Air Purging - LG ART COOL LA090HSV4 Installation Manual

Air Purging Best Practices
Air purging is done to the piping system after all piping has been connected between the
indoor and outdoor unit. This step is necessary to be sure that air refrigerant can flow
through the system without danger of leakage or pressure issues. Air and moisture that
is left in the piping can lead to undesirable results and can cause damage to the working
unit. It is important to go through a complete air purging cycle to be sure that the lines are
cleared out. Note that you may have to repeat this process should any air or moisture be
found to remain in the piping. After air purging and evacuating the lines, be sure to take a
leak test for all piping and tubing.
Insufficient or incorrectly done air purging may lead to the following:
• Pressure in the system can rise.
• Operating current can rise.
• Cooling or heating efficiency falls.
• Moisture in the refrigerant circuit may freeze and block capillary tubing.
• Water can lead to corrosion of parts in the system.
Air Purging with a Vacuum Pump - Preparation Steps
1. Verify that each set of pipes (liquid and gas) are properly connected between the indoor
and outdoor unit.
• Verify that all wiring for a test run has been completed.
2. Remove service valve caps from the gas and liquid valves at the outdoor unit (Figures 55
and 56).
• Both the liquid and gas side service valves at the outdoor unit should be kept closed at
this step.
3. Set up the purging, hose connections by referring to Figure 57.
4. Do a Leak Test, by proceeding to Soap Water Method - Leak Testing section on next page.
• Successful leak testing must be performed before Evacuation can begin.
5. Go to Evacuation section, on page 37 to complete the purging process.
Figure 57: Evacuation Setup
Air Purging/ Evacuation Setup
Indoor Unit
Outdoor Unit
Piping Bundle
Manifold Valve
Pressure
Lo Hi
Gauge
Lo=Open Hi=Close
Charge Hose
Vacuum Pump
REFRIGERANT PIPING CONNECTIONS
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Figure 55: Removing the Service Valve Caps on
LSU090-120HSV4 Outdoor Units
2-way valve
(Close)
Figure 56: Removing the Service Valve Caps on
LSU180HSV4 Outdoor Units
3-way valve(Close) 3-way valve(Close)
2-way valve(Close) 2-way valve(Close)
• Be sure to use a manifold valve for air purging. If it is not available,
use a stop valve for this purpose.
• Be sure that the knob of the three-way valve is always kept close.
Table 18: Evacuation Table
Evacuation Table*
Tubing = Less than 33 ft.
10 minutes or more
* Required time for evacuation when 30 gal/h vacuum pump is used.

Air Purging

Liquid side
Gas side
Cap
3-way valve
(Close)
Evacuation
Outdoor Unit
Gas side
Liquid side
Valve
Caps
Tubing = More than 33 ft.
15 minutes or more
35