Fan Speed Control For Indoor Units - Daikin CTXS09GVJU Service Manual

SiUS12-814
1.3

Fan Speed Control for Indoor Units

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 the troubleshooting for fan motor on page 118.
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, the fan operates H tap + 50 - 90 rpm.
2. Fan stops during defrost operation.
Automatic
On heating mode, the indoor fan speed will be regulated according to the indoor heat exchanger
Airflow Control temperature and the difference between the room temperature and the required set point.
for Heating
Automatic The following drawing explains the principle of fan speed control for cooling:
Airflow Control
for Cooling
Function and Control
Step
= Within this range the airflow rate is automatically controlled when the FAN setting button
is set to automatic.
fan speed
+Δ2.7˚F
+Δ0.9˚F
Thermostat
setting
temperature
Cooling Heating
750 - 1000 rpm
(During powerful operation :
(R2818) (R2818)
M
+Δ3.6˚F
ML
+Δ1.8˚F
L
Phase control
Main Functions
Dry mode
1050 rpm)
Difference between room
and set temperature
(R4146)
27