Refrigerant Circuit Pressures And Temperatures: Notes

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CAUTION:

When performing work on refrigerant circuit, observe all generally applicable safety precautions and pressure container regulations.

The pressures and temperatures in the refrigerant circuit depend on the current operating conditions (such as engine RPM, coolant fan level 1, 2 or 3, engine temperature, A/C compressor on or off) as well as on the effects of outside influences (such as outside temperature, humidity, desired cooling output).

In vehicles with A/C Compressor Regulator Valve -N280-, the pressure is modified on the low pressure side by the -N280-.

For this reason, values indicated in the following table are valid only as reference points. They are attained at an engine speed of 1500 to 2000 RPM and an ambient temperature of 20 °C after approximately 20 minutes.

The connections for the pressure gauge set intended for the pressure measurement are indicated on the vehicle specific refrigerant circuit. Refer to [For engine(s) CTUA, CEUC, CRDB, CGXB, CPNB] System Overview - Refrigerant Circuit or (vehicle-specific repair information).

At 20 °C with the engine not running, the pressure in the refrigerant circuit is 4.7 bar. Refer to REFRIGERANT R134A VAPOR PRESSURE TABLE (vapor pressure table).

NOTE:

Pressure is measured in different units: 1 MPa (mega Pascal) corresponds to 10 bar positive pressure or 145 psi. 1 bar absolute pressure corresponds to 0 bar positive pressure and thus to the ambient pressure (atmospheric pressure).