Control Specification SiBE04-30248 Function and Control3.3 Controls at Mode Changing / Start-up3.3.1 Preheating OperationOutline Operate the inverter in the open phase operation with the conditions including the preheatingcommand (only for heat pump model) from the indoor, the outdoor air temperature anddischarge pipe temperature.Detail Preheating ON Condition When outdoor air temperature is below 10.5ºC and discharge pipe temperature is below10.5ºC, inverter in open phase operation starts.OFF Condition When outdoor air temperature is higher than 12ºC or discharge pipe temperature is higherthan 12ºC, inverter in open phase operation stops.3.3.2 Four Way Valve SwitchingOutline ofHeatingOperationHeat Pump OnlyDuring the heating operation current must not be conducted and during cooling and defrostingcurrent must be conducted. In order to eliminate the switching sound (as the four way valve coilswitches from ON to OFF) when the cooling is stopped, the delay switch of the four way valvemust be carried out after the operation stopped.Detail The OFF delay of four way valveEnergize the coil for 150 sec after unit operation is stopped.3.3.3 Four Way Valve Operation CompensationOutline Heat Pump OnlyAt the beginning of the operation as the four way valve is switched, acquire the differentialpressure required for activating the four way valve by having output the operating frequency,which is more than a certain fixed frequency, for a certain fixed time.Detail Staring Conditions1. When starting compressor for cooling.2. When the operating mode changes from the previous time.3. When starting compressor for rushing defrosting or resetting.4. When starting compressor for the first time after the reset with the power is ON.Set the lower limit frequency to 66 (model by model) Hz for 45 seconds with the ORconditions with 1 through 4 above.3.3.4 3 Minutes Stand-byProhibit to turn ON the compressor for 3 minutes after turning it off.(Except when defrosting. (Only for Heat Pump Model).)3.3.5 Compressor Protection FunctionWhen turning the compressor from OFF to ON, the upper limit of frequency must be set asfollows. (The function must not be used when defrosting (only for heat pump model).)FCG 3FCG 2FCG 1TCG 1TCG 2TCG 3949650240240120