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. Most 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 does not include 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 Coffee Maker 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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