Connection Of Refrigerant Tubing - Trane TTD Series Installation Manual

1. The principal concerns in
refrigeration tubing are:
- Uniform oil return to the
compressor.
- Pressure drops and their effect on
system capacity.
- Tube routing and isolation to avoid
line breakage, vibration and sound
transmission. Regarding this, the
interconnecting refrigerant lines
should be simple and shorter as
much as possible.
2. Flare Connections
The units reported in this manual
employ the flare method to
interconnect refrigerant tubes between
indoor and outdoor units (Figure 2).
- The tube end of all refrigerant tubes
should be flared, the tube should
be cut and deburred. Be sure no
copper scraps fall in to the tube.
- Be sure to fit a cap to the open end
of the tube to keep it free of dust
and moisture.
- Avoid bending the tube. If it is
necessary, bend it gently, with a
radius of more than 3 or 4 cm.
(1 1/2 in. or 1 5/8 in.)
- Cut approximately 30 to 50 cm.
(12 in. to 20 in.) longer than
estimated tubing length.
- Before flaring remember to fit
the nut.
- Ream with tube end downward
to avoid copper scraps inside
the tube.
- Remove the flare caps on the
tube end.
- Connect the tubes by aligning
the centers of both flares and turn
the flare nuts by hand 3 or 4 turns
(Figure 3).
Flare nut
Union
Figure 3
8

Connection of Refrigerant Tubing

Service Port
Valve Cap
3. Insulate both lines, liquid (narrow
tube) and suction (wide tube), to
prevent heat loss and wet floor due to
dripping of chilled condensation.
Apply proper insulation material,
yy
minimum thickness should be 8 mm
(1/3 in.) (Figure 4).
yy yyy
Insulation Thickness
yy yyy
Min. 8 mm Min. 8 mm (1/3 in.)
Figure 4
Note
Do not try to bend the tube after
installation.
4. Finish with armoring tape.
Also see section of condensate drain
piping.
Note
Apply refrigeration oil on flare and
union surfaces before connecting
them. This will reduce refrigerant
leakage.
Tube
Connection
(Flare)
Figure 2
- Check the tubing connections and
refrigerant lines before applying
specified torque. Fasten flare nuts
as recommended below.
Table 4
Tube Diameter Tightening
mm. in.
6.35 (1/4)
9.52 (3/8)
12.70 (1/2)
15.88 (5/8)
Electrical Connection
Liquid Line System # 1
Gas Line System # 1
Liquid Line System # 2
Gas Line System # 2
Liquid Line System # 3
Gas Line System # 3
Torque
kg - cm lbs - in.
150 - 200 (130 - 170)
350 - 400 (300 - 340)
500 - 550 (430 - 470)
600 - 650 (520 - 570)
MS-SVN005-EN