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31
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'12 • SRK-T-126
9.3 Operation control function by the indoor controller
(a) Auto operation
If “Auto” mode is selected by the remote controller, the heating and the cooling are automatically switched according to the
difference between outdoor air temperature and setting temperature and the difference between setting temperature and return
air temperature. (When the switching of cooling mode
↔
heating mode takes place within 3 minutes, the compressor does
not operate for 3 minutes by the control of 3-minute timer.) This will facilitate the cooling/heating switching operation in
intermediate seasons and the adaptation to unmanned operation at stores, etc.
Note (1) Room temperature control during auto cooling/auto heating is performed according to the room temperature setting temperature. (DIFF: ±1 deg)
(2) If the indoor heat exchanger temperature rises to 59°C or higher during
heating operation, it is switched automatically to cooling operation. In
addition, for 1 hour after this switching, the heating operation is not
performed, regardless of the temperature shown at right.
Room temperature setting temperature
+3
-3
Cooling operation
Heating operation
Room temperature (detected with Th
I
-A) [deg]
59
56
Heating operation stopped (cooling)
Heating OK
Indoor heat exchanger temperature (°C)
(b) Operations of functional items during cooling/heating
Cooling
Heating
Dehumidify
Fan
Operation
Functional item
Thermostat
ON
Thermostat
ON
Thermostat
OFF
Thermostat
OFF
Hot start
(Defrost)
Compressor
4-way valve
Outdoor unit fan
Indoor unit fan
Louver motor
Drain pump
(3)
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: Turned ON/OFF by the control other than the room temperature control.
(2) ON during the drain motor delay control.
(3) Drain pump ON setting may be selected with the indoor unit function setting of the wired remote controller.
(c) Dehumidifying operation
1) When the humidity sensor is not provided
Return air temperature thermistor [Th
I
-A (by the remote controller when the remote controller thermistor is enabled)]
controls the indoor temperature environment simultaneously.
a) Operation is started in the cooling mode. When the difference between the return air temperature and the setting
temperature is 2°C or less, the indoor unit fan tap is brought down by one tap. That tap is retained for 3 minutes
after changing the indoor unit fan tap.
b) If the return air temperature exceeds the setting temperature by 3°C during defrosting operation, the indoor unit fan
tap is raised. That tap is retained for 3 minutes after changing the indoor unit fan tap.
c) If the thermostat OFF is established during the above control, the indoor unit fan tap at the thermostat ON is retained
so far as the thermostat is turned OFF.
d) After stopping the cooling operation, the indoor unit continues to run at Lo for 15 seconds.
2) When the humidity thermistor is provided [Optional]
a) Operation starts in the cooling mode, and the target relative temperature is determined based on the setting
temperature. If the humidity detected by the humidity thermistor becomes lower than the target relative temperature,
the indoor unit fan tap is retained.
b) Anything other than a) above is same as the item 1) above.
