Refrigerant Piping Installation; Precautions On Pipe Connection / Valve Operation - LG Multi V PRHR042A Installation Manual

12
Nitrogen substitution method
Welding, as when heating without nitrogen substitution a large
amount of the oxide film is formed on the internal piping.
The oxide film is a caused by clogging EEV, Capillary, oil hole of
accumulator and suction hole of oil pump in compressor.
It prevents normal operation of the compressor.
In order to avoid this problem, Welding should be done after replacing
air by nitrogen gas.
When welding plumbing pipe, the work is required.
Welding Point
Oxide scale
Note) should not block the outlet side.
When the internal pressure in pipe is abo
ve the atmospheric pressure, pinhole is
occurred and it is a leakage cause.
CAUTION
!
• Always use the nitrogen.(not use oxygen, carbon dioxide, and a
Chevron gas): Please use the following nitrogen pressure 0.02 MPa
(2.9 psi) Oxygen - Promotes oxidative degradation of refrigerant oil.
Because it is flammable, it is strictly prohibited to use Carbon
dioxide - Degrade the drying characteristics of gas Chevron Gas -
Toxic gas occurs when exposed to direct flame.
• Always use a pressure reducing valve.
• Please do not use commercially available antioxidant.
The residual material seems to be the oxide scale is observed. In
fact, due to the organic acids generated by oxidation of the
alcohol contained in the anti-oxidants, ants nest corrosion
occurs. (causes of organic acid → alcohol + copper + water +
temperature)
REFRIGERANT PIPING
INSTALLATION
For Heat Recovery System Installation

Precautions on Pipe connection / Valve operation

Pipe connection is done by connecting from the end of the pipe to the branching
pipes, and the refrigerant pipe coming out of the outdoor unit is divided at the end
to connect to each indoor unit. Flare connection for the indoor unit, and welding
connection for the outdoor pipe and the branching parts. (Including HR Unit)
* Pipes and wires should be purchased separately for installation of the product.
- Use hexagonal wrench to open/close the valve.
Regulator
Nitrogen gas
Pressure 0.02 MPa
(2.9 psi) less
Auxiliary valve
Taping
(Should not
contain air)
ARUB***GSS4
- Refer to the table below and install with the correct pipe diameter.
Heat Recovery
A[mm(inch)] Ø15.88(5/8)
B[mm(inch)] Ø9.52(3/8)
C[mm(inch)] Ø19.05(3/4)
ARUM***GSS5
- Refer to the table below and install with the correct pipe diameter.
Heat Recovery
A[mm(inch)] Ø9.52(3/8)
B[mm(inch)] Ø15.88(5/8)
C[mm(inch)] Ø19.05(3/4)
* In case of heat pump installation, please weld with the proper Low
pressure Gas pipe included with product.
Refrigerant
Charging Port
Low Pressure gas pipe
C
Liquid pipe B
High Pressure gas pipe
A
Heat Pump
-
-
-
Refrigerant
Charging Port
Service Port
Low Pressure
C
Gas pipe
High Pressure
B
Gas pipe
Liquid pipe
A
Heat Pump
Ø9.52(3/8)
Ø15.88(5/8)
Not Used*