DC Inverter Air
5. Laying of Refrigerant Pipes
1) Laying of Refrigerant Pipes
The system shall be clear and a system sign shall be marked at some distance to avoid the improper
connection.
2) Protection of Outdoor Refrigerant Pipes
In addition to the insulation layer, some outdoor refrigerant pipes shall be subject to the treatment
against the expected damage. If the length of exposed outdoor refrigerant pipe is over one meter, the
exposed pipe must be equipped with a pinch plate for protection.
3) Laying Principle of Refrigerant Pipes
A. It shall adopt the centralized arrangement, arrangement along the wall and the arrangement using
the corridor.
B. After completing the laying, it shall be wrapped with the white wrapping tapes. All pipes shall be
wrapped together according to the thickness of main pipeline on the basis of independent
wrapping for individual pipes, and no sense of relaxation shall prevail for their wrapping tightness.
C. The connecting pipes and electric wires of indoor/outdoor units (power cords, control lines) shall
be in principle arranged along the walls, turned reasonably, be smoothly vertical and horizontal,
parallel to each other and bound together to try the best to avoid the overhead cross and
blockage;
D. The installation of connecting pipes and electric wires of indoor/outdoor units (power cords,
control lines) shall in principle try the best to reduce the length of the pipeline;
E. It is necessary to try the best to wrap all pipes and the joints cannot be exposed;
4) Precautions for Laying of Refrigerant Pipes
A. Pipe Inserting: add the system number on the pipe to avoid the wrong connection of pipes;
B. Confirm the support strength for pipes.
Note: A return oil elbow must be equipped for each drop of 10m in the vertical height of
refrigerant pipe!
6. Adding of Refrigerant
Calculate required refrigerant according to length of liquid pipe
1) Charging Step of Refrigerant
A. The completion condition of vacuum drying can be determined based on evacuation or vacuum‐
pumping operation;
B. Calculate the weight of added refrigerant. When the piping length is longer than the actual standard
length for delivery:
(1) Valid length of pipe = pipe length + (elbow number× elbow equivalent length)
(2) Conversion of elbow equivalent length
Calculation of Adding Amount of Refrigerant
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