Danfoss MLM Series Application Manuallines page 43

Application Guidelines
Compressor connection
Installation
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. 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).
• Use only clean refrigeration-grade copper
tubing and clean all connections.
• Purge nitrogen 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.
Ensure that no flux is allowed to enter into the
tubing or compressor. Flux is acidic and can cause
MLZ/MLM015-026
MLZ/MLM030-045
MLZ/MLM048
MLZ/MLM058-076
substantial damage to the internal parts of the
system and compressor.
The PVE oil used in MLZ 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 for further information.
connection
ODF tube
Suction
Discharge
Suction
Discharge
Suction
Discharge
Suction
Discharge
Heat shield
C
Brazed Rotolock
connection
sizes
3/4"
1/2"
7/8"
1/2"
7/8"
3/4"
1"1/8
7/8"
FRCC.PC.015.A8.02
B A
1"1/4
1"
1"1/4
1"
1"1/4
1"1/4
1"3/4
1"1/4
43