Fan Speed Control For Indoor Unit - Daikin FTXZ25NV1B Service Manual

SiMT041311E
1.4

Fan Speed Control for Indoor Unit

Outline Phase control and fan speed control contains 9 steps: LLL, LL, SL, L, ML, M, MH, H, and HH.
The airflow rate can be automatically controlled depending on the difference between the room
thermistor temperature and the target temperature.
Automatic Fan In automatic fan speed operation, the step SL is not available.
Speed Control
LLL
LL
L
ML
M
MH
H
HH (POWERFUL)
<Cooling>
The following drawing explains the principle of fan speed control for cooling.
<Heating>
In heating operation, the fan speed is regulated according to the indoor heat exchanger
temperature and the difference between the room thermistor temperature and the target
temperature.
Indoor Unit Quiet Forced dropping of the fan tap decreases the airflow rate and reduces airflow noise. (Noise is
reduced by about 3 dB as compared to that in L tap.)
Operation
Note
Function and Control
Step
= The airflow rate is automatically controlled within this range when the FAN button is
set to automatic.
Room thermistor temperature – target temperature
Airflow rate can not be set.
Since the performance is lowered as compared to that in normal operation (70% under rated
conditions), the room may not be cooled or heated when this operation is used for a long
time.
Indoor unit quiet operation is kept in memory even when the power supply is turned OFF.
The indication remains on the display of the wireless remote controller and the indoor unit
quiet operation works when the power is turned ON again.
Cooling Heating
(R6834)
(R11681)
+3°C
+2°C
+1°C
0°C
Main Functions
Fan speed
MH
M
ML
L
(R19668)
18