GENERATOR WATTAGE CALCULATOR
Depending on how you will use your generator, there are different categories to
meet your needs. This can include recreation, home standby and construction. Honda
also offers Inverter Generators. Inverter generators are smaller and lighter as
power is created electronically and not through a conventional alternator. Inverter
power offers the cleanest power output, ideal for sensitive electronic devices.
If you want a generator for home standby, for example, if you want to run your refrigerator,
youll need at least 2500 watts or more. And if you want to use a
transfer switch so that power can go directly into your home, youll want
a generator with at least 3000 watts.
Youll also need to consider the maximum and rated power of the generator. This is
important depending on what items you want to run off of your generator. Items such
as toaster, lamps, and coffee makers are resistive, or constant loads and their
total load can be calculated at amps x 1. Items such as saws and drills are reactive
loads and while the running load may be small, the starting load should be calculated
at running amps x 3. Remember, after the intial start less power is required for
actual operation.
Always remember that simple power management will allow a smaller generator to do
a big job. Very seldom are all tools or appliances operating simultaneously. When
calculating power requirements, consider the starting requirements are only for
the initial start and then additional tools may be operated in addition.
Remember Ohms Law from High School Physics?
Watts = Volts x Amps
Amps = Watts/Volts
So if you have two of the numbers (e.g. volts, amps) then you can find out the other
(e.g. watts). This can help you to determine the rated power that youll need from
your generator.
AVERAGE WATTAGE REQUIREMENT GUIDE
(AMPS X VOLTS = WATTS)
|
Household
|
Approximate
Wattage Required
For Starting
|
Approximate
Running Wattage
Requirements |
Coffee Maker
|
600
|
600
|
Dishwasher
Cool Dry |
540
|
216
|
Electric Fry Pan |
1500
|
1500
|
Electric Range
8-inch element
|
2100
|
2100
|
Microwave Oven 650 watts
|
1000
|
1000
|
Refrigerator or Freezer Energy Star
|
1200
|
132-192
|
Automatic Washer
|
1200
|
1200
|
Clothes Dryer
Electric
|
6750
|
5400
|
Furnace Fan, gas or fuel oil
|
1/8 Horsepower |
500
|
300
|
1/6 Horsepower |
750
|
500
|
1/4 Horsepower |
1000
|
600
|
1/3 Horsepower |
1400
|
700
|
1/2 Horsepower |
2350
|
875
|
Incandescent Lights |
as indicated on bulb
|
as indicated on bulb
|
Radio
|
50 to 200 |
50 to 200
|
Sump Pump
|
1/3 Horsepower |
1300
|
800
|
1/2 Horsepower |
2150
|
1050
|
Television - Color
|
300
|
300
|
Air Conditioner
10,000 BTU |
2200
|
1500
|
Contractor
|
Approximate
Wattage Required
For Starting
|
Approximage
Running Wattage
Requirements |
Air Compressor
1 Horsepower
|
4500
|
1600
|
Bench Grinder
8 inches
|
2500
|
1400
|
Hand Drill
1/2 inch
|
900
|
600
|
High-pressure Washer
1 Horsepower
|
3600
|
1200
|
Circular Saw, Heavy Duty
71/4 inches
|
2300
|
1400
|
Electric Chain Saw
14 inches, 2 Horsepower
|
1100
|
1100
|
Table Saw
10 inches
|
4500
|
1800
|
Drills
|
3/8 inch 4 amps
|
600
|
440
|
1/2 inch 5.4 amps |
900
|
600
|
Industrial Motors
|
Approximate
Wattage Required
For Starting
|
Approximage
Running Wattage
Requirements |
Split Phase
|
1/4 Horsepower |
1700
|
400
|
1/2 Horsepower |
2600
|
600
|
Capacitor Start Induction Run
|
1/3 Horsepower |
975
|
450
|
1 Horsepower |
2300
|
1000
|
Capacitor Start Capacitor Run
|
1 1/2 Horsepower
|
4200
|
1600
|
Fan Duty
|
1/4 Horsepower |
1200
|
650
|
Farm Equipment
|
Approximate
Wattage Required
For Starting
|
Approximage
Running Wattage
Requirements |
Electric Fence, 25 miles
|
250
|
250
|
Milk Cooler
|
1800
|
1100
|
Milker (vacuum pump),
2 Horsepower |
2300
|
1000
|
Portable Heater (kerosene, diesel fuel)
|
50,000 BTU
|
600
|
400
|
90,000 BTU |
725
|
500
|
150,000 BTU |
1000
|
625
|
Battery Charger
|
15 amp |
380 |
380
|
60 amp with 250-amp boost
|
1500/5750 |
1500/5750
|
100 amp with 300-amp boost
|
2400/7800
|
2400/7800
|
Electric Welder
|
200 amp AC
|
9000 |
9000
|
230 amp AC, at 100 amp |
7800 |
7800
|
Air Compressors |
Approximate
Wattage Required
For Starting
|
Approximage
Running Wattage
Requirements |
1/2 Horsepower |
1600
|
975
|
1 Horsepower
|
4500 |
1600
|
Computers
|
Approximate
Wattage Required
For Starting
|
Approximage
Running Wattage
Requirements |
Desktop
|
600 to 800 |
600 to 800
|
Laptop
|
200 to 250 |
200 to 250
|
Monitor (CRT)
|
200 to 250 |
200 to 250
|
Fax
|
600 to 800 |
600 to 800
|
Printer |
400 to 600 |
400 to 600 |
|