R-134a Final Charging Procedure for Partially Charged Units

Note Final charge the R-23 system first when both the R-134a and R-23 systems require charging.

  1. Connect the gauge manifold to the suction line and discharge line service ports. Be sure to purge the air from the lines (see “Gauge Manifold Set Attachment and Purging” in the Refrigeration Maintenance chapter of this manual).

  2. Back seat and crack the discharge service valve.

  3. Connect a refrigerant tank to the gauge manifold service line.

      Caution
    • Service Procedure
    • Be sure to add the correct refrigerant to the system.

  4. Set the R-134a refrigerant tank for liquid charging. Open the refrigerant tank hand valve.

  5. Start and operate the unit in the COOL mode.

      Caution
    • Equipment Damage
    • Do NOT operate the unit on cooling unless: R-23 refrigeration system contains a FULL charge of refrigerant. R-134a refrigeration system contains a partial charge of refrigerant.

  6. Read the suction pressure and slowly open the gauge manifold low pressure hand valve to permit suction pressure to increase approximately 170 kPa, 1.7 bar, 25 psig. This will meter liquid refrigerant slowly into the low side.

  7. Add R-134a refrigerant until the receiver tank balls float at the top of the sight glass.

  8. Close the hand valve on the refrigerant tank.

  9. Operate the unit on COOL for 10 minutes and recheck refrigerant charge.

  10. Remove the gauge manifold set.

  11. Cap all service ports and valve stems.

Note

    Caution
  • Service Procedure
  • Be sure to add the correct refrigerant to the system.
Parent topic: Charging System with Refrigerant