Thermostat Operation; Fan Control During Heating Thermostat Off - Mitsubishi Heavy Industries FDT Series Technical Manual

(8)

Thermostat operation

(a) Cooling
Thermostat is operated with the room temperature control.
1)
Thermostat is turned ON or OFF relative to the set room temperature as shown below.
2)
Thermostat OFF
Thermostat is turned ON when the room temperature is in the range of -1 < Set temperature < +1 at the start of cooling
3)
operation (including from heating to cooling).
(b) Heating
Thermostat is operated with the room temperature control.
1)
Thermostat is turned ON or OFF relative to the set room temperature as shown below.
2)
Heater ON
-1
Thermostat is turned ON when the room temperature is in the range of -1 < Set point < +1 at the start of cooling opera-
3)
tion (including from cooling to heating).
(c) Fan control during heating thermostat OFF
Following fan controls during the heating thermostat OFF can be selected with the indoor function setting of the wired
1)
remote controller.
Low
When the "Low fan speed (Factory default)" is selected, the following taps are used for the indoor fans.
2)
When the "Set fan speed" is selected, it is operated with the set fan speed also in the thermostat OFF condition.
3)
If the "Intermittence" is selected, following controls are performed:
4)
a) If the thermostat is turned OFF during the heating operation, the indoor unit moves to the hot control and turns
OFF the indoor fan if the heat exchanger thermistors (both ThI-R1 and R2) detect 25°C or lower.
meantime the louver is controlled at level.
c) After operating at ULo for 2 minutes, the indoor fan moves to the state of a) above.
d) If the thermostat is turned ON, it moves to the hot start control.
e) When the heating thermostat is turned OFF, the remote controller displays the temperature detected at the fan stop
and revises the temperature later when the indoor fan changes from ULo to stop.
The remote controller uses the operation data display function to display temperatures and updates values of
temperature even when the indoor fan is turned OFF.
f) When the defrosting starts while the heating thermostat is turned OFF or the thermostat is turned OFF during
defrosting, the indoor fan is turned OFF. (Hot keep or hot start control takes priority.) However, the suction
temperature is updated at every 7-minute.
g) When the heating thermostat is turned ON or the operation is changed to another mode (including stop), this
control is stopped immediately, and the operating condition is restored.
When the "Fan OFF" is selected, the fan on the indoor unit of which the thermostat has been turned OFF, is turned OFF.
5)
Thermostat ON
-1 +1
Set room temperature
Thermostat ON
-1
+1
3C
Set room temperature
(Factory default), Set fan speed,
Temperature drop
Temperature rise
Thermostat OFF
+1
Heater OFF
Intermittence,
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Temperature rise
Temperature drop
Fan OFF