Samsung Electronics 206Piping DiagramElectronic Expansion Valve – Main (Main EEV)ƒ PurposeControl the EEV to adjust the refrigerant flow according to the amount of heat exchanged by the outdoor heat exchanger in heatingmode.ƒ ConceptThe 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.ƒ Control specifications in detailIn case of cooling operation, leave Main EEV fully open. In case of heating operation, control the Main EEV by assuming the outdoorunit 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 theevaporated pressure during outdoor period.EEV control period : every 20sControlled by capacityDSH normalHeat recovery operation?Target SH ControlTarget SH = Water temperatrue - 3ఁTarget SH controlTarget SH = (Low pressure-10)*7+5EEV control repeatDSH protection controlYesYesNoNoNo7-3 Functions (cont.)7-3-2-1 Actuator (cont.)7-3-2 Control (cont.)
