Daikin SkyAir Super Inverter 70 D Series, Service Manual

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SiE25-110 Function of Main Components and Thermistors
Function and Operation 67
(A) Compressor
Inverter drive unit varies compressor operating frequency to control capacity and other
factors.
(B) Check Valve Bridge Circuit
Regulates refrigerant flow to maintain high pressure in liquid receiver at all times.
(C) Electronic Expansion Valve
Provides control to maintain optimum operating condition for high efficiency.
(D) Solenoid Valve Y1S
Equalizes pressure in non-operating condition, and controls oil supply during defrosting
operation.
(E) 4 way Valve
Changes operation of cooling / heating.
∗
Coil energized : heating
Coil not energized : cooling
(F) Solenoid Valve Y2S
Used for increasing capacity by subcooling liquid refrigerant passing through the double tube
type heat exchanger.
R1T (Outdoor Air Thermistor)
Used for startup condition control and defrost control.
R2T (Heat Exchanger Thermistor)
Used for protection control during overload cooling operation and defrost control.
R3T (Discharge Thermistor)
Used for discharge temperature protection during compression operation.
R4T (Suction Pipe Thermistor)
Used for suction super heat control by electronic expansion valve.
R5T (Power Module Thermistor)
Used for inverter protection.