Outdoor Fan Speed Control During Heating; Snow Protection Fan Control; Outdoor Air Temperature (˚C) - Mitsubishi Heavy Industries FDCA Series Technical Manual

2) During heating operation, the fan speed is controlled in accordance with the outdoor heat ex-
changer temperature (detected by Tho-R) and the outside air temperature (detected by Tho-A).
Tho-A
Tho-R
Zone D
Zone E
Zone E
Outdoor heat exchanger temperature (˚C)
Notes (1) The temperature at whichever outdoor heat exchanger temperature thermistor (Tho-R1 or R2) has the lowest reading is detected.
3) The fan speed is controlled in accordance with the outdoor heat exchanger temperature (de-
tected by Tho-R) and the outside air temperature (detected by Tho-A) during cooling or dehu-
midifying.
Tho-A
Tho-R
Zone C
Zone D
Zone E
Zone B
Outside air temperature (˚C)
Notes (1) The temperature at whichever outdoor heat exchanger temperature thermistor (Tho-R1 or R2) has the highest reading is detected.

4) Outdoor fan speed control during heating

a) If the fan starts when the outside air temperature (detected by Tho-A) is 12ºC or higher, the outdoor fan motor
runs at speed A for 4 minutes, then after 4 minutes control switches to the outdoor fan speed control in item 2).
Model
801H
1001H
b) Even if the outside air temperature (detected by Tho-A) drops below 12ºC during operation with the outdoor
fan motor OFF, the outdoor fan motor continues to run at 2th speed for 4 minutes.
(c) Snow protection fan control
If SW5-2 (SW3-2) on the outdoor unit PCB is turned ON, a full stop results. Then in the abnormal stop mode and with the
thermostat OFF unit's outdoor fan outdoor temperature at 3ºC or lower, the fan is run for 10 seconds at 6th speed once every 10
minutes [Hi tap (4th speed)] .
Note (1) Items is ( ) show in the case of models FDCA801, 1001.
Zone A Zone B
1th speed 4th speed
1th speed 4th speed
Zone D
-3 0
Zone A Zone B
4th speed 4th speed
4th speed
2th speed
2th speed
1th speed
Zone A
22 25
Control speed
Speed A
1th speed
0th speed
ON
Outdoor air temperature (˚C)
Zone C
4th speed
4th speed
Zone C
3
Outside air temperature (˚C)
Zone E
26
Outdoor heat exchanger temperature (˚C)
OFF
3 5
77
- -
Zone A
Zone B
12 15
5
Zone C
Zone D
46 55
44