Pump Down Procedure - LG LA090HYV3 Installation Manual

FINAL INSTALLATION PROCEDURES

Pump Down Procedure

Pump Down Procedure
Use Pump Down Procedure when the refrigerant piping system needs to be serviced. Pumping
down collects all the refrigerant in the system and pipes it to the outdoor unit without losing any
charge. Always adhere to and be familiar with local codes regarding the handling of refrigerant.
The system must operate in Cooling Only mode to proceed with the pump down procedure. If
needed, refer to the previous sections for proper steps to place the unit into Cooling Only mode.
1. Turn off the power to the system.
2. Remove the cap from the vapor (gas) service valve. Connect the gauge manifold hose to the gas
(vapor) suction Schrader port on the gas service valve.
3. Open the gas (vapor) suction Schrader port on the gas service valve halfway, and purge the air
in the manifold hose.
4. Turn the power on. Operate the system in Cooling Only Mode for at least ten (10) minutes; verify
that the compressor is operating properly.
5. Fully close the liquid piping service valve to the outdoor unit by rotating the valve clockwise with
an Allen wrench.
6. Observe the pressure gauge reading. When it changes to 14.2 to 7.1 psig, fully close the gas (vapor) service valve, and then immediately
turn the unit off. Pump down procedure is complete and all refrigerant will be collected into the outdoor unit.
Do not operate the unit in Pump Down for an extended period. It will damage the compressor.
7. Disconnect the gauge manifold hose to the gas (vapor) suction Schrader port on the gas service valve.
8. If necessary for service, disconnect the pipe to the outdoor unit. To protect the outdoor unit from air, vapor, and debris, block the outdoor
valve by installing a flare nut through the pipe after brazing the end of the disconnected pipe.
9. Re-attach the cap to the vapor (gas) service valve, using a torque wrench to firmly tighten.
•
• After pump down, power must be turned OFF before the pipe is removed. If the system is operated without the pipe connected, air inside
Always perform Pump Down procedure in the Cooling Only mode.
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Figure 128: Connecting the Manifold
Hose.
Gauge Manifold
Figure 129: Closing the Outdoor Unit
Liquid Piping Service Valve.
Micron
Gauge