R410a DC Inverter 60Hz
Carrier service manual
126
Installation
appear on the inner side of the pipe, and the pipe may easily get broken.
4) Ensure that the pipe does not sink during the bending process; ensure that the cross section of the bending
pipe is larger than 2/3 of the original area, otherwise it cannot be used.
the pipe sink easily on the side
twinkle will easily appear on this side
3.1.4 Brazing welding operation
3.1.4.1 Selecting refrigerant pipe
1. All pipe use shall comply with national or local standards (for example, pipe diameter, material,
thickness, etc.)
2. Specification: Seamless phosphorus to oxygenate copper pipe
3. Try best to use straight pipe or coil and avoid too much brazing welding.
Note: Select the pipes according to the pipe diameters shown below (O—coil, 1/2H—straight pipe)
Outer
Diameter
Material
Minimum
Thickness
Outer Diameter
Material
Minimum
Thickness
Outer Diameter
Material
Minimum
Thickness
1/4" (6. 4)
O
0. 8
3/4’’(Ф19. 0)
O
1. 0
1-1/2’’(Ф38. 0)
1/2H
1. 5
3/8" (9. 53)
O
0. 8
55/64’’(Ф22. 0)
1/2H
1. 2
1-49/64’’(Ф45. 0)
1/2H
1. 5
1/2" (12. 7)
O
0. 8
63/64’’(Ф25. 0)
1/2H
1. 2
2-1/8’’(Ф54. 0)
1/2H
1. 8
5/8"(Ф15. 9)
O
1. 0
1-1/8’’(Ф28. 6)
1/2H
1. 3
2-41/64’’(Ф67. 0)
1/2H
1. 8
3.1.4.2 Nitrogen filling for protecting copper pipe during brazing welding
1. Purpose: Avoid oxide scale from appearing on the inner wall of the copper pipe in the high
temperature
2. Risks of non-protective welding:
If no sufficient nitrogen is charged into the refrigerant pipe being welded, oxides will be generated on the
inner wall of the copper pipe. These oxides will block the refrigerant system, which will lead to all kinds of
malfunctions such as burn-out the compressor, poor cooling efficiency.
To avoid these problems, charge nitrogen continuously into the refrigerant pipe during the brazing
welding, and ensure that the nitrogen passes through the operating point until the welding is completed
and the copper pipe cools down completely. The schematic diagram for nitrogen charging is shown
below.