Master And Slave Unit's Eev Control - LG MULTI V M ARNU07GTU 4 Series Svc Manual

Function
1.3 EEV control
(1) Main EEV control
Main EEV operates with fuzzy control rules to keep the degree of super Heat(Superheat) (about 3°C)at
the evaporator outlet stable during heating mode
The degree of Superheat = Tsuction - Tevaporation
Tsuction : temperature at suction pipe sensor(°C)
Tevaporation : evaporation temperature equivalent to low pressure(°C)
(2) Subcooling EEV control(about 15°C)
Subcooling EEV works with fuzzy rules to keep the degree of Subcool at the outlet of subcooler during
cooling mode
The degree of Subcool = Tcondensation - Tliquid
Tliquid : temperature at outlet of subcooler(°C)
Tcondensation : condensation temperature equivalent to high pressure(°C)
(3) Avoiding excessive high discharge temperature : when main EEV opens some given opening and dis-
charge temperature is above 85°C in heating operation, subcooling EEV may control the "subcooling
out temperature-evaporating temperature" to be some given difference.
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