The Cummins RS20AC Standard Edition is designed to operate down to 0 degrees Fahrenheit out of the box. The generator meets NFPA 37, allowing it to be installed as close to 18 inches from the structure. This unit can provide whole house coverage for many homes, including lights, receptacles, and appliances. Powerful motor starting – starts and runs a 5-ton air conditioner. Includes 200A Service Rated Transfer Switch. Installation Process