Fan Mode; Auto Mode; Cold Draft Prevention - Daikin FTXB50BV1B Service Manual

Function & Control
2.2.2 Heating Mode:
When Ts > Tr - 1.0°C
• Compressor, Indoor Fan and Outdoor Fan ON.
Ts Tr - 1.5°C
When ≤
• Compressor and Outdoor Fan OFF. Indoor Fan remained ON.
• Indoor Fan off if indoor coil ≤ 20°C.
Tr = Room Temperature
Ts = Set Temperature
When heating load is too small, and the room temperature still rising above compressor cut off point,
compressor will stop.
Compressor Capacity
Lowest Frequency

2.3 Fan Mode

• Compressor and Outdoor Fan OFF. Indoor Fan remained ON.
• Only High, Medium and Low fan speeds are allowed.
• When changing cool mode to fan mode, the compressor will stop and OD fan stops based on fan OFF
control.
• Compressor only ON if the minimum stop time is > 3 minutes and the user change back to cool mode.
• Fan speed will maintain same as during fan mode.

2.4 Auto Mode

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.
For heat pump only
Mode switching point:
• From Heating to Cooling
Tr ≥ Ts + 2.5
• From Cooling to Heating
Tr ≤ Ts – 2.5
During initial operation
• Cooling operation: Tr > Ts
• Heating operation: Tr < Ts

2.5 Cold Draft Prevention

During each thermal cut in cycle, the indoor fan speed will modulate according to the indoor coil temperature.
• If indoor coil temperature > 36
• If indoor coil temperature < 15
• If indoor coil temperature 15
°
C, indoor fan will run at user set fan speed.
°
C, indoor fan will stop.
° °
C<X < 36 C, the indoor fan will run at low speed
Tr - T
Compressor will stop
Time
14