TTA-R407C-EN1113
7
Refrigerant Piping Guidelines
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.
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.
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.
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.
All brazing should be done using 2
to 8 psig dry nitrogen purge flowing
through the pipe being brazed 9
(Figure 2).
between the nitrogen source and
the gauge manifold (Figure 2).
Unregulated pressures can damage
system components.
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.
1. Remove both seal caps from the
indoor unit connection stubs.
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.
4
Caution:
Fully close the liquid and
4
Warning:
Do not heat the seal caps
4
Caution:
Do not remove the seal
4
Caution:
Install a regulating valve
4
Caution:
Wet-wrap all valves and
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.
Figure 2
Manifold
Gauge
Pressure
Regulating
Valve
Dry
Supply
Nitrogen
Liquid Line
Gauge Port
Liquid Line Service Valve
Note: Detail Service valve see Fig.1
Suction Line Service Valve
Note: Detail Service valve see Fig.1
Suction Line Gauge Port
TTA-R407C-EN1113.indd 7
TTA-R407C-EN1113.indd 7
12-Sep-16 13:28:23
12-Sep-16 13:28:23
