BP Unit Control SiEBE18-52676 Function6.2 BP Unit Electronic Expansion Valve ControlPurpose of theFunctionThis function provides instructions regarding the absolute flow rate, relative flow rate and fullyclosing from the outdoor unit to the BP unit in order to ensure outdoor unit compressor safetyand optimum refrigerating cycle of the system.With the transmission a permit/prohibit flag for each distribution control in the BP unit, thedistribution control startup timing is controlled by the outdoor unit.6.2.1 Electronic Expansion Valve Initial Opening SettingOutline This function improves stability of the system to set initial opening of electronic expansion valveat starting operation.When the EV opening command from outdoor unit is lifted, the following opening setting isperformed.During CoolingOperationTarget EV opening = 2.5 × (DA - 14) + P5 - KEVOPC × (DOA - DA) plsDA: room temperature, DOA: outdoor air temperatureDuring HeatingOperationTarget EV opening = 350 pls6.2.2 Electronic Expansion Valve Flow Rate RestrictionThis function prevents the deviation from the electronic expansion valve specification range byrestricting the electronic expansion valve flow rates of the operating and non-operating roomunits during compressor operation. It also prevents the generation of abnormal noise such asrefrigerant flowing sound by restricting the circulation of refrigerant according to the operatingconditions (unit ON/OFF) of room units.Outline Restriction of electronic expansion valve opening degrees of operating room units;... Restriction of maximum and minimum flow rates based on constantRestriction of electronic expansion valve opening degrees of non-heating room units;... Restriction of minimum flow rate based on constant... Maximum flow rate determined based on flow rates of operating room unitsP5: KEVOPC:Indoor unit capacity P5 KEVOPC2.0 to 3.5 kW class 140 DOA≤DA 05.0 kW class 156 DA<DOA 2.56.0, 7.1 kW class 170
