Panasonic U-8MF2E8 - Page 25

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3WAY SYSTEM
Control Functions
1
4. Output of PCB
4-8-3. Expansion Valve for Heat Exchanger Control
The configuration of the heat exchangers is different depending on the capacity of the outdoor unit.
When operating in all cooling or all heating mode, the heat exchangers of which the compressors are driving in the
outdoor units are used.
However, when operating in cooling mode with low ambient temperature, the number of pieces for using the heat
exchanger is changed according to the operating condition of indoor units and the status of outdoor units.
When operating in mixed cooling/heating mode, the condition and the number of pieces for using the heat exchanger
are changed according to the operating condition of indoor units and the status of outdoor units.
The heat exchanger is selected in turn from the outdoor unit heat exchanger 1 as the shortest operating time of the
inverter compressor.
SH control is controlled so that the difference of temperature between the liquid tube temperature and gas tube
temperature should be set within the range as shown below.
Operation of electronic control valves during normal unit operation
Heat exchanger
[condenser] of
outdoor unit
Normal Condenser Maximum flow control
Condenser
Evaporator
Stop
Stop
Evaporator
Stop
Condenser
Stop
Stop
Heat exchanger capacity control
SH control
Refrigerant shut-off
Refrigerant shut-off
SH control
Refrigerant shut-off
Heat exchanger capacity control
Refrigerant shut-off
Refrigerant shut-off
Status of
heat exchanger
System stopped
Low ambient
temperature
Other outdoor
units operating
Heat exchanger
[evaporator] of
outdoor unit
All
cooling
mode
All
heating
mode
Mixed
cooling/
heating
operation
MOV1
480
120〜480
0
20〜480
0
0
65〜480
0
20〜480
0
MOV2 Remarks
480
105〜480
0
20〜480
0
0
50〜480
0
20〜480
0
Outdoor unit Capacity
-1 ~ 5°C
Target value of SH control
2 ~ 5°C
All heating mode
Mixed cooling/heating operation (Heat exchanger [evaporator] of outdoor unit)
SM830226-003WAYECO-iSYSTEM.in1717SM830226-003WAYECO-iSYSTEM.in1717 2013/02/1311:52:252013/02/1311:52:25