-
42
-
6) Outdoor unit fan control by power transistor cooling fan temperature
If all the following conditions are established 3 minutes after the compressor starts, the following control is imple-
mented.
a) Cooling, Dehumidifying
●
Outdoor air temperature Tho-A >
= 33
°
C
●
Actual compressor speed >
= 60 rps
●
Power transistor cooling fan temperature >
= 80
°
C
b) Heating
●
Outdoor air temperature Tho-A >
= 16
°
C
●
Actual compressor speed >
= 70 rps
●
Power transistor cooling fan temperature >
= 80
°
C
c) Control contents
i)
The outdoor unit fan tap speed is increased by 1 speed.
ii) When sampling is done once every 60 seconds and the power transistor cooling fan temperature (Tho-P)
value is as follows.
1
If the power transistor cooling fan temperature (Tho-P) is >
= 80
°
C, the outdoor unit fan tap’s speed
increases by 1 speed.
2
If 80
°
C > the power transistor cooling fan temperature (Tho-P) >
= 75
°
C, the current outdoor unit fan tap
speed is maintained.
3
If the power transistor cooling fan temperature (Tho-P) is <
= 75
°
C, the outdoor unit fan tap speed is
lowered by 1 speed.
d) End conditions
When the conditions in item
3
above and the outdoor unit fan tap speed determined in item (i) are sensed 2
times in succession.
(e)
Outdoor unit fan control during cooling when the outdoor air temperature is low
( i ) When cooling or defrosting, if the outdoor air temperature (Tho-A) is in Zone B and when the outdoor unit’s fan has run
for 20 seconds since starting and is running at 1 speed, the outdoor unit’s fan speed is controlled in accordance with the
outdoor heat exchanger temperature (Tho-R1).
(ii) If the rotational speed drops, the speed is held constant for 20 seconds, then if the conditions in (i) exist after 20 seconds,
the speed is lowered further. The same is true in the case that the speed is increased. The speed is held constant for 20
seconds, then if the conditions in (i) exist 20 seconds later, the speed is increased further.
●
Speed lower limit: 130 rpm
●
Speed upper limit: 500 rpm
5
10
Outdoor unit fan speed
+10min
-1
Outdoor unit fan speed
-10min
-1
Retention
20
Outdoor heat exchanger temperature (˚C)
30
A
Zone
B
Zone
Outdoor air temperature (˚C)
