Refrigeration Cycle

REFRIGERANT FLOW
The refrigerant flows in the standard pattern. It flows from compressor through condenser, liquid tank, evaporator and back to compressor.
The refrigerant evaporation through the evaporator coil is controlled by an externally equalized expansion valve, located inside the evaporator case.

FREEZE PROTECTION
The compressor cycles on and off to maintain the evaporator temperature within a specified range. When the evaporator coil temperature falls below a specified point, the thermo control amplifier interrupts the compressor operation. When the evaporator coil temperature rises above the specification, the thermo control amplifier allows compressor operation.


REFRIGERANT SYSTEM PROTECTION

Triple-pressure switch
The refrigerant system is protected against excessively high or low pressure. The protection is effected by the triple-pressure switch located on the liquid tank. If the pressure rises or falls out of specifications, the switch opens to interrupt the compressor operation. Also, triple-pressure switch operates the cooling fan motor.

Pressure relief valve
The refrigerant system is also protected by a pressure relief valve. The valve is located on the bottom of the compressor. When refrigerant pressure in the system increases abnormally [over 3,727 kPa (38 kg/Sq.cm, 540 psi)], the relief valve's release port opens automatically. The valve then releases refrigerant into the atmosphere.