Fan Speed Control For Indoor Units - Daikin FTXS09DVJU Service Manual

Main Functions
1.3 Fan Speed Control
Control Mode The airflow rate can be automatically controlled depending on the difference between the set
temperature and the room temperature. This is done through phase control and Hall IC control.
For more information about Hall IC, refer to trouble shooting for fan motor on page 126.
Phase Steps Phase control and fan speed control contains 9 steps: LLL, LL, SL, L, ML, M, MH, H and HH.
In automatic operation, the step "SL" is not available.
LLL (Heating thermostat OFF)
LL (Cooling thermostat OFF)
L
ML
M
MH
H
HH (Powerful)
Note: 1. During powerful operation, fan operate H tap + 50 - 90 rpm.
2. Fan stops during defrost operation.
Automatic Air On heating mode, the indoor fan speed will be regulated according to the indoor heat exchanger
temperature and the difference between the room temperature and the required set point.
Flow Control for
Heating
Automatic Air The following drawing explains the principle of fan speed control for cooling:
Flow Control for
Cooling
22
for Indoor Units
Step
= Within this range the airflow rate is automatically controlled when the FAN setting button
is set to automatic.
fan speed
+∆2.7˚F
+∆0.9˚F
Thermostat
setting
temperature
Cooling Heating
(R4085) (R4085)
M
+∆3.6˚F
ML
+∆1.8˚F
L
Phase control
SiUS04-702
Difference between room
and set temperature
(R4146)
Function and Control