30 amps on an RV (I have a fifth wheel trailer) is at 120 volts, not 240 volts. Some newer high end RV's have 50 amp service, which is 240 volt. 30 amps at 120 volts is 3600 watts; allowing for some power factor a 4kVA generator should be plenty big enough to run everything. A lot of people run air conditioners on the Honda and Yamaha 3000 watt inverter type generators. An air conditioner on a 20 amp circuit should only draw 16 amps (80% of breaker rating)under full load, which is 1920 watts (ignoring power factor). The issue comes in when you try to start the air conditioner, and the generator doesn't have enough surge capacity. You can fix that with a soft start kit for your air conditioner (see your local RV dealer if you have a problem starting the AC on the generator). Once its running it doesn't take that much power to keep it running. One thing to keep in mind when buying a non-RV generator is that the rated output is at 240 volts, which means you can only draw half the rated power at 120 volts. Some of the newer generators come with a provision to put the windings in parallel rather than series, which gives the full output at 120 volts. I saw this feature on one of the e-cheapo Chinese knockoff generators at Costco not too long ago. The bigger generators like you see on motorhomes typically have two 120 volt output circuits. I had an older motor home with a 6.5 kW Onan. It had two 120 volt circuits, and ran one air conditioner off of each one. We could only run one air conditioner at a time (switch selectable) on shore power, which was a 30 amp, 120 volt circuit. The Honda & Yamaha generators are nice, but really expensive. Some of them also have electric start. I have an older 750 watt Honda that will run everything in the trailer except the microwave and air conditioner, and you can't hardly hear it running. Some day I'll get a real RV generator! We also have one of the Lowes special 5.5 kW generators, which runs everything of off one side of the 240 volt output just fine but is way too noisy to use in a campground. For camping we use it mostly on our land in the mountains where we're quite a distance from the nearest neighbor, and then only when we need the air conditioning or microwave. If you really want to research generators, go to RV.net and read some of the threads on the tech board. There's one that addresses these Chinese knockoff generators thats several hundred posts long. Believe it or not, most people who have them are happy with their performance, and they appear to be a great cheap alternative if you're not using it day in & day out. Have no personal experience with them, though. One final bit of advice, don't count on a bigger muffler to bring the noise level down very far. A lot of the noise from these generators is mechanical, not from the exhaust. That's why the really quiet ones are fully enclosed. Keith
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