Trane TVR Pro CO Series Service Manual page 20

Key components:
1. Oil separator:
Separates oil from gas refrigerant pumped out of the compressor and quickly returns it to the compressor. Separation
efficiency is up to 99%.
2. Accumulator:
Stores liquid refrigerant and oil to protect compressor from liquid hammering.
3. Electronic expansion valve (EXV):
Controls refrigerant flow and reduces refrigerant pressure.
4. Solenoid valve SV2:
Protects the compressor. If compressor discharge temperature rises above 100
amount of liquid refrigerant to cool the compressor. SV2 closes again once the discharge temperature has fallen
below 90 C.
o
5. Solenoid valve SV4:
Returns oil to the compressor. Opens once the compressor has run for 200 seconds and closes 600 seconds later and
then opens for 3 minutes every 20 minutes.
6. Solenoid valve SV7:
Allows refrigerant to return directly to the compressor. Opens when indoor air temperature is close to the set
temperature to avoid frequent compressor on/off. Opens when superheat degree is insufficient to avoid liquid
hammer to compressor.
7. Low pressure switches:
Regulate system pressure. When system pressure falls below the lower limit, the low pressure switches turn off,
stopping the compressor. After 10 minutes, the compressor restarts.
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o C, SV2 opens and sprays a small