Things You'll Need:
- all of the appliances/electrical components that will take power from the generator, and a calculator.
-
Step 1
Electrical power consumption and production is measured in watts. All electrical devices consume power when on, and usually the wattage of any electrical device is labeled somewhere on that device.
-
Step 2
Gather all of the electrical devices that will be taking power from your generator. To provide an example, let's say you have 10 light bulbs, a George Foreman grill, a toaster oven, a microwave, a TV, a radio, and a refrigerator that you plan to use.
-
Step 3
One by one, find and note the wattage of each item. It will be written as a number followed by a "W" or for larger appliances, possibly a "KW", meaning kilowatts. The wattage of the device, along with other pertinent information such as voltage, should be marked somewhere. It is normally located on a sticker in the case of appliances. The location of this sticker may vary. It is usually found underneath the device or at the rear; often it can also be found attached to the power cord.
-
Step 4
So, continuing our example, you find that 5 of the 10 light bulbs are 60W, and 5 are 40W for a total of 500W (60+60+60+60+60+40+40+40+40+40); the Foreman grill is 800W; the toaster oven, 1500W; the microwave, 1000W; the TV, 125W; the radio, 13W; and the refrigerator, 175W.
-
Step 5
Now, add all of that up: 500+800+1500+1000+125+13+175= 4113W. This is the total power consumption of all of your appliances. Now, assuming that there is a chance that you might be running all of these appliances at any time, you'll need a generator that generates at least 4113 watts of power.
-
Step 6
One thing to consider, however, is the types of appliances that will draw power from the generator. Most of the appliances in the example are simple appliances, such as lights, meaning that they consume a relatively steady amount of power. For some, like the toaster oven and microwave, the power consumption can vary. The microwave, and appliances like it that have adjustable power settings, will consume power according to the power setting you apply. The fridge, however, is a whole other animal, since it has a motor. Appliances and tools with electrical motors, such as circular saws, drills, washing machines, dryers, etc., will vary greatly in power consumption. This is most notable upon starting up a motor or putting the motor under heavy load (such as when a circular saw is cutting through tough wood). Power consumption can spike 200 to 300 percent under these circumstances.
-
Step 7
This changes things a little. If the fridge normally runs at 175W, this means upon start-up (i.e. - each time it begins it's cooling cycle) its power consumption may spike, reaching 350W to 525W for a split second. So, at any given time, the power consumption could reach a total of 4463W.
Make sure to take into account this possibility for any appliances with sizable electric motors, and add the adjusted wattage to the total. -
Step 8
Once you've added up the power requirements for all of your appliances, and taken into account those appliances that may have power spikes, you can determine the size of the generator you need. In this case, where we may be consuming up to 4463W at any time, a 5000W generator should do the job.
