Mitsubishi Heavy Industries FDT28KXE6A Service Manual page 15

(5) Outdoor fan control (Master unit/slave unit)
(a) DC fan motor control
The outdoor fan is controlled from 0th speed to 4th speed, and set the standard speed according to the model and operation
mode.
Under normal condition, 1st speed and 4th speed is standard, and under each condition the stepless fan control between 1st
speed and 4th speed is performed.
(b) Outdoor fan speed and fan motor rotation speed
Fan tap
0th speed
1st speed
2nd speed
3rd speed
4th speed
Fan tap
0th speed
1st speed
2nd speed
3rd speed
4th speed
(c) At the unit startup, outdoor fan is operated at 4th speed.
(d) DC fan motor startup control
①
When the outdoor fan starts after stopping, the startup fan control is performed by checking the fan speed.
②
If the rotating direction of the stopping fan, either FMo1 or FMo2, is reverse and its speed is 700min
both fans cannot be started.
③
If the rotating direction of the stopping fans, both FMo1 and FMo2, are reverse but its speed is less than 700min
3 seconds continuously, the fan can be started.
④
During the period of 5 seconds after 52C1 is turned ON, the outdoor DC fan is prohibited to start.
FDC335, 400
Cooling Heating
FM 1 FM 2 FM 1
O O O
0 0 0
0 160 0
0 400 0
160 160 160
960 960 960
FDC504∼680
Cooling Heating
FM 1 FM 2 FM 1
O O O
0 0 0
0 160 0
0 400 0
160 160 160
1140 1140 1140
FDC450
Cooling
FM 2 FM 1 FM 2
O O O
0 0 0
160 0 160
400 0 400
160 160 160
960 1080 1080
Unit: min
Remarks
FM 2
O
0 Stop
160 1-unit operation min. speed
400 1-unit operation max. speed
160 2-unit operation min. speed
1140 2-unit operation max. speed
13
- -
Heating Remarks
FM 1 FM 2
O O
0 0 Stop
0 160 1-unit operation min. speed
0 400 1-unit operation max. speed
160 160 2-unit operation min. speed
1080 1080 2-unit operation max. speed
-1
Unit: min
-1
-1
or higher, the
-1
for