Installation
Maximum compressor test pressure (low side)
SM/SZ 084 - 185: 25 bar (g)
SY240 to 380: 22 bar (g)
Maximum compressor test pressure (high side)
32 bar (g)
Maximum pressure difference between high and
low side of the compressor:
24 bar
System pressure test
Pressurize the system on HP side first then LP side
to prevent rotation of the scroll. Never let the
pressure on LP side exceed the pressure on HP
side with more than 5 bar.
On SY/SZ240-300 models which have an internal
non return-valve in discharge fitting or if an
external non return valve is present on the
discharge line, we advise to pressurize the system
not quicker than 4.8 bar/s to allow enough
pressure equalisation between LP and HP side
over the scroll elements.
Always use an inert gas such as nitrogen for
pressure testing. Never use other gasses such as
oxygen, dry air or acetylene as these may form
an inflammable mixture. Do not exceed the
following pressures:
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 used for the large
scroll, a double tipped torch using acetylene is
recommended for the S240-300-380 brazing
operation.
For rotolock version compressors, solder sleeves
are available. 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.
• Apply heat evenly to Area A until the brazing
temperature is reached. Move the torch to
Area B and apply heat evenly until the brazing
temperature has been reached there as well, and
then begin adding the brazing material. Move
the torch evenly around the joint, in applying
only enough brazing material to flow the full
circumference of the joint.
• Move the torch to Area C only long enough to
draw the brazing material into the joint, but not
into the compressor.
• Remove all remaining flux once the joint has
been soldered with a wire brush or a wet cloth.
Remaining flux would cause corrosion of the
tubing.
In addition, for discharge connections equipped
with a non return valve integrated in discharge
fitting (SY/SZ240-300) the direction of the
torch has to be as described on the picture, and
maximum brazing time should be less than 2
minutes to avoid NRVI damages.
Ensure that no flux is allowed to enter into the
tubing or compressor. Flux is acidic and can cause
substantial d amage to the internal parts of the
system and compressor.
The polyolester oil used in SY / SZ compressors
is highly hygroscopic and will rapidly absorb
moisture from the air. The compressor must
therefore not be left open to the atmosphere
for a long period of time. The compressor fitting
plugs shall be removed just before brazing the
compressor.
Before eventual unbrazing the compressor or
any system component, the refrigerant charge
must be removed from both the high and low
pressure sides. Failure to do so may result in
serious personal injury. Pressure gauges must be
used to ensure all pressures are at atmospheric
level.
For more detailed information on the appropriate
materials required for brazing or soldering, please
contact the product manufacturer or distributor.
For specific applications not covered herein,
please contact Danfoss Commercial Compressors
for further information.
heat shield
C B
A
44
AB237986441643en-010801
Application Guidelines
Summary of Contents for R134a
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