8. Outdoor Fan Control
W-2WAY ECO-i SYSTEM Control Functions
8-1. Fan mode
These outdoor units utilize a DC fan motor that can be controlled in a maximum of 16 steps (16 modes). However, fan modes 15 and 16 can only be used if high
* For information concerning EEPROM settings, refer to the field application functions.
8-2. Outdoor Fan Min. Fan Mode and Max. Fan Mode
| Min. fan mode | Max. fan mode | 1 |
Cooling operation | Outdoor air temp. > 59°F: 1 | 14 | |
Outdoor air temp. < 59°F: 0 |
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Heating operation | 1 | 14 |
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*Even if the fan mode is 0 during cooling operation, the fan mode may change to 1 at regular intervals for tem- perature protection of the inverter hybrid IC.
8-3. 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 horsepower changes dramatically, say for about 2 hp, the initial mode may be recalculated and may be again fixed for 30 seconds.
8-4. Operation after Fixed Initial Fan Mode
After the fixed initial fan mode, the fan mode is increased or decreased according to the operating conditions.
(1)When all indoor units are operating in cooling mode
(A)Fan mode is increased when the high pressure satulation temperature sensed by the pressure sensor is high, and is decreased when the pressure sensor temperature is low.
* The fan mode is always increased when the high pressure satulation temperature sensed by the pressure sensor is 113°F or higher.
(B)The fan mode may be decreased when symptoms of insufficient refrigerant gas are detected at an indoor unit.
(2)When all indoor units are operating in heating mode
(A)If the condensation temperature is low, the fan mode is increased at regular intervals.
(B)If the condensation temperature is high, the fan mode is decreased in order to prevent excessive loads.
(C)The fan mode may be increased when the outdoor liquid temperature drops to 44°F or below.
8-5. Snow Removal Control
(1)When the outdoor air temperature is 50°F or below, the fan operates for 30 seconds every 2 hours in fan mode 8, even when the outdoor unit is stopped or the heat exchanger is not in use. This control is intended to prevent snow from accumulating on stopped fans. (Because the outdoor air temperature cannot be accurately detected when the unit is stopped, a higher outdoor air temperature is used for the control condition, in order to ensure correct operation.)
(2)If the fan mode becomes 0 during cooling operation, the fan mode is changed to 1.
* This control is predictive control. Use a snowfall sensor as necessary according to the installation conditions.
8-6. When the Compressor Magnet Switch Seizing Alarm Occurs
Because there is the possibility that the high pressure has increased, the fan operates in Max. fan mode.
8-7. Other
This unit includes settings for high
For information about these settings, refer to the field application functions.
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