1.
Piping assembly
Tubing
Only use clean and dehydrated refrigeration grade copper tubing. Tube-cutting must be carried out so as not to
deform the tubing roundness and to ensure that no foreign debris remains within the tubing. Only refrigerant grade
fittings should be used and these must be of both a design and size to allow for a minimum pressure drop through
the completed assembly. Follow the brazing instructions on next pages. Never drill holes into parts of the pipe-work
where filings and particles can not be removed.
Brazing and soldering
Do not bend the compressor discharge or suction lines or force system piping into the compressor connections,
because this will increase stresses that are a potential cause of failure. Recommended brazing procedures and
material, are described section Compressor connection. These operations must be performed by a qualified
personnel in compliance with all pertinent practices and safety procedures.
Copper to copper
When brazing copper-to-copper connections, the use of copper/phosphorus brazing alloy containing 5% silver or
more with a melting temperature of below 800°C is recommended. No flux is required during brazing.
Dissimilar metals
When manipulating dissimilar metals such as copper and brass or steel, the use of silver solder (5% or more) and
anti-oxidant flux is necessary. Please contact Danrfoss Technical support for any deviation from this guidelines.
Compressor connection
When brazing the compressor fittings, do not overheat the compressor shell, which could severely damage certain
internal components due to excessive heating. Use of a heat shield and/or a heat-absorbent compound is highly
recommended. Due to the relatively sizable tubing and fitting diameters a double-tipped torch using acetylene is
recommended for brazing operation on CH scroll compressors.
Figure 29: Brazing the compressor fittings
C
C
-0
0
0
0
5
2
1
C
B
A
Heat shield
For brazing the suction and discharge connections, the following procedure is advised:
• Make sure that no electrical wiring is connected to the compressor.
• Protect the terminal box and compressor painted surfaces from torch heat damage (see diagram).
• Remove the Teflon gaskets when brazing rotolock connectors with solder sleeves.
• Use only clean refrigeration-grade copper tubing and clean all connections.
• Use brazing material with a minimum of 5% silver content.
• Purge nitrogen or CO
2
through the compressor in order to prevent against oxidation and flammable conditions.
The compressor should not be exposed to the open air for extended periods.
• Use of a double-tipped torch is recommended.
Scroll compressors, CH290 and CH485 | Application
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