System Description

REFRIGERATION SYSTEM


System Description


REFRIGERANT CYCLE

Refrigerant Flow
The refrigerant flows from the compressor, through the condenser with a liquid tank, through the evaporator, and then back to the compressor. The refrigerant evaporation in the evaporator is controlled by an externally equalized expansion valve, located at dash panels.

Freeze Protection
To prevent the evaporator from freezing up, the evaporator air temperature is monitored, and the voltage signal to the A/C auto amp. turns the A/C relay OFF and stops the compressor.

REFRIGERANT SYSTEM PROTECTION

Refrigerant Pressure Sensor
The refrigerant system is protected against excessively high or low-pressures by the refrigerant pressure sensor, located on the liquid tank. The refrigerant pressure sensor detects the pressure inside the refrigerant line and sends the voltage signal to the ECM if the system pressure rises above, or falls below the specifications.
ECM turns the A/C relay OFF and stops the compressor when pressure on the high-pressure side detected by the refrigerant pressure sensor is over approximately 3,119 kPa (31.8 kg/cm2, 452 psi) or below approximately
118 kPa (1.2 kg/cm2, 17 psi).

Pressure Relief Valve
The refrigerant system is also protected by a pressure relief valve, located in the rear head of the compressor.
The release port on the pressure relief valve automatically opens and releases refrigerant into the atmosphere when the pressure of the refrigerant in the system increases to an unusual level [more than 3,600 kPa (36.7 kg/cm2, 522 psi)].