have the equipment that you need for the job. but do you know how to combine teach into the component that is required when it ias needed is another story.
Are you working with some one who has had experience in Marine Aircons?

The general principal; you need to understand is that each component will deliver the amount of power necessary when needed for proper operation as long as the timing and other components are functioning properly as well.

So check and test run each component separately first. Both Gen sets must be turned on and run for a while (ten minutes) then combined. And operated a gain. for a half hour
Remember to start each unit separetly. Give time from one to the other,.
You should work.
Check all venting locations and air intake areas. as well as fuel consumption and filtering.
If you can run it for a couple of hours, shut it down and do the same all over again. you're good to go.

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Old 09-08-2016, 07:39   #18
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Re: Are the BTU's on this Cruisair correct? If so, what genset would support it?

Originally Posted by techmans View Post
The mentioning of running 2 generators in parallel sends the hairs in my neck up.

I hope you don't mean feeding the output of both into the same grid/circuit.

If you were to do this they may blow each other up since their output is AC and if they don't run in phase they'll burn up; both of them.
You can only do that if you have a means to have them run in phase which I doubt to be on hand for a portable generator.

Normally to run two set in parallel that means they have to be precisely synchronized as to phase and RPM as RPM sets frequency.
Except the Honda's are inverter generators, meaning I believe that they have alternators that make power that is then sent to an inverter that converts it to 60 Hz, regardless of engine RPM.
I don't know the specifics of how its done, but the Honda's are meant to be paralleled, the wiring to do so with instructions comes with the Companion generator, or may be an option, don't remember, but it is a factory kit, no something home made.
Now the extended run kits is a home made thing.
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Old 16-08-2016, 19:15   #19
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Re: Are the BTU's on this Cruisair correct? If so, what genset would support it?

There has been a lot of talk here. But to your question? I think is how many watts do I need to run my A/Cs. To answer, look in the paper work that came with the units or look inside at the data plate and see what the amp rating of the perspective units are, multiply them by the volts supplied and you'll have the watts required. add a couple percent for wire/connections and you'll have a decent real world idea of what size generator you need.

also the hondas have parallel adaptors that work well the yamaha's have them too. inverter generators will keep a set cycle no matter the rpms to a certain degree.
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Old 16-08-2016, 21:04   #20
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Re: Are the BTU's on this Cruisair correct? If so, what genset would support it?

2 questions for you toconsider
I would doubt the Oman would fit in a 40 Ft
Weight it also be too much for the 40ft
2 honda running in sych at night better anchor a looong way awsy from other yachts or you may be target.

I have a 5kva (single cylinder) weight is 82 kg on my 44ft yacht running a 18kbtu unit no problems running or starting . I believe a 5kva could runs 2 units as long as the compressors didn't start at same time.

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Old 20-08-2016, 07:42   #21
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Re: Are the BTU's on this Cruisair correct? If so, what genset would support it?

A single Honda 2000i can just start a 7kbtu a/c unit, so neither the 12k or 16k would work on their own without some added hardware (smart start, inverter assist, or a second generator). A built in generator is easily going to blow your budget by the time you've dealt with installation costs etc.
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Old 20-08-2016, 08:02   #22
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Re: Are the BTU's on this Cruisair correct? If so, what genset would support it?

Rather than looking at BTUs, (the listing is wrong, BTW), look on the label for current consumption in amps. With any luck, both startup and continuous current will be listed.

If there are two AC units you need to realize that they might both start up at the same time so you need a genset that can handle the total startup current plus any additional current that the boat might be using. An electric stove would draw a great deal of current. A water heater will draw quite a bit as well.

You could be baking a roast in the oven, cooking potatoes and a vegetable on two burners, heating water and starting up two AC units at the same time.

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