Heating and Air Conditioning: Description and Operation
REFRIGERANT FLOWThe refrigerant flow is in the standard pattern. Refrigerant flows through the compressor, condenser, Liquid tank evaporator, and back to the compressor.
The refrigerant evaporation through the evaporator coil is controlled by an externally equalized expansion valve, located inside the evaporator case.
REFRIGERANT SYSTEM PROTECTION
Triple-pressure switch
The triple or dual-pressure switch is located on the liquid tank. If the system pressure rises or falls out of specifications, the switch opens to interrupt compressor clutch operation. The triple-pressure switch closes to turn on the cooling fan to reduce system pressure (USA model only).
Pressure relief valve
The refrigerant system is protected by a pressure relief valve. The valve is located on the end of the flexible high pressure hose near the compressor. When refrigerant system pressure increases abnormally [over 3,629 kPa (37 Kg/sqcm, 526 psi)], the relief valve's port opens. The valve then releases refrigerant into the atmosphere.