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
of liquid refrigerant to cool the compressor. SV2 closes again once the discharge temperature has fallen below 90
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.
o C, SV2 opens and sprays a small amount
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o C.