Installation
Each MLZ/MLM compressor is shipped with
printed 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
installation. The compressor must be handled
with caution in the vertical position, with a
maximum inclination of 15° from vertical. Store
the compressor between -35°C and 55°C, not
exposed to rain or corrosive atmosphere.
Each compressor is shipped with a nominal dry
nitrogen holding charge between 0.4 bar and
0.7 bar, 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 connecting 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, solder and flux, have a negative
impact on compressor 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
contamination 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 compressors are delivered with 4 rubber
grommets and metal sleeves. Compressors
must always be mounted with these grommets.
Recommended torque for mounting bolts: 11 Nm
(±1 Nm).
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
contamination, 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.
Recommended brazing procedures and material,
are described on following page.
42
FRCC.PC.015.A8.02
Application Guidelines
