Samsung AM072BXV Series Service Manual page 235

Piping Diagram
7-3 Functions (cont.)
7-3-2 Control (cont.)
7-3-2-1 Actuator (cont.)
Solenoid Valve – EVI, Solenoid Valve - EVI Bypass
▪ Purpose
Switch between EVI Bypass Mode, EVI On Mode, and EVI Off Mode, depending on the EVI EEV status.
▪ Concept
- Solenoid valve – EVI : When Vapor/Flash Injection is in use, the valve is closed to let refrigerant flow into the compressor.
- Solenoid valve - EVI Bypass : If a compressor has stopped, the valve is closed to prevent the refrigerant that has passed through
▪ Control specifications in detail
Control valves according to the EVI Mode, as shown below.
Electronic Expansion Valve
EVI Mode
EVI Bypass mode
EVI On mode
EVI Off mode
Solenoid Valve - Hot Gas Bypass
▪ Purpose
Protect the system when high pressure is abnormally high or low pressure is abnormally low.
▪ Concept
If either pressure is abnormal, the valve is opened to bypass the high-pressure gas to the low pressure pipe.
This will change the pressure.
▪ Control specifications in detail
ON if high pressure is above 39.5kgf/cm2,g / OFF if below 38.5kgf/cm2,g
ON if cooling low pressure is below 3.2kgf/cm2,g / OFF if above 4.2kgf/cm2,g (at minimum frequency, OFF if above 6.0kgf/cm2,g)
ON if cooling low pressure is below 0.9kgf/cm2,g / OFF if above 1.7kgf/cm2,g
Solenoid Valve - Hot Gas Bypass 2
▪ Purpose
Prevent refrigerant from stagnating in the high pressure gas pipe in cooling-only mode.
▪ Concept
- In cooling-only mode, the valve is opened to switch the high pressure gas pipe to the low pressure gas pipe.
- If the valve is closed, refrigerant stagnates in the high pressure gas pipe causing a lack of refrigerant.
- HR Only
▪ Control specifications in detail
If using the Heat Recovery device, the valve is opened (ON) after cooling-only mode has been on for more than 20 minutes or when
cooling oil return mode is active.
Samsung Electronics
the EVIEEV from flowing into the compressor.
Solenoid valve
- EVI
Open
Open
Close
Solenoid valve
- EVI - EVI Bypass
Open Open
Open Close
Open Open
* Condition
Normal Operation
- All comp. in unit 70hz ↑
- Ambient Temp. < 36℃ (cool)
< 10℃ (heat)
- Control by unit
- Safety start
- Defrost
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