Service Manual

SiUS041638E Main Functions
Functions and Control 16
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
Speed Control
In automatic fan speed operation, the step SL is not available.
= The airflow rate is automatically controlled within this range when FAN button is set to
automatic
.
Cooling
The following drawing explains the principle of fan speed control for cooling.
*The upper limit is M tap in 30 minutes from the operation start.
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.
Note: The fan stops during defrost control.
COMFORT
AIRFLOW
Operation

The fan speed is controlled automatically within the following steps.
Cooling
L tap ~ MH tap (same as automatic)
Heating
LL tap ~ M tap
Step Cooling Heating
LLL
LL
L
ML
M
MH
H
HH (POWERFUL)
(R11681)
(R6834)
(R21654)
Fan speed
+2.5°C (+4.5°F)
+1.5°C (+2.7°F)
+0.5°C (+0.9°F)
MH*
M
ML
L
+3°C (+5.4°F)
+2°C (+3.6°F)
+1°C (+1.8°F)
Room thermistor temperature – target temperature