What size generator?

[kcsairstream]

I have a 1979 31'sorveign with one coleman air conditioning and a working battery charging system. What is the best largest generator for running the AC,TV,microwave,coffeepot, lights, and a fan. And the best smallest generator without the AC running. I tried a 1200 watt generator and it would not work kept tripping the generator breaker without using the AC I was only running a fan,lights, and of course the battery charging system. Would like to know what is the best generator size for the least amount money to fully operate my airstream that has a smart throttle and is quiet running. Would also like to know what size solar panel needed to keep refrigerator running and batteries charged.

Thank You,kcsairstream

[azflycaster]

The 1200 should have been enough for charging the battery and a few other items. I use a 1000 for that with no problems.

If you want to run the AC, microwave and a coffee pot (all at the same time) you are going to need a lot of watts.

[TinLoaf]

A lot of folks are going to recommend that you get two Honda 2000s. That's far from a low cost solution. I had a 3000 watt Kipor which is very similar to the Honda 3000. It was quiet and effective, but very heavy (140 lbs). I lost the Kipor in a fire and decided to go with the Yamaha 2400. It was only $200 more than a Honda 2000 and I felt that was worth the extra cost for the chance that it would run my A/C.

The Yamaha 2400 is 70 pounds and runs my trailer and A/C comfortably. However there are a lot of unknowns in your situation. How big is your A/C? How old? The Yamaha 2400 is only advertised to run "most newer 13,500 btu a/c". Even if it does work you still won't be able to run the coffee pot or microwave at the same time the A/C is running.

Since your A/C is probably older your cheapest solution may be a 3000 watt unit but you'll pay for it in weight.

There's one guy on the forums that will surely chime in with a list of 10 threads showing that this has been discussed before and that you should have used the search tool. Just ignore him, and welcome to the forums!

[utee94]

Hey Tinloaf-- Search tools aside, how did you like the Kipor? It's certainly less expensive than the similarly rated Hondas and Yamahas-- is the main drawback weight, or are there other negative aspects you found?

Also, how well have you found the Yamaha 2400 to run your AC systems? Do you ever feel like you are overloading it?

Like KCAirstream, I am looking for something that can run the AC on my trailer (and as many other systems as possible, but I'm okay with only running AC and a few lights if that's all it can do). I know it will depend on the AC, in my case I have a new Carrier AirV low-profile 15K BTU.

I know that twin 2000s will do it, but I'd really love to find a less expensive solution.

-Marcus

[dogpound]

Based on a lot of research on most of the top name generators we went with a Yamaha 3000 with a surge on it whenever a large load hits it. Granted you have to suffer for the the weight but if you are going to run what most of these new units have on them you need a larger generator. Our unit was a little over $2,000 but it has electric start and an economy function if all you are doing is charging the battery. I am still looking into the solar panels. My unit is wired for solar but it was not on the unit when it came from the factory.

Welcome to the forum and hope you find what you need.

Bob

Member of Four Corners Unit

[TinLoaf]

Originally Posted by utee94

how did you like the Kipor?

I just got the Yamaha earlier this year and haven't had too much time to test it. I powered up the A/C in the driveway for a few hours during the break-in period and it didn't sound like it revved up much more than idle. I was very impressed. I thought it would be screaming, but it was quiet and controlled. I turned on all the lights in the trailer plus the TV and it didn't make a difference.

I got the Kipor a few years ago when the 3000 watt model was $899 shipped to your door. I was going to get another one but now they are almost as much as the equivalent Honda so it's not the bargain it once was. It was as quiet as the new Yamaha and ran a/c and microwave at the same time. It had the smart throttle and everything. I had two seasons of pretty heavy use and it never failed me - even at 15 degrees. The longevity of the Kipor is yet to be proven.

Originally Posted by utee94

Carrier AirV low-profile 15K BTU

I'm pretty sure you'll need 3000 watts for the 15,000 BTU a/c.

[purman]

If all I need to do is run a coffee maker and charge batteries and some other small stuff. Don't think i will use a microwave can I get by with a Honda 1000?????

[TinLoaf]

Originally Posted by purman

If all I need to do is run a coffee maker and charge batteries and some other small stuff. Don't think i will use a microwave can I get by with a Honda 1000?????

Absolutely. If you want to run the microwave I'd consider the Honda 2000. That's what I was originally planning to do, but then I decided that I'd spend the extra $200 and get the Yamaha 2400 in case I needed to run the a/c on a summer road trip. My plans kind of snowballed.

[thecatsandi]

Originally Posted by purman

If all I need to do is run a coffee maker and charge batteries and some other small stuff. Don't think i will use a microwave can I get by with a Honda 1000?????

No that will not work. A Honda 2000 will run a microwave. A 1000 won't run a hair dryer. Even with 2000 you need to load manage. A coffee maker when making coffee uses a lot of power.

[Jim Foster]

We use an older Honda 1000 which I bought used some years ago. It will run our microwave (950w), it will run our espresso maker (900w). Most microwaves and coffee makers draw more than our units. The wattage draw is usually stamped, cast or printed on the back or bottom of the unit.
Our boondocking us usually in the cooler months, so running the A/C on a generator is not an issue.
That being said, when our little Honda dies, I will probably replace it with a Honda 2,000.

[mustang]

Hello. You need at least 4000 watts for A/C
Good Luck

[mustang]

PS: I always use a 5000 watt or more. I can run micro and A/C.

[utee94]

Always see a little bit of conflicting information here. So let's take a look at some numbers:

For my Carrier AirV 15KBTU, the max current is 14.1A and the max power consumption is 1582W based on a nominal 115VAC.

The Honda 2000i specs say it can operate at a maximum of 2000W and 16.7A, while its rated power and current are 1600W and 13.3A. Now, according to the Honda's max specs, it should be able to operate my A/C alone, by itself, near the generator's max capability. Now I certainly prefer some margin, so I can acknowledge that the 2000 is really not up to this task, especially if you want to operate ANYTHING else in the trailer.

So taking a look at the Honda 3000, I see the following: Max Power 3000W, 25A. Rated Power 2800W, 23.3A. Now, at rated power, this unit still exceeds the max power consumption specs of the A/C unit by a substantial margin. So in theory the 3000 should be able to run the A/C, and just about as many lights as you want, all at the same time. I could see that it might have an issue if you're trying to run the A/C, a microwave, and a hair dryer all at the same time. In that case, I suppose I would kill the A/C until the other tasks were completed.

Then there's the Yamaha 2400. This one is spec'd at 2400W/20A Max Power, and 2000W/16.7A Rated Power. So it should also be able to run the A/C plus a few lights at its Rated specs, without even hitting the Max specs, although obviously with less margin than the Honda 3000 has.

So that's the theory, on paper.

In reality, I'm wondering what empirical evidence the wise and experienced members of this Forum have that shows that you really need considerably more power than the Yamaha 2400 can provide, and even more than the Honda 3000 can supply?

Thanks in advance!

-Marcus

[mustang]

Utee this is the same old question. However Inland Andy crunched some numbers. Keep in mind if you run lean on the compressor you will shorten its life. That cant be argued, however, Posted previously and numbers crunched came in somewhere around 3600 for your unit alone if I remember carrectly. Factoring a safety 4000 is a safe bet. Anything less is simply just to hard on the systems. Adding the expense of replacement.

Becarefull not to cook your compressor. The R/V dealer has always told me 5000 watts because it is best to have a 30 amps to plug into.

Just thought I would comment,

[richinny]

the start load of the ac is much higher that the wattage listed. i think someone (lewster?) posted some numbers. low voltage is a very bad thing for your ac.

[richinny]

what some do, and what one should do, sometimes conflict.

here is the post from inland andy:
http://www.airforums.com/forums/show...61&postcount=2

note that is is for a 13.5 btu ac.

[utee94]

Thanks for the input guys.

But then I cannot help but wonder why the A/C manufacturers don't list these additional requirements on their spec sheets?

For those who don't know, I'm an electrical engineer, though of the microprocessor variety. Still, we're forced to spec everything. Max rating should include startup and/or inrush current, and obviously power consumption would be based on that current multiplied by your actual voltage.

Also, at the "Rated" power consumption spec on the generator unit, I would not expect any voltage sag. I would expect to see some voltage sag when you are running near Max spec, but at Rated power the genny should be able to supply the full load specified at the voltage specified.

So, are people in the field actually seeing voltage sag on their gensets even when operating at the Rated spec, which is well below the Max spec?

[utee94]

Originally Posted by richinny

what some do, and what one should do, sometimes conflict.

here is the post from inland andy:
http://www.airforums.com/forums/show...61&postcount=2

note that is is for a 13.5 btu ac.

With all due respect to Andy, on that particular post, I believe he misunderstood the OP. The OP was asking about an inverter-style generator, rather than an inverter. I would certainly never consider running an RV A/C unit from a standard inverter using standard deep cycle batteries.

Also, the spec sheets only show about a 5% difference between the 13.5K BTU and 15K BTU models for max power and max current, so I suppose we could roughly estimate the same 5% difference for startup current/power...

[richinny]

Originally Posted by utee94

With all due respect to Andy, on that particular post, I believe he misunderstood the OP. The OP was asking about an inverter-style generator, rather than an inverter. I would certainly never consider running an RV A/C unit from a standard inverter using standard deep cycle batteries.
Also, the spec sheets only show about a 5% difference between the 13.5K BTU and 15K BTU models for max power and max current, so I suppose we could roughly estimate the same 5% difference for startup current/power...

you're right it wasn't the post i remembered but it had some useful info.

as for the surge rating on the ac units....that would be nice.
as for a surge rating on generators, i've seen them.

i'll wait for lew now :-) since he fixes them!

[utee94]

Originally Posted by richinny

you're right it wasn't the post i remembered but it had some useful info.

as for the surge rating on the ac units....that would be nice.
as for a surge rating on generators, i've seen them.

i'll wait for lew now :-) since he fixes them!

Thanks for your input, of course. And this is precisely why I asked the question about empirical data.

If I can't believe what's on the spec sheets, well, I have absolutely no other basis for analysis.