Generator sizing: We recommend the generator size based upon the home square footage area and the number of 240 volt appliances . Homes between 0 - 1500 sq. ft. with (3) 240 volt appliances can use a 14 kW generator to supply power for minimum lighting and appliance operation. Recommend running (1) one 240 volt appliance of 40 amps or less for short durations for better efficiency. Check with a licensed electrician for your specific needs.