2WAY SYSTEM
Control Functions - Outdoor unit
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5. Outdoor Unit Fan Control
5. Outdoor Unit Fan Control
2WAY VRF SYSTEM
Control Functions
(1) Number of Fan Motor
These outdoor units utilize a DC fan motor that can be controlled in a maximum of 13 steps (13 modes) in ordinary
mode.
The control range is expanded to a maximum of 15 steps (15 modes) if high static-pressure mode has been set.
The fan rotating numbers will be changed according to the fan mode.
(2) Fan Mode
3-1. Maximum rotation number of fan
3-2. Minimum rotation number of fan
Maximum rotation number of fan is limited regardless of the fan mode as shown below.
Minimum rotation number in fan mode is limited by the secondary current value and ambient temperature as
shown in the table below.
A mode that has higher number of revolutions than that written in the table below becomes the minimum fan
mode.
Temperature of Outdoor (TO)
(3) Minimum Fan Mode and Maximam Fan Mode
NOTE
If the upper limit rotation number is changed, it cannot be changed for 3 minutes.
The frost formation detect line should be used the same type as described uner the section “9. Defrost
Control”.
A minimum temperature detected from among each gas and liquid refrigerant temperatures is recognized
as the minimum temperature of the outdoor unit heat exchanger(s).
This is called a detect temperature.
TO < 0°C
TO ≥ 40°C
SC > 15.0A
Secondary
Current
(SC)
0°C ≤ TO
< 10°C
10.0A < SC ≤ 15.0A
5.0A < SC ≤ 10.0A
SC ≤ 5.0A
450rpm
360rpm
100rpm
0rpm
500rpm
380rpm
120rpm
0rpm
550rpm
420rpm
140rpm
0rpm
600rpm
460rpm
280rpm
100rpm
700rpm
550rpm
300rpm
120rpm
800rpm
560rpm
320rpm
140rpm
10°C ≤ TO
< 20°C
20°C ≤ TO
< 30°C
30°C ≤ TO
< 40°C
Type of outdoor unit
Number of fan motor
8
〜
16HP
18
･
20HP
1
2
Type of outdoor unit
8
〜
16HP
8
〜
16HP
18HP
20HP
Cooling mode
Heating mode
750rpm
800rpm
800rpm
750rpm
840rpm : the outdoor air temperature
≤
10°C
800rpm : the outdoor air temperature > 10°C
2WAY VRF SYSTEM
Control Functions
5. Outdoor Unit Fan Control
(4) Fixed Initial Fan Mode
For the first 30 seconds after operation starts, the mode is fixed at the initial mode which was calculated from
the relationship between the outdoor air temperature and the outdoor unit horsepower.
If the outdoor unit compressor capacity changes dramatically, the initial mode may be recalculated and may
be again fixed for 30 seconds.
(5) Operation after Fixed Initial Fan Mode
After the fixed initial fan mode, the fan mode is increased or decreased according to the operating conditions.
5-1. Cooling operation
* The fan mode is always increased when the detected high pressure sensor temperature is 46°C or higher.
Fan mode is increased when the detected high pressure saturated temperature is high, and is decreased when
the high pressure saturated temperature is low.
The fan mode may be decreased when the system detects refrigerant shortage at an indoor unit.
During cooling operation, if the fan mode becomes “0” and this condition maintains for 3 minutes, the fan mode
is changed to “1”.
5-2. When all indoor units are operating in heating mode
If the pressure sensor temperature is low, the fan mode is increased at regular intervals.
If the pressure sensor temperature is high, the fan mode is decreased in order to prevent excessive loads.
The fan mode may be increased when the liquid temperature of outdoor unit heat exchanger drops to 1 degrees
Celsius or below.
Temperature of Outdoor (TO)
TO < 0°C
TO ≥ 40°C
SC > 19.0A
Secondary
Current
(SC)
0°C ≤ TO
< 10°C
18.0A < SC ≤ 19.0A
17.0A < SC ≤ 18.0A
12.0A < SC ≤ 17.0A
480rpm
480rpm
480rpm
320rpm
480rpm
480rpm
480rpm
320rpm
500rpm
500rpm
500rpm
340rpm
530rpm
530rpm
530rpm
360rpm
610rpm
610rpm
570rpm
420rpm
750rpm
640rpm
570rpm
570rpm
9.0A < SC ≤ 12.0A
160rpm
160rpm
160rpm
180rpm
220rpm
310rpm
7.0A < SC ≤ 9.0A
100rpm
100rpm
100rpm
100rpm
100rpm
150rpm
SC ≤ 7.0A
0rpm
0rpm
0rpm
0rpm
100rpm
100rpm
10°C ≤ TO
< 20°C
20°C ≤ TO
< 30°C
30°C ≤ TO
< 40°C
18
･
20HP
SM830253-00_欧州2way7_SM-TRSM.indb 16
16/08/26 19:23:16
