–24–
(3) Fan control
Controls the fan speed based on the piping temperature (TH1) to perform cooling at low outdoor temperatures and heating
at high outdoor temperatures.
1) Control at cooling
a) When the compressor stops, the fan stops (fan output = 0 %).
b) When the power is turned on, or when the compressor is restated after it has been stopped for 30 minutes or
longer, the piping temperature ( TH1) determines the fan output.
When TH
≤
25˚C
Fan output = 100 %
When TH < 25˚C
Fan output = 60 %
c) When the compressor is restarted within 30 minutes after it has been stopped, the fan step before the compres-
sor was stopped is selected. However, when the fan output was under 30% when the fan was stopped, 30 % is
selected.
d) When the mode was changed from heating to cooling, the fan step conforms to item 2.
e) Two minutes after the fan is started, the fan step (number of units) is controlled every 30 seconds based on the
piping temperature (TH1).
f)
When TH1 reaches 50˚C or higher, or when the control high pressure switch (63H2) tripped, the fan output
becomes 100 %.
g) Fan output while the compressor is operating is within the 20 % to 100 % range.
• FAN step
The following expression determines the next fan step count nj+1:
nj + 1 = nj +
∆
nj
nj: Current fan step,
∆
nj: Displacement step amount
nj control
• If nj + 1
≥
100 % nj + 1 = 100 %
• If nj + 1
≥
20 % nj + 1 = 20 %
• If TH1
≥
50
°
C or 63H2 is “OFF”
nj + 1 = 100 %
FAN
∆
nj
Outputs are all %.
* In the night mode, the maximum value of nj is 80%. (When TH1 < 50˚C)
Target condensation
temperature 31
°
C
Condensation temperature TH1
20
≤
nj < 50
50
≤
nj 100
Current
output
t > 49
°
C
5
10
t = 49
t > 46
3
4
~
~
~
~
~
~
~
~
~
t = 46
t > 43
2
3
t = 43
t > 40
2
2
t = 40
t > 36
2
2
t = 36
t > 33
2
2
t = 33
t > 29
0
0
t = 29
t > 26
–2
–2
t = 26
t > 23
–2
–2
t = 23
t > 20
–3
–4
t
≤
20 ˚C
–5
–10
