Carrier 42NQ009N Service Manual

Contents

FILE NO. SVM-1003618 --(3) The indoor heat exchanger restricts revolvingspeed of the fan motor to prevent a cold draft. Theupper limit of the revolving speed is shown inFig. 7-3-10 and Table 7-3-2.7-3-5. Automatic operation([MODE] button on the remote control is setto the automatic operation.)(1) One of 3 operations (Cooling, Fan only or Heating)is selected according to difference between thepreset temperature and the room temperature atwhich the automatic operation has started, asshown in Fig. 7-3-11. The Fan only operationcontinues until the room temperature reaches alevel at which another mode is selected.(2) Temporary AutoWhen the RESET button on the indoor unitis pushed, the preset temperature is fixed at 24°Cand the indoor unit is controlled as shown inFig. 7-3-11* No limitation while fan speed MANUAL mode is in stability.* A: When Tsc ≥ 24, A is 24, and when Tsc < 24, A is TscTsc: Set valueHLine-approximateH and SUL with Tc.SULStop46 46Tc3445 45 3333 33 2132 32 20*A+0 *A+0 *A+0*A-8 *A-8 *A-8Fan speed MANUAL in startingFan speed AUTO in stabilityFan speed AUTO in startingFig. 7-3-10 Cold draft preventing controlTable 7-3-2Fan *5 *6speed Starting period Stabilized periodAUTO • Up until 12 minutespassed after startingthe unit• From 12 to 25 minutespassed after startingthe unit and roomtemperature is 3°Clower than presettemperatureManual • Room temperature(L – H) < Preset temperature–4°C• From 12 to 25 minutespassed after startingthe unit and roomtemperature isbetween presettemperature and 3°Clower than presettemperature• 25 minutes or morepassed after startingthe unit• Room temperaturePreset temperature–3.5°C(Room temp.) − (Preset temp.)0°CCooling operationFan only operation-1Fig. 7-3-11Heating operation