Portable gasoline generators, Determining electrical load for generator – Desa PGH7500IE User Manual
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PORTABLE GASOLINE GENERATORS
Running
Starting
Equipment
Watts
Watts
1/2" Drill
1000
1250
Toaster
1200
1200
Coffee maker
1200
1200
Skillet
1200
1200
14" Chain saw
1200
1500
Water well pump
(1/2 hp)
1000
3000
Hot plate/range
(per burner)
1500
1500
10" Table saw
2000
6000
Water heater
(storage-type)
5000
5000
Running Starting
Equipment
Watts
Watts
Light bulb (100W)
100
100
Radio
150
150
Fan
200
600
Television
400
400
Furnace fan (1/3 hp)
with blower
600
1800
Vacuum cleaner
600
750
Sump pump (1/3 hp)
700
2100
Refrigerator/freezer
800
2400
6" Circular saw
800
1000
Floodlight
1000
1000
for motors, you must use the starting
watts figure. Do not use the running
watts figure.
Note:
Some motors re-
quire nearly the same wattage to run as
to start. These items include saws,
drills, hair dryers, and food mixers. See
Chart 1 for typical appliance wattage
examples.
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.
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
Chart 2
* – Always use starting watts, not running watts, when figuring correct electrical load.
x – Motors of higher horsepower are not generally used.
Chart 1 - Typical Electric Appliance Wattages
DETERMINING
ELECTRICAL LOAD
FOR GENERATOR
You must decide what electrical load your
generator can power. Do this before using
generator. Use the following four-step
method. It will help you select a load that is
not too large. Make sure total wattage of all
electrical loads does not exceed rated watt-
age of generator. For rated wattage of your
generator, see Specifications, page 5. Elec-
tric motors present a special problem when
figuring load. Read Step 3 carefully.
1.
Make two lists of items you want pow-
ered by generator. List all motors and
motor powered appliances in one. List all
lights, small appliances, etc. in the other.
For standby service to home or building,
only include items you must power.
2.
Enter running watts of each item ex-
cept 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
nameplate states 3 amps at 120 volts. 3
amps x 120 volts = 360 watts.
3.
Electric motors present a special prob-
lem. They require up to three-times
their rated wattage to start. Chart 2,
below, shows starting watts for differ-
ent size motors. For example: an elec-
tric motor nameplate states 5 amps at
120 volts. 5 amps x 120 volts = 600
watts running. Multiply this figure by
3. This will show the starting watts
needed. 600 watts x 3 = 1800 watts to
start. When figuring the generator load