There are two wattage ratings on Generator, what do they mean and which one do use?
All Generators have rated outputs in both running and surge watts.
The running wattage listed (the lower number) is what the Generator will support as a continuous load. This is the correct number to use when sizing your desired machine. Add up the running wattage from all your desired appliances and compare this number to the Generator's rated running watts. As long as this number is less than the Generator's rated running watts it will handle your desired load.
The surge wattage listed (the higher number) is what the Generator will support as amomentary load. The surge watts allow for the brief extra draw created by many products when they start.
Surge wattage is an important factor for your generator. Most appliances or tools like your refrigerator or circular saw use a/c electric motors. These motors all require a brief high electrical load to start turning.This momentary draw can be two (or more) times greater than the running wattage of that product!
To be safe, add in a bit of "wiggle room" when sizing your Generator. Just because the running watts of all items you want to power is less than the rated running watts of the Generator doesn't mean that all can be used at the same time.
For example, if you want to run (2) 1500 watt refrigerators (total 3000 running watts), and you have a 3000 running watt/4000 surge watt Generator it will technically support these two units. The problem comes in during the "startup load "for these refrigerators. If these refrigerators draw twice their running load at startup (3000 watts each) then you will exceed the Generator's Surge wattage rating by 2000 watts and the Generator will likely shut down.
If you will be maxing out your generator's rating, it's better to buy the next size up!
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