Heating Operation; Intermittent Fan Mode - Fujitsu Airstage V-II Service Manual

Intermittent fan mode

Fan step Fan mode
6 intermittent 6
5 intermittent 5
4 intermittent 4
3 intermittent 3
2 intermittent 2
1 intermittent 1
Normal fan step
300 rpm
0 rpm
When switched from normal fan step to intermittent fan step, always start from 300rpm/7sec.
When there was a change during intermittent step 1-6, switching is performed at the time the current speed
duration time reaches time-up.

2-3-2 Heating Operation

Fan step
AJ A72LALH AJ A90LALH AJ A108LALH AJ A126LALH AJ A144LALH
16
15
14
13
12
11
10
9
8
7
Switching conditions of step
The initial speed of the first boot outdoor unit is detected by outdoor air temperature sensor value (TAOUT).
Outside air temperature
sensor detected value
TAOUT 10°C
10°C TAOUT 15°C
15°C TAOUT 20°C
20°C TAOUT
Thereafter, the high-pressure is monitoring at a set time interval and the fan speed is changed by the following conditions.
Other outdoor units are normally operated at fan step 16.
(Condition which lowers the fan speed)
High-pressure 3.30MPa and heat sink temperature
(Condition which raises the fan speed)
High-pressure saturation
Fan speed 0 rpm
duration time T ( sec )
6
12
19
26
33
40
Intermitten fan step
7 sec 7 sec
[ T ] sec
Fan speed (rpm)
880 880
860 860
830 830
700 700
600 600
500 500
420 420
360 360
320 320
300 300
Fan step
16
12
7
7
3.20MPa or heat sink temperature
Fan speed 300 rpm
duration time ( sec )
7
7 sec
[ T ] sec
880 920
860 870
830 820
700 700
600 600
500 500
420 420
360 360
320 320
300 300
75°C
80°C
02-07
Time
920
870
820
700
600
500
420
360
320
300