Operations Of Functional Items During Cooling/Heating - Mitsubishi Electric FDT125VNVF Technical Manual

② Regardless of the setting temperature, the cooling or heating operation mode is judged according to the "Judgment based on Room
temperature/Cooling or Heating and Outdoor temperature/Cooling or Heating".
・ I n case of "Room temperature/Cooling < Indoor return air temperature" and "Outdoor temperature/Cooling < Outdoor air tempera-
ture" ⇒ Operation mode: Cooling
・ I n case of "Room temperature/Heating > Indoor return air temperature" and "Outdoor temperature /Heating > Outdoor air tem-
perature" ⇒ Operation mode: Heating
・ The outdoor air temperature of the above judgment conditions is sampled at every 10 minutes.
・ In the range where the above cooling and heating zones are overlapped ⇒ Forced thermostat OFF
(2)

Operations of functional items during cooling/heating

Operation
Thermostat
Functional item
Compressor
4-way valve
Outdoor unit fan
Indoor unit fan
(3)
Drain pump
Note (1) �: Operation �: Stop �/�: 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.
(3) Dehumidifying operation
Return air temperature thermistor [Th
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 dehumidifying 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.
Room temperature/Cooling
30
28
26
Forced thermostat OFF
24
22
Forced thermostat
OFF
20
18
16
Heating
14
12
12 14 16 18 20
Indoor return air temperature (℃)
Cooling
Fan
Thermostat
ON OFF
� � �
� � �
� � �
� � �
� � (2) �
-A (by the remote controller when the remote controller thermistor is enabled)]
I
Room temperature/Heating
Cooling
Forced thermostat
OFF
22 24 26 28 30
Heating
Thermostat Thermostat
ON OFF
� �
� �
� �
�/� �/�
(2) �/� (2)
300
- -
'12 • PAC-T-174
Outdoor temperature/Heating
Outdoor temperature/Cooling
Dehumidify
Hot start
(Defrost)
�
�/�
�(�)
�
�(�)
�/�
�/�
�/�
Thermostat ON: �
�
(2)
Thermostat OFF: