Midea V4 Plus S Series User Manual

R410A All DC Inverter V4+S Series 60Hz MCAC-VTSM-2015-09
102 Installation
4.4 Brazing
4.4.1 Selecting refrigerant pipe
1. All pipe used shall comply with national or local standards (for example, pipe diameter, material, thickness,
etc.)
2. Specifications: Seamless phosphorus to oxygenate copper pipe
3. It is best to use straight pipe or coil and avoid excessive brazing.
Note: Select the pipes according to the pipe diameters shown below (O—coil, 1/2H—straight pipe)
Outer Diameter
in.(mm)
Material
Minimum
Thickness
in.(mm)
Outer
Diameter
Material
Minimum
Thickness
Outer Diameter
Material
Minimum
Thickness
Ф1/4(6. 35)
O
1/32(0. 8)
Ф3/4(19. 1)
O
3/64(1. 0)
Ф1-1/2(38. 1)
1/2H
1/16(1. 5)
Ф3/8(9. 52)
O
1/32(0. 8)
Ф7/8(22. 2)
1/2H
3/64(1. 2)
Ф1-3/4(44.5)
1/2H
1/16(1. 5)
Ф1/2(12. 7)
O
1/32(0. 8)
Ф1(25. 4)
1/2H
3/64(1. 2)
Ф2-1/8(54. 0)
1/2H
5/64(1. 8)
Ф5/8(15. 9)
O
3/64(1. 0)
Ф1-1/8(28. 6)
1/2H
3/64(1. 3)
Ф2-5/8(67. 0)
1/2H
5/64(1. 8)
4.4.2 Nitrogen filling to protect copper pipe during brazing
1. Purpose: Avoid oxide scale formation on the inner wall of the copper pipe caused by high temperature
2. Risks of non-protective welding:
If insufficient nitrogen is charged during brazing, oxides will form on the inner wall of the copper pipe. These
oxides will block the refrigerant system, which will lead to various malfunctions such as compressor burnout,
poor cooling efficiency.
To avoid these problems, charge nitrogen continuously into the refrigerant pipe during brazing, and ensure that
the nitrogen continuously passes through the operating point until the welding is completed and the copper
pipe cools down completely. The diagram for nitrogen charging is shown below.
copper pipe 1/4"
copper pipe fittings
copper pipe
hign pressure flexible pipe
valve
nitrogen charging connecting fitting
brazing weld part
oxygen nitrogen
3. Making nitrogen-charging pipe joint
When welding the pipe joint, connect the nitrogen-charging joint to the pipe fittings to be welded.
The nitrogen-charging joint is shown below:
4. Cautions for welding pipe fittings
1) Adopt transition pipe.
2) Charge nitrogen from the side of the short pipe, because short distance may result in perfectible nitrogen
replacement effect.

Midea V4 Plus S Series Specifications

General

Brand	Midea
Model	V4 Plus S Series
Category	Air Conditioner
Language	English