Refrigerant Circuit ESIE09-0814 Refrigerant Circuit1.2 Indoor UnitEKHBRD 011/014/016 AA(V1/Y1)No. inrefrigerantsystemdiagramSymbol Name Major FunctionA M1C Inverter compressor onR-134a Inverter compressor is operated on frequencies between 40 Hz and 210 Hz by usingthe inverter. Max. of 30 steps.B Y1R Four way valve Used to switch the operation mode between heating and defrost. Not activated duringheating (opposite concerning outdoor unit).C B1PL Low pressure sensor Used to detect low pressure.D B1PH High pressure sensor Used to detect high pressure.E S1PH High pressure switch In order to prevent the increase of high pressure when a malfunction occurs, thisswitch is activated at high pressure of 3.8 MPa or more to stop the compressoroperation.F K2S 2-way valve Used during defrost operation.G K1E Electronic expansion valve Used to regulate the refrigerant flow of R-410A.H K2E Electronic expansion valve Used to regulate the refrigerant flow of R-134a.I E1HC Crankcase heater Used to prevent migration (when the unit is OFF) and condensation of refrigerant inthe crankcase of compressor.J M1P DC inverter pump Used to regulate water flow to achieve a constant ΔT.K Q2L Thermistor protector waterpiping Used to protect the water system against high temperatures.L K1S 3 way valve (option for watertank) Used to switch over between space heating and domestic hot water.1 R3T Liquid thermistor R-410A Subcool calculation.2 R6T Discharge thermistor Used to detect discharge pipe temperature, make the temperature protection control ofcompressor, and others.3 R7T Liquid thermistor R-134a Subcool calculation.4 R4T Returning water thermistor Used to control and protect the water system.5 R5T Leaving water thermistor Used to control and protect the water system.
