TCL TAC-07CHSA/XA71 Service Manual page 8

Air Conditioner Service Manual
b. Indoor fan motor automatic airflow speed control, it works as shown in Figure 1:
Hi
Mid
Lo
RT－ST 1°C 2°C 4°C
Figure 1 Cooling automatic airflow
When the temperature changing leads the fan speed variation, the switch can only be made orderly,
and in every grade of air flow speed should run 1 minute at least.
3. Dry mode
While select to this mode, the air conditioner operates for 3 minutes according to cooling mode firstly
(ST set at 7°C), and then takes the detected backflow air temperature minus 2°C as a new set
temperature (the lowest temperature: 5°C) and runs according to cooling mode, indoor fan operates at
low-speed, at this moment the setting operation of fan speed invalid but Swing adjustable.
4. Heating mode
On the Heating mode, the room temperature (RT) is compensated (CRT), a fter that, the room
temperature displayed on the LED is CRT=RT-3°C.
1) The control of the compressor
a. When ST－CRT≥1°C，the compressor is running.
b. When ST－CRT＜-1°C，the compressor stops.
c. When -1°C≤ST－CRT＜1°C, the compressor keeps its original state
2) Outdoor fan motor and the compressor run simultaneously (except for defrosting)
3) The control of indoor fan motor:
a. Indoor fan motor can operate by automatic, low, middle, or high airflow speed circularly.
b. Indoor fan motor automatic airflow speed control, it works as shown in Figure 2:
Hi
Mid
Lo
ST－CRT 1°C 2°C 4°C
Figure 2 Heat automatic airflow
When the temperature changing leads the fan speed variation, the switch can only be made orderly,
and every grade of air flow speed should run 1 minute at least.
4) Vane motor control: run as set state.
5) 4-way valve control:
a. Under heating mode, the four-way valve maintains well-connected status (including the
compressor stops on set condition, except for the defrosting process)
b. When the mode switches into the heating mode or A/C start-up, four-way valves will open 5
Seconds before the compressor starts; while the mode exits from the heating mode or A/C turn off,
the four-way valve will close 2min later after shut-down the compressor.
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