Operation Control Function By The Indoor Controller; Room Temperature Control; Heating Operation; Cooling Operation - Mitsubishi Heavy Industries FDCA Series Technical Manual

(2) Operation control function by the indoor controller

(a) Room temperature control (Differential of thermostat)

Heating operation

Temperature difference between thermostat set temp.
and return air temp. (Detected by Th
(b) Automatic operation
If the Auto mode is selected on the remote control device, the selection of cooling or heating can be made automatically
depending on the room temperature (and the temperature of indoor heat exchanger). (When the switching between the
cooling and the heating is made within 3 minutes, the compressor will not operate for 3 minutes.) This will make much easier
the switching of cooling/heating at the change of season and can be adapted to the unmanned operation at bank cash dis-
penser.
Heating operation
Room temp. (detected at
Ready for
heating
56
Indoor heat exchanger temperature (˚C)
(c) Control parts operation during cooling and heating
Function
Control part
Compressor
4-way valve
Outdoor fan
Indoor fan
Louver motor
Condensate motor
Note (1) :ON
× :OFF
/ × :According to control other than temperature control.
OFF
-1 +1
Set temp.by thermostat
-A)
I

Cooling operation

Setting room temp.
Th -A
) [deg]
I
Suspended heating operation
59
Cooling Fan
Thermostat Thermostat
–
ON OFF
× ×
× × ×
× ×
× (5min. ON) × (5min. ON)
Cooling operation
OFF (52C)
-1
Temperature difference between thermostat set
temp. and return air temp. (Detected by Th
Notes (1) During the automatic switching of cooling/heating the room
temperature is controlled based on the setting of room temperature.
Notes (2) If the temperature of indoor heat exchanger rises beyond 59˚C during
the heating operation, it is switched automatically to the cooling
operation. For an hour after this switching, the heating operation is
suspended regardless of the temperature as shown at left.
Heating
Thermostat Thermostat
Defrost
ON OFF
×
×
/ ×
(5min. ON)
68
- -
ON
+1
Set temp.by thermostat
-A)
I
Dry
HOT START
×
×
/ ×
–
×
/ ×