Guardian® emergency standby generators, with a range of 7kw - 16kw. GUARDIAN® air-cooled generators offer the most wattage and greatest starting power in their class. The GUARDIAN 16 kW can start a 5-ton and 3-ton A/C unit or two 4-ton units. The 13 kW can start a 4-ton and the 10 kW can start a 3-ton. (May not start all brands or models of central air conditioners. Make sure the surge capability (Amps) of the generator is greater than the LRA listed on the data plate of the A/C before purchasing.)