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Installation
Due to our policy of continuous product innovation, some specications may change without notication.
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REFRIGERANT PIPING DESIGN
Pressure (Leak) Testing
Perform a Pressure (Leak) Test
1. Upon completion of refrigerant piping system installation, open all isolation ball valves throughout the piping system.
2. DO NOT apply power to the Outdoor, Indoor, and Heat Recovery Units (Heat recovery systems only). If power is applied, expansion
valves close and the pressure test will not be conclusive.
If power has been applied to any device before the pressure test, contact your LG Applied Rep champion or service technician for the
procedure to reopen the EEV valves.
3. DO NOT open the outdoor unit service valves; the factory refrigerant charge will be released.
4. Use medical grade dry nitrogen and pressure test the refrigerant piping system to a minimum of 550 psi for a period of 24 hours.
Pressurize the liquid, low pressure vapor, and medium pressure vapor (heat recovery systems only) concurrently.
Pressure (Leak) Testing for Heat Pump Systems
If the ambient temperature changed between the time when pressure was applied and when the pressure drop was checked, adjust results by
factoring in approximately 1.45 psi for each 2°F of temperature difference.
Correction formula = (Temperature when pressure was applied - Temperature when pressure drop was checked) x 0.01.
Example: When pressure (550 psig) was applied, temperature was 80.6°F; 24 hours later when pressure drop (540 psi) was checked, tempera-
ture was 68°F. Thus, 80.6 - 68 x 0.01 = 0.126. In this case, the pressure drop of 0.126 was due to temperature difference, therefore, there is no
leak in the refrigerant piping system.
During pressurization, the nitrogen gas cylinder must be positioned vertically to prevent the nitrogen from entering the refrigeration system in
its liquid state. Do not lay the nitrogen cylinder on its side.
Indoor unit
Nitrogen gas
Slave Unit Master Unit
Liquid pipe
Vapor pipe
Liquid pipe
Vapor pipe
Liquid side
Vapor side
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