Refrigerant Piping Installation - LG Multi V PRHR033 Installation Manual

10
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 o
ccurred and it is a leakage cause.
CAUTION
!
1 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.
2 Always use a pressure reducing valve.
3 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
WARNING
!
Always use extreme care to prevent the refrigerant gas (R410A)
from leakage while using fire or flame. If the refrigerant gas comes
in contact with the flame from any source, such as a gas stove, it
breaks down and generates a poisonous gas which can cause gas
poisoning. Never perform brazing in an unventilated room. Always
conduct an inspection for gas leakage after installation of the
refrigerant piping has been completed.
Regulator
Nitrogen gas Pressure
0.02 MPa (2.9 psi) less
Auxiliary valve
Taping
(Should not
contain air)
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)
Open status when both the pipe and the valve are
in a straight line.
Cut both the pipe and the valve with a cutter to suit
the length
[Don't cut the length of less than 70 mm (2-3/4")]
CLOSE OPEN
WARNING
!
After completing work, securely tighten both service ports and
caps so that gas does not leak.
Ball Valve
Elbow
(Liquid Pipe)
① Pipe joint (auxiliary parts): Securely perform brazing with a nitrogen
blow into the service port.(Releasing pressure : 0.02 MPa (2.9 psi)
or less)
② Cap: Remove caps and operate valve, etc. After operation, always
reattach caps (tightening torque of valve cap: 25 N·m (250 kg·cm) or
more). (Don't remove the internal part of the port)
③ Service port: Make the refrigerant pipe vacuum and charge it using
the service port. Always reattach caps after completing work
(tightening torque of service cap: 14 N·m (140 kg·cm) or more).
④ Liquid pipe
⑤ Gas pipe
⑥ Elbow joint (field supply)
h Remove the front panel before pipe
connection
h Must check the pipe (liquid pipe, low
pressure gas pipe, high pressure gas
pipe) before pipe connection
Ball Valve(Gas Pipe)
Low pressure g
High pressure g
Liquid pipe
Low pressure gas pipe Low pressure gas pipe Low pressure gas pipe
High pressure gas pipe High pressure gas pipe High pressure gas pipe