What size generator do I need

[The Old Farmers Wife]

Our new, to us, 5th wheel RV did not come with a generator.  What size do I need, to run our a.c.?

 

[John61CT]

How long is a piece of string?

We need the AC unit's size in BTU, how much current it draws while operating as measured by a KillaWatt would be helpful, ideally how much current the maker says it needs at startup (lots more than the previous).

Maybe someone else has the same unit, so at least post the mfg and model.

Do you know about soft-start capacitors?

Also, what other appliances might you want to run, without having to shut down the AC?

Do you use House batteries for extended boondocking? How big in Amps is your charger ("converter")?

 

[tx2sturgis]

Generally speaking a 3000 to 4000 watt genset will do it with some reserve for a few other appliances, if you have a 30 amp service. But you probably have 50 amp service and possibly 2 roof AC units so 4000 might not be enough. In that case you might need something around 5000 or more.

You also need to make sure you get a genset with a compatible RV plug, either 30 amp or 50 amp depending on the shorepower plug that you have.

Look in your owners manual and see what it recommends.

 

[Every Road Leads Home]

How long is a piece of string?

With out seeing it in person, I'd guess it's twice as long as half it's length.

 

[highdesertranger]

look at the breaker for the AC 15A, 20A? and like John said do you want to run other things while the AC is running? give us the size of the breaker. if you can get the data from the AC that will get you the minimum but if you go by the breaker you will have no problems. highdesertranger

 

[bullfrog]

My old Barth motor home has a 50 amp service pole plug and a 7000 watt genset to run 2 13500 btu ACs and a microwave as well as converter.

 

[jimindenver]

I will add that if you plan on running it at high altitude that you need to add 50% more power to make up for the loss in power.

The 3000w range of inverter generators are the most popular for running a single A/C on a rig. After that they start getting pretty big, heavy and really expensive. You have to consider where you will store it and how to move it. Most of the larger come with wheels or you can get a wheel kit for them. Still the 3000w range weigh 100 pounds or more with remote start.

Multiple smaller inverter generators that are linked together are also a option. Easier to lift but twice the maintenance.

Outside of the quieter inverter options would be a open frame generator. They are much less expensive and louder but can be had for around $300 plus some with wheels and remote start. Here again you are looking at 100-120 pounds. The ones I have had were reliable, easy to start, fairly lean power on the 120v only version and could do what the inverter generators can't at my altitude, start my A/C. That said I would not run one around others as they are loud.

So the biggest thing is to figure out how much power you need and where you plan on using it.

 

[rvpopeye]

1 AC =3000-4000 watt gen.=a little extra for other items
2 AC = 6500+ watt gen = a little to a lot extra depending on what size the + is.

Many of the inverter gens have a link option
EX; 2 Honda EU2000i will run 1 AC and then you could run only one for smaller loads.

Gas usage
A Honda 2000 = 5hrs / gal on full load , 15hrs on light load
A Onan 6500 will use 3/4 gallon per hour no matter the load
just to give you a frame of reference.

 

[Scott7022]

I never knew the altitude thing! Thanks Jim!

 

[The Old Farmers Wife]

Our new, to us, 5th wheel RV did not come with a generator.  What size do I need, to run our a.c.?

thanks everone for your input.  This gives me a place to start, as I've said I don't know a whole lot, even though I've camped all my life.  Primitive camping was much easier, but now I'm going for comfort.  And my class C was fully self contained, so just fill the water tanks and I was good to go.  Push button start generator and turn on the propane & I was set.

FYI, RV is only 25 feet, so only 1 ac unit and our power is 30 amp.  I'll check the numbers on the other stuff

We own a generator, but I seems a bit large to be taking RVing.  In our neck of the woods, in SW Kansas, living in the boonies, it's common to loose power with all of our storms

 

[jimindenver]

A champion 3100i or the newer 3400 that will run off of propane or gas would do well and is the least expensive of the big three manufactures. They are a bit louder the the Yamaha and Honda counterparts but are also less than half the cost. They can be had in a remote start unit and have great customer service.

 

[John61CT]

Good pricing and warranty policy through Cosco as well