Main Functions SiENBE12-62070 Function and Control1.4 Fan Speed Control for Indoor UnitsControl Mode The airflow rate can be automatically controlled depending on the difference between the settemperature and the room temperature. This is done through phase control and Hall IC control.For more information about Hall IC, refer to the troubleshooting for fan motor on page 216.Phase Steps Phase control and fan speed control contains 9 steps: LLL, LL, SL, L, ML, M, MH, H and HH.= Within this range the airflow rate is automatically controlled when the FAN settingbutton is set to automatic.Note: 1. Fan stops during defrost operation.2. In time of thermostat OFF, the fan rotates at the following speed.Cooling : The fan keeps rotating at the set tap.Heating : The fan stops.Automatic AirFlow Control forHeatingOn heating mode, the indoor fan speed will be regulated according to the indoor heat exchangertemperature and the difference between the room temperature and the required set point.Automatic AirFlow Control forCoolingThe following drawing explains the principle of fan speed control for cooling:FTXG25/35EATXG25/35E CTXG50EATXG50E FTK(X)S50EATX50E FTK(X)S20-50DATXS20-50EFTK(X)S20-35CAATXS20-35DAFDK(X)S25-35EAFDK(X)S25-35CAFDK(X)S50CFVK(X)S25-50BAFLK(X)S25-50BAStep Cooling Heating Cooling Heating Cooling Heating Cooling HeatingLLLLLSLLMLMMHHHH (Powerful) H+70 H+50 H+50 H+50 H+90 H+90 H+50 H+50(R6035) (R6036) (R6035) (R6036)(R6037)(R6036)(R6037)(R6036)+1.5°C+0.5°C+2°C+1°CMMLL(R4594)Difference between roomand set temperatureThermostatsettingtemperature DC motor: Rotation speed controlAC motor: Phase controlfan speed
