Panasonic U-4LE1E5, Service Manual, Page: 18 / 133

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1
Mini VRF SYSTEM
Control Functions
(1)
(a)
*
(b)
(2)
(a)
(b)
(c)
•
After the fixed initial fan mode, the fan mode is increased or decreased according to the operating conditions.
Indoor cooling operation
The fan mode is increased when the pressure sensor temperature is high, and is decreased when the
pressure sensor temperature is low.
The fan mode is always increased when the pressure sensor temperature is 50°C or higher.
The fan mode may be decreased when symptoms of insufficient gas are detected at an indoor unit.
Indoor heating operation
If the condensation temperature is low, the fan mode is increased at regular intervals.
If the condensation temperature is high, the fan mode is decreased in order to prevent excessive load.
The fan mode may be increased when the outdoor liquid temperature drops to 7°C or below.
7-4. When Compressor Magnet Switch Seizing Alarm Occurs
Quiet mode operation
For the setting procedure, refer to the separate instructions. When Quiet mode is activated, the maximum fan
mode is reduced compared to maximum fan mode during normal operation.
Because the high pressure may increase, operation occurs at the maximum fan mode.
Outdoor unit
4 hp
1 13
14
5, 6 hp
14
14
Min. fan mode Max. fan mode
Cooling operation
Heating operation
Outdoor air temp. > 36°C: 3
Outdoor air temp. 36°C: 1
*
These outdoor units utilize a DC fan motor that can be controlled using a maximum of 15 increments (15 fan
modes).
7-1. Outdoor Fan (Min.Fan Mode and Max.Fan Mode)
7-2. Fixed Initial Fan Mode
For the first 30 seconds after operation starts, the mode is fixed at the initial mode that was calculated based on
the relationship between the outdoor air temperature and the outdoor unit horsepower.
If the outdoor unit horsepower changes dramatically, the initial mode may be recalculated and may be again fixed
for 30 seconds.
7-3. Operation after initial fan mode is fixed
However, during cooling operation if the outdoor air temperature is 30°C or higher, the maximum fan mode
is 14.
Heating operation
Cooling operation
Outdoor unit
4 hp
10
11
5, 6 hp
11
12 (*14)
Max. fan mode
7. Outdoor Fan Control
SM830195-01̲Mini VRF SYS.indb 12 SM830195-01̲Mini VRF SYS.indb 12 2011/12/20 16:31:04 2011/12/20 16:31:04