Haier 1U71S2SG1FA Service Manual

Also see for 1U71S2SG1FA: Installation manual Service manual Installation manual

Contents

2192.3.12 Oil return operation control2.3.12. Oil return operation controlUnitary:A Entering conditionWhen the compressor running frequency is lower than 58Hz continuously in all and outdoorunit Tcm is lower than 50 degree for 5 hours, the system will enter oil return operation. In thecourse of mode changeover, manual unit stop or protective unit stop, the time will beaccumulative. After compressor restarts up, the time will counted continuously. In countingtime for 5 hour, if the compressor running frequency is over 80Hz for 10 minutes continuously,the time will be cleared. Also after the heating defrosting , the time will be cleared.B ProcedureCooling mode: refer to “the oil return procedure in cooling mode”Heating mode: refer to “the oil return procedure in heating mode”C The protection treatment in oil return operation:In the course of cooling oil return, because of all kinds of protection or abnormal unit stop,after the unit restart, the time will not be cleared, the system need another oil return operation.In the refrigerant flow course in oil return of cooling mode or after oil return, and within 5minutes after the refrigerant being eliminated is over, the anti-freeze protection and lowpressure protection are invalid, other protection is valid.In the course of heating oil return ,because of all kinds of protection or abnormal unit stop, thesystem need not another oil return operation after the unit stop for 3 minutes and enter inheating mode directly. In the course of changing to cooling oil return, the anti-freezeprotection and low pressure protection are invalid, other protection is valid.Oil return procedure in cooling mode:Send oil return signal oil return beginning oil return overref.eliminated 30s80 Hz（E）40HZ（E）Inverter compressor auto FQY300pulse （E）outdoor unit PMV auto open angle auto open angle120pulse（E）Outdoor fan motor auto operation auto（TC or ambient control） auto operationrunning indoor motor auto operation auto（set fan speed） auto operationstop indoor motor stop stop stop4-way valve OFF OFF OFF60SUnitary:A: Entering conditionWhen the compressor running frequency is lower than 58Hz continuously in all and outdoor unit Tcm is lowerthan 50 degree for 5 hours, the system will enter oil return operation. In the course of mode changeover, manualunit stop or protective unit stop, the time will be accumulative. After compressor restarts up, the time will countedcontinuously. In counting time for 5 hour, if the compressor running frequency is over 80Hz for 10 minutescontinuously, the time will be cleared. Also after the heating defrosting , the time will be cleared.B: ProcedureCooling mode: refer to "the oil return procedure in cooling mode"Heating mode: refer to "the oil return procedure in heatingmode" mode"C: The protection treatment in oil return operation:In the course of cooling oil return, because of all kinds of protection or abnormal unit stop, after the unit restart, thetime will not be cleared, the system need another oil return operation. In the refrigerant flow course in oil return ofcooling mode or after oil return, and within 5 minutes after the refrigerant being eliminated is over, the anti-freezeprotection and low pressure protection are invalid, other protection is valid.In the course of heating oil return, because of all kinds of protection or abnormal unit stop, the system need notanother oil return operation after the unit stop for 3 minutes and enter in heating mode directly. In the course ofchanging to cooling oil return, the anti-freeze protection and low pressure protection are invalid, other protection isvalid.Oil return procedure in cooling mode: