Trannergy SGN 1.3kW 1PH Inverter incorporates an input power limiting device, which automatically keeps the power at levels that are safe for the inverter. The limitation depends mainly on internal and ambient temperatures. The limitation is calculated continuously and always allows the maximum possible amount of energy to be produced. The selection of PV string output should be based on the optimum utilization of the invested capital compared to the expected annual energy yield from the system. This optimization depends on local weather conditions and should be considered in each individual case. To ensure the functiona1ity of the DC-switch, a11 switches shou1d be switched on and off (by turning the switch to on and off positions ten times) once a year, to c1ean the contacts.