Trane MCD/MWD-512 Installation & Operation Manual page 17

Screw/flare connections
CAUTION!
When cutting, deburring and
splaying the tubes, keep the end of
the tube down to make sure that
copper waste does not fall into the
lines.
Cut the copper tube using a pipe-
cutter only (do not use a metalsaw).
Hold the tube downwards when
deburring it.
Figure 5 - Deburring recommendations
SS-SVX07B-E4
Installation
Unscrew the Flare nuts which are
placed on the beginnings of the
indoor unit lines. Put the Flare nut
onto the tube. Splay the tube.
Connect the refrigerant tubes to the
indoor unit. Tighten the Flare nuts
using the recommended tightening
torques in Table 11. Insufficient
tightening will cause refrigerant
leaks. Use flat wrenches only (see
Figure 6). Repeat the operation for
each circuit.
Figure 6 - Tightening flare nuts
Table 11 -Recommended tightening
torques
Line diameter Tightening torque (kg/cm)
1/4'' 150-200
3/8'' 350-400
1/2'' 500-550
5/8'' 600-650
3/4'' 700-750
Brazed connections
These lines will be created on the
installation site. They will be
installed according to normal trade
practice by qualified personnel, in
compliance with local legislation.
1. Remove the plugs from the units'
refrigerant connections just before
connecting the piping, when all
the connections on the refrigerant
lines have been terminated. This
will prevent contamination by
humidity. Remove the rubber
plugs from the ends of the tubes.
2. Use a clean dry copper tube for
refrigeration installations.
3. Use silver brazing alloy only. Do
not overheat the welds and carry
out nitrogen scavenging inside the
tubes to prevent oxidization during
brazing.
4. Once all the other connections
have been made, debraze or cut
the plug on the outdoor unit's
refrigerant line connections.
Proceed in the same way as for
brazing of the indoor unit's lines.
Line insulation
To prevent heat losses and
condensation, both liquid and gas
lines must be thoroughly insulated.
17