Application Chart for Determining Electrical Load for Generator

Remember 1 kW = 1000 watts 2 kW = 2000 watts and so on

The formula for finding wattage is: Volts x Amps = Watts

Example: an appliance nameplate states 3 amps at 120 volts. 3 amps x 120 volts = 360 watts

Typical Electrical Appliance Wattages

Application/
Equipment

Running/
Rated Watts

Starting/
Surge Watts

Light Bulb (100w)

100

100

Radio AM/FM

50-200

50-200

Radio, CB

50

50

Fan

200

600

Television

300-400

300-400

Microwave Oven

700

1000

Air Conditioner (12,000 BTU)

3250

5000

Furnace Fan (1/3 hp blower motor)

600

1800

Vacuum cleaner

600

750

Sump pump (1/3 hp)

700

2100

Refrigerator/freezer

800

2400

Deep Freezer

500

1500

Circular saw

1000-2500

2300-4600

Circular saw 6"

800

1000

Floodlight

1000

1000

Drill 1/2" Electric

1000

1250

Toaster

1200

1200

Coffee maker

1200

1200

Skillet

1200

1200

Chain saw 14" Electric

1200

1500

Water well pump (1/2 hp)

1000

3000

Hot plate/range (per burner)

1500

1500

Table saw 10"

2000

6000

Water heater (storage type)

5000

5000

12V DC Battery Charger

120

120

 

Electric Motor Wattage Usage

Electric motors present a special problem. They require up to three times their rated wattage to start.

Example: an electric motor name plate states 5 amps at 120 volts, 5 amps x 120 volts = 600 watts.

Multiply this by 3. This will show the starting watts needed. 600 watts x 3 = 1800 watts to start.

Some motor name plates will show starting watts higher in some case 9 times higher, check the name plate.

Approximate Starting Watts *

Motor HP Rating

Approximate Running Watts

Universal Motors (small appliances)

Repulsion Induction Motors

Capacitor Motors

Split Phase Motor

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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