Carrier 40VM Series Service Manual

Also see for 40VM Series: Installation and operating instructions Installation and operating instructions Installation and operating instructions Installation and operating instructions

Contents

7Function and ControlELECTRONIC EXPANSION VALVE OPERATION — Electronic expansion valves of the indoor unit regulate the refrigerantflow to control superheat during cooling operation and subcooling during heating operation.Table 6 —List of 500P EEV Opening in Cooling ModeTable 7 —List of 2000P EEV Opening in Cooling Mode500P EEV Operation DriverWhen the indoor unit receives the following signal:• Signal to turn OFF• Indoor unit error signal• Indoor unit turns to fan mode• Indoor unit turns to thermo-OFF• Indoor unit shut down due to low temperature protection on the evaporatorThe EEV’s control uses the following logic:• If the outdoor unit shuts down without cooling capacity requirement:The EEVs keep previous opening for three minutes.Then EEVs conduct 300P opening (EEV whose opening is not equal to zero will close to 0P first, then open to 300P).• If the cooling capacity requirement of the outdoor unit is not equal to 0, the EEVs keep the previous opening for 25 secondsafter the indoor unit turns off, then close to -16P to reset the opening and standby.When the indoor unit receives the turn ON signal, the EEVs control uses the following logic:CAPACITY INDEX INITIAL OPENING MINIMUM OPENING MAXIMUM OPENING7~18 120 54 48024 120 54 48030 120 54 48036 120 54 480Larger than 48 120 54 480CAPACITY INITIAL OPENING MINIMUM OPENING MAXIMUM OPENINGLess than 12 300 104 200015~18 200 104 200024 300 104 200030 400 104 2000Larger than 36 400 104 2000