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DC Inverter Multi
VRF Service Manual
The copper pipe shall not be inserted into the branch pipe too deep.
Copper pipe
Branch pipe
Correct connection
Wrong connection
5�7 Welding of Copper Pipe
5.7.1 Braze welding
Materials for braze welding
There are two kinds of braze welding, soft braze welding and hard braze welding. Hard braze welding is required in
this case.
Selection of braze welding
Red copper + red copper:brazing ller metal is Bcu93P(GB 6418),and welding ux is not needed.
Flame ux: capable of preventing the surface of copper pipes from oxidation, recommended for use.
Temperature for braze welding:820-860
(copper pipe becomes light red)
5.7.2 Safety acknowledgement before operation
a. Roll calling of construction personnel and conrmation on their health status.
b. Acknowledgement on work suits(helmets, clothes, safety bags and safety shoes)
c. Description of work location and environment.
d. Job division shall be made. Job content, method and order shall be indicated. Risk prediction activities shall be
performed.
e. “Construction Schedule” shall be worked out.
f. Head of each group shall be assigned
g. Risks of occurrence of an accident such as electric shock or re shall be indicated.
h. Instructions on how to use electric machinery properly shall be available.
i. Locations marked with “Staff Only” shall be indicated.
j. An application is necessary for use of open ame and shall be reviewed by on-site safety ofcer for approval.
k. Instructions given by re authorities shall be accepted in accordance with local laws and regulations.
l. Tools shall be sorted and counted. Upon knocking off for the day, tools shall be sorted and counted. If necessary,
the piping system shall be charged with coolant to avoid exhaustion.
6.7.3 Attention
a. Construction personnel must have relevant operation qualication.
Flame operation must be undertaken by qualied persons in accordance with local laws and regulations.
b. Wear coveralls (cotton for the best), safety shoes, safety helmet, leather gloves, protective goggles and anti-dust
mask.
Welding torch with back re arrestor shall be used to ensure safety.
c. Take care not to be burned by ame and heating parts.
d. Gas cylinder shall be handled carefully to prevent leakage.
e. Combustible substances in the surrounding areas shall be moved away. If movement is impossible, re proong
treatment shall be taken properly, such as being covered by ame-proof enclosure.
f. Good ventilation is necessary to avoid breathe in of harmful gas.
g. Appropriate measures shall be taken if there is a safety problem.
h. Operation on connectors of branch pipes as well as on the surrounding of pipe ends shall be performed on the
ground as possible, because heating is difcult to control at a high place and welded part of a branch pipe is prone to be
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