506762-01
Page 7 of 24
Issue 1143
Brazing Connection Procedure
1.
Cut ends of refrigerant lines square (free from nicks or
dents). Debur the ends. The pipe must remain round;
do not pinch end of line.
2.
Before making line set connections, use dry nitrogen to purge
the refrigerant piping. This will help to prevent oxidation and
the introduction of moisture into the system.
3.
Use silver alloy brazing rods (5% or 6% silver alloy for
copper-to-copper brazing or 45% silver alloy for copper-
to-brass or copper-to-steel brazing) which are rated for
use with R-410A refrigerant.
4.
Remove the Schrader core assemblies before brazing
to protect them from damage due to extreme heat.
Replace the cores when brazing is complete.
5.
Remove light maroon washers from service valves and
shield light maroon stickers to protect them during brazing.
Wrap a wet cloth around the valve body and copper tube
stub to protect it from heat damage.
6.
Braze the line set to the service valve. Quench the joints
with water or a wet cloth to prevent heat damage to the
valve core and opening port.
The tube end must stay
bottomed in the fitting during final assembly to ensure
proper seating, sealing, and rigidity.
7.
Install the fixed orifice ( or thermal expansion valve which
is sold separately and which is approved for use with R-
410A refrigerant) in the liquid line at the indoor coil (see
Refrigerant Metering Device on page 8).
Flushing Existing Line Set and Indoor Coil
This procedure should not be performed on systems
which contain contaminants, such as compressor burn
out.
Required Equipment
The following equipment is needed to flush the existing line
set and indoor coil (see Figure 8): Two clean R-22 recovery
bottles, an oil-less recovery machine with a “pump down”
feature, and two sets of gauges (one for use with R-22 and
one for use with R-410A).
Figure 8
Flushing Connections
Note:
The inverted R22 cylinder must contain at least the
same amount of refrigerant as was recovered from
the existing system.
When flushing existing line set and/or indoor coil, be sure to
empty all existing traps. Residual mineral oil can act as an
insulator, preventing proper heat transfer. It can also clog
the thermal expansion valve, reducing system performance
and capacity. Failure to properly flush system as explained
in these instructions will void warranty.
CAUTION
