Mitsubishi Heavy Industries V Multi FDC71VNX Technical Manual page 100

1.10.3 Operation control function by the indoor control
(1) Auto operation
(a) If "Auto" mode is selected by the remote control, 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 (ATM corner of bank).
Heating operation
Room temperature (detected with Thi-A) [deg]
Notes (1) Temperature range of switching cooling/heating mode can be changed by RC-EX3 from ±1.0 - ±4.0.
(2) Room temperature control during auto cooling/auto heating is performed
according to the room temperature setting temperature. (DIFF: ±1 deg)
(3) 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.
(b) The following automatic controls are performed other than (a) above.
(i) Cooling or heating operation mode is judged according to the conditions of the "Judgment based on Setting temperature +
Cooling select temperature and Indoor return air temperature" and the "Judgment based on Outdoor temperature".
1)  I n "Setting temperature - Cooling select temperature < Indoor return air temperature" and "Outdoor temperature/Cooling <
Outdoor return air temperature" ⇒ Operation mode: Cooling
2)  " Setting temperature + Heating select temperature > Indoor return air temperature" and "Outdoor temperature/
Heating > Outdoor air temperature" ⇒ Operation mode: Heating
3) The outdoor air temperature of the above judgment conditions is sampled at every 10 minutes.
4) In the range where the above cooling and heating zones are overlapped ⇒ Forced thermostat OFF
Cooling operation
-3 +3
Cooling select temperature
30
28
26
Forced thermostat OFF
24
22
20
18
16
Heating
14
12
12 14 16 18
Indoor return air temperature (℃)
Heating OK
Indoor heat exchanger temperature (°C)
Heating select temperature
Cooling
Forced
thermostat OFF
Forced thermostat
OFF
20 22 24 26 28
Setting temperature
99
- -
'19 • PAC-T-327
Heating operation stopped (cooling)
56 59
Outdoor temperature/Heating
Outdoor temperature/Cooling
30