Samsung AM072BXV Series Service Manual page 236

Piping Diagram
7-3 Functions (cont.)
7-3-2 Control (cont.)
7-3-2-1 Actuator (cont.)
Solenoid Valve – Main EEV
▪ Purpose
In main cooling mode, enable the Main EEV to control the amount of refrigerant flowing in the cooling indoor units.
▪ Concept
- In main cooling mode, the valve is closed to prevent refrigerant from flowing using Check Valve.
- EEV Bypass and enable the Main EEV to control the amount of refrigerant flowing into the cooling indoor units.
- If the valve is opened, most refrigerant is bypassed via the valve which flows into the cooling indoor units.
As a result, there is insufficient refrigerant in active indoor units that are under heating mode.
- HR Only
▪ Control specifications in detail
In main cooling mode, the valve is Off (closed).
Solenoid Valve – Main Cooling
▪ Purpose
In main cooling mode, enable operation of heating indoor units.
▪ Concept
- In main cooling mode, the valve is opened to send the high pressure to heating indoor units and enable heating.
- HR Only
▪ Control specifications in detail
In main cooling mode, the valve is On (opened)
Solenoid Valve - Accumulator Oil Return (ARV)
▪ Purpose
Return oil stagnating in the accumulator.
▪ Concept
- During compressor operation, the valve is opened to return oil stagnating in the accumulator.
- The valve is closed to protect the compressor in start-up mode or in a section where there is concern about the potential for liquid
compression due to low DSH.
▪ Control specifications in detail
- Condition(s) required to close (Off) the valve : [ A or B or C ]
A. The system has stopped
B. DSH is higher than 10 K during start-up
C. The valve is closed for 2 minutes if DSH is higher than 10 K in air conditioning mode.
- Condition(s) required to open (On) the valve : None of the conditions required to close the valve are satisfied.
Compressor Coil Heater (CCH)
▪ Purpose
Prevent compressor failure due to liquid compression or poor lubrication during compressor start-up.
▪ Concept
If the internal temperature of an inactive compressor is abnormally low, the internal temperature is increased through the CCH to evap-
orate the liquid refrigerant that has flowed into the compressor. This will prevent liquid compression and poor lubrication.
▪ Control specifications in detail
- It is turned On if A or B is satisfied.
A. The highest temperature of the compressor has remained below 50℃ for 2 min.
B. The CCH has been Off for longer than 6 hours.
- Condition(s) required to turn Off the CCH: [ A or B ]
A. The highest temperature of the compressor has remained above 55℃ for 30 min.
B. The CCH has been On for longer than 6 hours.
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