SiENBE05-722_A
1.4
Fan Speed Control for Indoor Units
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 72.
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>
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, the fan rotates at H tap + 50 rpm.
2. The fan stops during defrost operation.
Function and Control
Step
= The airflow rate is automatically controlled within this range when the FAN setting
button is set to automatic.
fan speed
+1.5°C
+1.5°C
+0.5°C
+0.5°C
Cooling
Heating
(R11578)
(R11577)
M
Difference between the room thermistor
+2°C
ML
temperature and the target temperature
+1°C
L
Main Functions
(R12390)
25