What's What With Wattages?

Generators are available anywhere from 900 watts to 100 KW+. How much juice you'll need is the most important aspect when deciding on a generator model. Mismatched workload and power output can be catastrophic.

The first thing we must realize when gauging appropriate wattage and workload is that there are two separates figures we will be working with. One figure is the amount of juice needed to run the appliance consistently. The other is an initial startup charge (surge wattage), which is considerably higher than the run figure (sometimes reaching double the running wattage). For example, a small fan could take 300 watts to run but 500 to start. You need to do a little arithmetic to get things running smoothly. Because of the large intake during start up, you may need to turn off some appliances before plugging in others.

Another point to mention is that many appliances are rated in amps (amperes). Generators work with watts, however. So, again, math is required, but don't worry, not too much. Basically, you need to multiply the volts times the amps. For example, a laptop could have an output of 16.5V and 3.6A. This would require roughly 60 watts to run.

Additionally, adding more to the grand total is a good idea as different brands and makes of the same appliance can vary as much as 20%. Finally, you don't want to be running on full load and leave yourself with 0 breathing room. Adding another little bit is advised for this reason (especially since many models are designed to automatically shut off when they reach nearly full to preserve the engine and wiring.)

Now for a little translation (physics, arithmetic, foreign language, you're getting a full university education here!) When companies write max output level this does not mean you can run your gen. at this level the entire time and be ok. The maximum output level is for initial power ups and limited short-term usage. Your generator will not perform at this level for a long period of time.

It's important to bear in mind when making these calculations that a generator is not meant to restore you to full system power. Keep in mind that this is in the event of a power outage or natural disaster, and a little self-sacrifice may be necessary (sorry, but you may have to hold off on running the central air full blast if the family also wants hot showers).

This chart will give you the approximate needed wattages for many of the appliances you will be running off your electric generator. These are not exact figures, and calculations should be made accordingly.

Air conditioner:	Â	Clothes iron	1400
Central	5000	Light bulb:	written on bulb
Room	1000	Incandescent	100
Clock radio	10-200	Compact fluorescent	25
Coffeemaker	850-1750	Microwave oven	800-1500
Clothes washer	425	Personal computer:	Â
Clothes dryer (electric)	3400	CPU+Monitor	125
Dishwasher	1800	Laptop	25-150
Dehumidifier	1800	Stereo	250
Electric blanket	80	Refrigerator	725
ELectric range	4500	Sump pump	600
Fans:	75-300	Television (color):	Â
Ceiling	120	20" (LCD)	65
Windows	150	26" (LCD)	110
Furnace	750	36-42" (Plasma)	250
Whole House	500	50-60" (Plasma)	340
Freezer (standing)	600	Toaster	1100-1750
Hair dryer	800-1700	Toaster oven	1225
Heating:	Â	VCR/DVD	25
Central, gas furnace	400	Vacuum cleaner	1225
Central, oil furnace	1500	Water heater (electric)	5000
Electric, portable	1125	Well pump	700