Trane ODYSSEY TTA 075 ED Installation Operation & Maintenance page 7

Refrigerant Piping Procedures
(Outdoor units)
Each TTA unit ships with dry nitrogen
holding charge. Due to this minimal
amount, we recommend that it be
removed and the entire system
evacuated (at the proper time) to avoid
possible contamination.
1. Remove the compressor service
access panel.
2. Locate the liquid and suction line
service valves. Check that the
piping connection stubs on the
valves (Figure 1) line up properly
with the holes in the unit cabinet.
3. Front-seat (close) both of the
service valves must be closed
before the system is opened.
4
Caution: Fully close the liquid and
suction line service valves before
puncturing the seal caps on the
connection stubs. If the seal caps are
punctured with the valves open, the
refrigerant contained in each circuit
will be lost.
4
Warning: Do not heat the seal caps
unless they have been punctured. If
caps are intact, application of heat
may generate excessive pressure in
the connection stub, causing personal
injury or death due to rupturing of
components and damage to the
service valve.
4. Heat and remove the seal caps.
4
Caution: Do not remove the seal
caps from refrigerant connections
unit prepared to braze refrigerant
lines to the connections. Excessive
exposure to atmosphere may allow
moisture or dirt to contaminate the
system, damaging valve seats and
causing ice formation in system
components.
5. Cut, fit and braze tubing, starting
at the outdoor unit and work toward
the indoor unit.
Note: Use long radius ells for all 90
degree bends.
TTA-R407C-EN1113
TTA-R407C-EN1113.indd 7 TTA-R407C-EN1113.indd 7
Refrigerant Piping Guidelines
All brazing should be done using 2
to 8 psig dry nitrogen purge flowing
through the pipe being brazed 9
(Figure 2).
4
Caution: Install a regulating valve
between the nitrogen source and
the gauge manifold (Figure 2).
Unregulated pressures can damage
system components.
4
Caution: Wet-wrap all valves and
protect painted surfaces from
excessive heat. Heat can damage
system components and the unit
finish.
6. Shut off nitrogen supply.
7. Shut off the manifold valve for
the line that is connected to the
suction line service valve.
Disconnect the line from the gauge
port on the value.
Refrigerant Piping Procedure
(Indoor Unit)
Once liquid and suction lines are
complete to the refrigerant
connections on the indoor unit, heat
and remove the seal caps on the
indoor unit connection stubs to
release the dry nitrogen charge.
Suction Line Service Valve
Note: Detail Service valve see Fig.1
Manifold
Gauge
Figure 2
1. Remove both seal caps from the
indoor unit connection stubs.
4
Caution: Do not remove seal caps
until prepared to braze refrigerant lines
to the connections. Extended exposure
to atmosphere may allow moisture or
dirt to contaminate the system,
damaging system components.
2. Turn nitrogen supply on. Nitrogen
enters through the liquid line
gauge port.
3. Braze the liquid line connections.
4. Open the gauge port on the suction
line and then braze suction line to
the connection stub. Nitrogen will
bleed out the open gauge port on
the suction line.
5. Shut off nitrogen supply.
Leak Check
After the brazing operation of
refrigerant lines to both the outdoor
and indoor unit is completed, the field
brazed connections must be checked
for leaks. Pressurize the system
through the service valve with dry
nitrogen to 200 psi. Use soap bubbles
or other leak-checking methods to
ensure that all field joints are leak free.
If not, release pressure, repair and
repeat leak test.
Suction Line Gauge Port
Liquid Line Service Valve
Note: Detail Service valve see Fig.1
Liquid Line
Gauge Port
Dry
Nitrogen
Supply
Pressure
Regulating
Valve
7
12-Sep-16 13:28:23 12-Sep-16 13:28:23