Below, information on how to give the correct refrigerant fluid load.
Equipment required for system equipped with liquid sight glass
- Low pressure manometer (-30 to 120 psi) connected to the suction line,
- High pressure manometer (0 to 500 psi) connected to the discharge line,
- Bottle with coolant.
Procedures
- After a good vacuum in the system (200 microns) and leak testing, connect the bottle of coolant to the suction line or system liquid tank through the service valve or process tube; charge the circuit completely with refrigerant
in the gaseous or liquid state, depending on the refrigerant to be used,
- Start the compressor by observing the liquid display and adding load slowly until the display is completely full and without bubbles,
- The bottle of coolant can cool and even freeze the bottom. To prevent this from happening, the coolant bottle can be placed in a container with water or air stream (front of the compressor).
Caution: Never heat the bottle with a torch as it may cause explosions.
System not equipped with liquid sight glass
- The same equipment and procedure mentioned above is used, with addition of thermometer, which will be connected to the liquid line,
- As the refrigerant charge approaches the ideal, the discharge pressure read on the pressure gauge should be converted to a temperature in ° C and subtract from the measured temperature in the liquid line. This difference should be between 2 ° C and 8 ° C (subcooling); if these values are below, add load, if the values are above, remove load.
