SiUS091133 Main FunctionsFunction and Control 341.6 Automatic OperationOutline Automatic Cooling / Heating FunctionWhen the automatic operation is selected with the remote controller, the microcomputerautomatically determines the operation mode as cooling or heating according to the roomtemperature and the set temperature at start-up.The unit automatically switches the operation mode to maintain the room temperature at the settemperature.Detail Ts: set temperature (set by remote controller)Tt: target temperature (determined by microcomputer)Tr: room thermistor temperature (detected by room temperature thermistor)C: correction value1. The set temperature (Ts) determines the target temperature (Tt).(Ts = 18 ~ 30°C, 64.4 ~ 86°F).2. The target temperature (Tt) is calculated as;Tt = Ts + Cwhere C is the correction value .C = 0°C (0°F)3. Thermostat ON/OFF point and operation mode switching point are as follows.(1) Heating Cooling switching point:Tr Tt + 3.0°C (+5.4°F) (FTXS series)Tr Tt + 2.5°C (+4.5°F) (FDXS series)(2) Cooling Heating switching point:Tr < Tt – 2.5°C (–4.5°F)(3) Thermostat ON/OFF point is the same as the ON/OFF point of cooling or heating operation.4. During initial operationTr Ts : Cooling operationTr < Ts : Heating operationFTXS seriesEx: When the target temperature is 25°C (77°F)Cooling 23°C (73.4°F): Thermostat OFF 22°C (71.6°F): Switch to heatingHeating 27°C (80.6°F): Thermostat OFF 28°C (82.4°F): Switch to coolingFDXS seriesEx: When the target temperature is 25°C (77°F)Cooling 23°C (73.4°F): Thermostat OFF 22°C (71.6°F): Switch to heatingHeating 26.5°C (79.7°F): Thermostat OFF 27.5°C (81.5°F): Switch to coolingTarget temperature + 3.0˚C (+5.4˚F)Heating OperationTarget temperature – 2.5˚C (–4.5˚F)Cooling Operation(R16965)Target temperature – 2.0˚C (–3.6˚F)= Thermostat OFFTarget temperature + 2.0˚C (+3.6˚F)= Thermostat OFFTarget temperature + 2.5˚C (+4.5˚F)Heating OperationTarget temperature – 2.5˚C (–4.5˚F)Cooling Operation(R16966)Target temperature – 2.0˚C (–3.6˚F)= Thermostat OFFTarget temperature + 1.5˚C (+2.7˚F)= Thermostat OFF
