How big a generator would I need to run a 110v Refrigerator, TV, VCR and an Air Conditioner in my motor home? I can buy this: Craftsman generator 2400-watt, like new, $200. Would this be big enough?
ANSWER: Hi Don, I am not the bearer of good news, based on what you are going to be powering in your RV, I do not believe that a 2,400 Watt generator is going to be sufficient for your needs.
Let's start by evaluating the wattage usage of the appliances you are planning to use.
Refrigerator A standard Absorption Cycle RV fridge, depending on size, uses anywhere between 400 to 1000 watts of electricity. The majority of RV refrigerators use heat to cause a chemical reaction to cool down the fridge. The heat is either provided by Propane or a 110-volt electrical heating element.
The way you phrased your question made it sound like you are possibly using a home style refrigerator in your RV. A home fridge uses a 110-volt compressor to create the cold. When you use a refrigerator with a compressor, you not only have to worry about how many Watts it uses when running, but it takes 2 to 3 times the wattage to start the compressor every time the fridge cycles the compressor on and off. A small Home type Fridge can use anywhere from 400 to 1000 watts. A larger fridge/freezer combination can use 1000 to 2400 watts.
Air Conditioner An air conditioner uses a compressor to create the cold, so it will also use 2 to 3 times more wattage as the compressor cycles on and off. You can expect an A/C unit to use anywhere between 1,400 to 2,400 watts.
Other Items TV depending on size 200 - 600 watts. VCR 150 - 200 watts. Here are some other items that you may want to use when camping; Microwave 1,000 watts, Coffee Maker 900 watts, Toaster 1,150 watts and Hair Dryer 1,000 watts.
Just using the minimum wattage for the 4 items you mentioned, the total wattage comes out to 2,150 watts, and that is not including the start-up wattage of the compressor on the A/C. It is also assuming that you have an absorption-type RV Fridge. If you use the Microwave or Coffee Maker or Toaster or Hair Dryer while using your other electrical items, you will exceed the generator's 2400 Watt Rating.
The bare minimum size generator I would suggest you use is a 3,500 Watt generator, and that might even be cutting it close. For just a little over $100.00 more than what you are paying for the used generator you are looking at, you can get a brand new portable generator rated at 3,500 watts or greater. Buying new also has the advantage of having a manufacturer's warranty.
The video below explains how to calculate what size generator you need to run different types of appliances.
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