How large of a generator should you order? 

Consulting the form below will give you a good indication. We usually recommend that you add 25% to whatever it is that you need now for future power requirements.  The wattage listed below are approximates and is meant to give you a general idea of your power requirements. Consult a certified electrician before making a final determination. 

When determining the required kW, remember that 1,000 watts equal 1kW, 2,000 watts equal 2kW and so on. The formula for finding wattage is Amps x Volts = Watts.  An example would be, if an appliance name-plate states 5 amps at 120 volts then  5 x 120 = 600 watts.

Appliances and machinery that use electric motors present a special problem.  All electric motors require three (3) times to ten (10) times its normal running watts just to start them and the generator must be sized to these starting watts.  Code G motors are the easiest electric motors to start. Starting amps are usually three (3) times motor name-plate amps. Typical examples: furnace or fan blower motors, refrigerators and jet type water pumps.

Code L, M, N motors are extremely hard to start and starting amps are usually six (6) to ten (10) times the motor name-plate rating. Typical examples are air compressors, air conditioners and underground water pumps.

Safe determination of sizing motor loads.

1. Determine code letter found on the motor name-plate.
   2. Determine the horsepower of the electric motor.
   3. Wattage required is found at the intersecting point on the chart.
   4. Add the total number of watts and enter it in the electric motor load box on the form below.

Remember that all these figures are estimates and will vary depending on the particular manufacturer of the appliance that you use. We hope that this form was helpful to you and if you have any other questions or need additional information please do not hesitate to send us an email on the Contact Us page or call us directly at 1-800-723-3334.