Automatic Operation - Daikin FTX20K(2)V1B Service Manual

SiBE041525F
1.6

Automatic Operation

Outline
Automatic Cooling / Heating Function
When the automatic operation is selected with the remote controller, the microcomputer
automatically determines the operation mode as cooling or heating according to the room
temperature and the set temperature at start-up.
The unit automatically switches the operation mode to maintain the room temperature at the set
temperature.
Detail
1. The set temperature (Ts) determines the target temperature (Tt).
2. The target temperature (Tt) is calculated as;
3. Thermostat ON/OFF point and operation mode switching point are as follows.
4. During initial operation
Ex: When the target temperature is 25°C
Functions and Control
Ts: set temperature (set by remote controller)
Tt: target temperature (determined by microcomputer)
Tr: room thermistor temperature (detected by room temperature thermistor)
C: correction value
(Ts = 18 ~ 30°C).
Tt = Ts + C
where C is the correction value
C = 0°C
Tr means the room thermistor temperature.
(1) Heating → Cooling switching point:
Tr ≥ Tt + 3.0°C
(2) Cooling → Heating switching point:
Tr < Tt – 3.0°C
(3) Thermostat ON/OFF point is the same as the ON/OFF point of cooling or heating
operation.
Tr ≥ Ts : Cooling operation
Tr < Ts : Heating operation
Target temperature – 2.0˚C
= Thermostat OFF
Target temperature – 3.0˚C
Cooling → 23°C: Thermostat OFF → 22°C: Switch to heating
Heating → 27°C: Thermostat OFF → 28°C: Switch to cooling
.
Cooling Operation
Target temperature + 3.0˚C
Target temperature + 2.0˚C
= Thermostat OFF
Heating Operation
Main Functions
(R22027)
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