A
PPLICATION
GUIDELINES
I
NSTALLATION
Each MLZ/MLM compressor is shipped with print-
ed Instructions for installation. These Instructions
can also be downloaded from our web site
www.danfoss.com or directly from:
http://instructions.cc.danfoss.com
Compressor handling and
storage
Compressor holding
charge
Compressors are provided with a lifting lug. This
lug should always be used to lift the compressor.
Once the compressor is installed, the lifting lug
should never be used to lift the complete instal-
lation. The compressor must be handled with cau-
tion in the vertical position, with a maximum incli-
nation of 15° from vertical. Store the compressor
between -31°F and 131°F, not exposed to rain or
corrosive atmosphere.
Each compressor is shipped with a nominal dry ni-
trogen holding charge between 6 and 10PSI, and
is sealed with elastomer plugs. The plugs should
be removed with care to avoid oil loss when the
holding charge is released. Remove the suction
plug first and the discharge plug afterwards. The
plugs shall be removed only just before connect-
ing the compressor to the installation in order to
avoid moisture entering the compressor. When
the plugs are removed, it is essential to keep the
compressor in an upright position to avoid oil
spillage.
System cleanliness
The refrigeration system, regardless of the type of
compressor used, will only provide high efficiency
and good reliability, along with a long operating
life, if the system contains solely the refrigerant
and oil it was designed for. Any other substances
within the system will not improve performance
and, in most cases, will be highly detrimental to
system operations.
The presence of non-condensable substances and
system contaminants, such as metal shavings, sol-
der and flux, have a negative impact on compres-
sor service life. Many of these contaminants are
small enough to pass through a mesh screen and
can cause considerable damage within a bearing
assembly. The use of highly hygroscopic PVE oil in
MLZ compressors requires that the oil be exposed
to the atmosphere just as little as possible.
During the manufacturing process, circuit con-
tamination may be caused by:
• Brazing and welding oxides,
• Filings and particles from the removal of burrs in
pipe-work,
• Brazing flux,
• Moisture and air.
Compressor mounting
Maximum inclination from the vertical plane, while
operating must not exceed 7 degrees. All com-
pressors are delivered with 4 rubber grommets
and metal sleeves. Compressors must always be
mounted with these grommets. Recommended
torque for mounting bolts: 100 lbf-in (±10 lbf-in).
Brazing material
For copper suction and discharge fittings, use
copper-phosphorus brazing material. Sil-Fos® and
other silver brazing materials are also acceptable.
If flux is required for the brazing operation, use
coated rod or flux core wire. To avoid system con-
tamination, do not brush flux on.
Tube brazing procedure
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. Recommend-
ed brazing procedures and material, are described
on following page.
33
FRCC.PC.016.A1.22
