Generac 4583 Ultra Source 17,500 Watt Portable Generator (Discontinued by Manufacturer) 17,500 watt portable generator with enough power to run 5-ton A/C unit Powered by 992 cc Generac OHVI V-Twin industrial-grade engine 16-gallon fuel tank provides 10-hour run-time at half-load capacity Includes pre-wired 16-circuit, 60-amp indoor rated manual transfer switch, power cord, and outdoor connection box 49-by-31-by-39-inches at 525-pounds; 2-year limited warranty