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Installation Instructions
3.
Nitrogen charging for pressure maintaining and leak detection
After the evaporator of the indoor unit is connected to the connector pipe (after welding), nitrogen more than
4.0MPa shall be charged inside the evaporator and the piping connected to evaporator with a nitrogen cylinder
(adjusted by a reducing valve). Afterwards, the valve of the nitrogen cylinder shall be closed, for leak detection
with soapy water or leak detecting solution. The pressure shall be maintained for more than 5 minutes, and then
whether the system pressure is reduced or not shall be observed. In case the pressure is reduced, leakage can be
identified. After the leak point is handled, the steps above shall be repeated.
After the evaporator of the indoor unit is connected to connecting piping, nitrogen shall be charged for
pressure maintaining and leak detection. Afterwards, the evaporator shall be connected to the two-way stop valve
and three-way stop valve of the outdoor unit. After the copper cap of the connecting piping is fastened, nitrogen
more than 4.0MPa shall be charged at the access hole of the three-way stop valve with a charging hose. The valve
of the nitrogen cylinder shall be closed, for leak detection with soapy water or leak detecting solution. The
pressure shall be maintained for more than 5 minutes, and then whether the system pressure is reduced or not shall
be observed. In case the pressure is reduced, leakage can be identified. After the leak point is handled, the steps
above shall be repeated.
The operation above can also be completed after the indoor unit is connected to the connecting pipelines and
the two-way stop valve and three-way stop valve of the outdoor unit, after the access hole of the outdoor unit is
connected to the nitrogen cylinder and pressure gauge and after more than 4.0MPa nitrogen is charged. No leak
points are identified in the leak detection at the joint/welding junction of the indoor unit and at the joint of
connecting pipelines of the two-way stop valve and three-way stop valve of the outdoor unit. It must be
guaranteed that each joint is available for leak detection during installation.
The next step (vacuumizing with a vacuum pump) can only be continued after the installation steps (nitrogen
charging for pressure maintaining and leak detection normal) are completed.
•
Outdoor Unit Installation
1.
Fixation and connection
Note:
a)
Fire source shall be avoided within 3m around the place of installation.
b)
The leak detection equipment of refrigerant shall be placed at a low position in the
outdoor, and shall be opened.
1)
Fixation
The support of the outdoor unit shall be fixed onto the wall surface, and then the outdoor unit shall be fixed onto
the support horizontally. In case the outdoor unit is wall-mounted or roof-mounted, the support shall be firmly
fixed, to avoid the damage of strong wind.
2)
Installation of connecting pipes
The cone of the connecting pipes shall be aligned with the conical surface of corresponding valve connector.
The nut of connecting pipes shall be installed at a proper position and then be tightened with a spanner. Excessive
tightening torque shall be avoided, or otherwise the nut may be damaged.
•
Vacuumizing
A digital vacuum gauge shall be connected for vacuumizing. The duration of vacuumizing shall be at least 15
minutes, and the pressure of the vacuum gauge shall be below 60Pa.Afterwards, the vacuumizing equipment shall
be closed, and whether the reading of the digital vacuum gauge is increased or not shall be observed after the
pressure is maintained for 5 minutes. In case no leakage is identified, the two-way stop valve and three-way stop
valve of the outdoor unit may be opened. Finally, the vacuumizing hose connected to the outdoor unit can be
disassembled.
•
Leak Detection
The joint of connecting pipes for the outdoor unit shall be subject to leak detection with soap bubble or
dedicated leak detection equipment.
6
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