GENERAL INFORMATIONPRODUCT INFORMATIONSYSTEM DESIGNORDERING INFORMATION INTEGRATION INTO SYSTEM
Assembly line procedure
Piping assembly Good practices for piping assembly is a pre-requisite to ensure compressor life time (system
cleanliness, brazing procedure etc.)
System cleanliness
Circuit contamination possible cause: Requirement:
Brazing and welding oxides During brazing, flow nitrogen through the system.
Particles and burrs
Remove any particles and burrs generated by tube
cutting and hole drilling.
Moisture and air
Use only clean and dehydrated refrigeration grade
copper tubing.
Opened compressor must not be exposed to air more
than 20 minutes to avoid moisture captured by oil.
Brazing procedure:
• Brazing operations must be performed by
qualified personnel.
• Make sure that no electrical wiring is connected
to the compressor.
• To prevent compressor shell and electrical box
overheating, use a heat shield and/or a heat-
absorbent compound.
• Clean up connections with degreasing agent
• Flow nitrogen through the compressor.
• Use flux in paste or flux coated brazing rod.
• Use brazing rod with a minimum of 5% silver
content.
• It is recommended to use double-tipped torch
using acetylene to ensure a uniform heating of
connection.
• For discharge connections brazing time should
be less than 2 minutes to avoid NRVI damages
if any.
• To enhance the resistance to rust, a varnish on
the connection is recommended.
Before eventual un-brazing of the
compressor or any system component, the
refrigerant charge must be removed.
System pressure test and
leak detection
The compressor has been strength tested
and leak proof tested (<3g/year) at the factory.
For system tests:
• Always use an inert gas such as Nitrogen or
Helium.
• Pressurize the system on HP side first then LP
side.
• Do not exceed the following pressures indicated
in table below
*On DSH240-295-381-485 (models with internal
non return valve in discharge fitting), or if an
external non return valve is present on the
discharge line, the maximum pressurizing
speed must be respected to ensure pressure
equalization between LP and HP side over scroll
elements.
Maximum compressor test
pressures
DSH090-105-120-140-161-184 DSH240-295 -381-485
Maximum compressor test
pressure high side (HP)
48.7bar (g) (706psig)
HP-LP<37bar (537psi)
Maximum compressor test
pressure low side (LP)
33.3 bar (g) (483psig)
LP-HP<5bar (73psi)
Maximum speed 4.8bar/s (70psi/s)
34.3bar (497psi)
LP – HP <5bar (73psi)
Maximum speed 4.8bar/s (70psi/s)*
heat shield
C
B
A
51FRCC.PC.045.A7.02
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