Fan Speed Control For Indoor Unit - Daikin FTXN09KEVJU Service Manual

Main Functions
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. 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 82.
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.
09/12 class
*In automatic fan speed operation, upper limit is at M tap in 30 minutes from the operation start.
15/18/24 class
<Heating>
On heating mode, the fan speed is regulated according to the indoor heat exchanger temperature
and the difference between the room thermistor temperature and the target temperature.
Note: 1. During POWERFUL operation, fan rotates at H tap + 80 ~ 90 rpm.
2. Fan stops during defrost operation.
24
Step
09/12 class
= The airflow rate is automatically controlled within this range when the FAN setting button
is set to automatic.
Fan speed
+2.5˚C (+4.5˚F)
+1.5˚C (+2.7˚F)
+0.5˚C (+0.9˚F)
Fan speed
+1.5˚C (+2.7˚F)
+0.5˚C (+0.9˚F)
Cooling
15/18/24 class
(R6833)
(R11681)
Room thermistor temperature – target temperature
MH*
+3˚C (+5.4˚F)
M
+2˚C (+3.6˚F)
ML
+1˚C (+1.8˚F)
L
Room thermistor temperature – target temperature
M
+2˚C (+3.6˚F)
ML
+1˚C (+1.8˚F)
L
SiUS041111
Heating
(R6834)
(R14720)
(R14659)
Function and Control