Samsung AM080FXWANR Service Manual page 207

Piping Diagram
7-3 Functions (cont.)
7-3-2 Control (cont.)
7-3-2-1 Actuator (cont.)
Electronic Expansion Valve – Main (Main EEV)
Purpose
Control the EEV to adjust the refrigerant flow according to the amount of heat exchanged by the outdoor heat exchanger in heating
mode.
Concept
The valve is fully opened in cooling mode.
The EEV step is regulated through PD control to enable operation according to the target SH (superheat) degree in heating mode.
Control specifications in detail
In case of cooling operation, leave Main EEV fully open. In case of heating operation, control the Main EEV by assuming the outdoor
unit SH. In case that DSH is over the setting value, control it via SH control.
Make sure to perform a balanced control so that the required vapor cannot be concentrated to a certain outdoor unit considering the
evaporated pressure during outdoor period.
Samsung Electronics
EEV control period : every 20s
Controlled by capacity
DSH normal
Yes
Heat recovery operation?
Yes
Target SH Control
Target SH = Water temperatrue - 3
No
EEV control repeat
No
DSH protection control
No
Target SH control
Target SH = (Low pressure-10)*7+5
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