DETERMINING ELECTRICAL LOAD FOR GENERATOR
Continued
other. For standby service to home or building, only include items you must power.
2.Enter running watts of each item except motors. The light bulb or appliance nameplate lists its wattage. Remember, 1KW = 1000 watts. Note: The name- plate may not list wattage. It may only list volts and amps. The formula for finding wattage is: Volts x Amps = Watts. For example: An appliance name- plate states 3 amps at 120 volts. 3 amps x 120 volts = 360 watts.
3.Electric motors present a special problem. They require up to
4.Add watts and starting watts of all items. This total must not be larger than the rated wattage of your generator. It is a good idea to have up to 25% extra capacity for future needs or extra equipment.
Chart 1
Typical Electric Appliance Wattages
| Running | Starting |
| Running | Starting |
Equipment | Watts | Watts | Equipment | Watts | Watts |
|
|
|
|
|
|
Light bulb (100W) | 100 | 100 | 1/2" Drill | 1000 | 1250 |
Radio | 150 | 150 | Toaster | 1200 | 1200 |
Fan | 200 | 600 | Coffee maker | 1200 | 1200 |
Television | 400 | 400 | Skillet | 1200 | 1200 |
Furnace fan (1/3 hp) |
|
| 14" Chain saw | 1200 | 1500 |
with blower | 600 | 1800 | Water well pump |
|
|
Vacuum cleaner | 600 | 750 | (1/2 hp) | 1000 | 3000 |
Sump pump (1/3 hp) | 700 | 2100 | Hot plate/range |
|
|
Refrigerator/freezer | 800 | 2400 | (per burner) | 1500 | 1500 |
6" Circular saw | 800 | 1000 | 10" Table saw | 2000 | 6000 |
Floodlight | 1000 | 1000 | Water heater |
|
|
|
|
| 5000 | 5000 | |
|
|
|
|
|
|
Chart 2
|
| Approximate Starting Watts* |
| ||
|
|
|
|
|
|
Motor | Approximate | Universal | Repulsion |
| Split |
HP | Running | Motors | Induction | Capacitor | Phase |
Rating | Watts | (small appliance) | Motors | Motors | Motors |
|
|
|
|
|
|
1/8 | 275 | 400 | 600 | 850 | 1200 |
1/4 | 400 | 500 | 850 | 1050 | 1700 |
1/3 | 450 | 600 | 975 | 1350 | 1950 |
1/2 | 600 | 750 | 1300 | 1800 | 2600 |
3/4 | 850 | 1000 | 1900 | 2600 | x |
1 | 1000 | 1250 | 2300 | 3000 | x |
1 1/2 | 1600 | 1750 | 3200 | 4200 | x |
2 | 2000 | 2350 | 3900 | 5100 | x |
3 | 3000 | x | 5200 | 6800 | x |
* – Always use starting watts, not running watts, when figuring correct electrical load.
x – Motors of higher horsepower are not generally used.
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