BGH BV-V28W/DHN1 Manual page 20

Figure 2-4.3: 48/56 model Piping diagram
Accumulator
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. Gas-liquid separator:
Stores liquid refrigerant and oil to protect compressor from liquid hammering.
3. Electronic expansion valve (EXV):
Controls refrigerant flow and reduces refrigerant pressure.
4. Four-way valve(ST1):
Controls refrigerant flow direction. Closed in cooling mode and open in heating mode. When closed, the heat exchanger
functions as a condenser; when open, the heat exchanger functions as an evaporator.
5. High and low pressure switches:
Regulate system pressure. When system pressure rises above the upper limit or falls below the lower limit, the high or
low pressure switches turn off, stopping the compressor. After 5 minutes, the compressor restarts.
19