Goodman GSX Series Installation & Operation Instructions page 4

The indoor coil is pressurized; the copper cap must be
punctured to permit a gradual escape of the pressure prior to
un-sweating those caps. Immediately couple the tubing to
the indoor unit to minimize exposing the coils to moisture.
REFRIGERANT LINE CONNECTIONS
IMPORTANT
To avoid overheating the
while brazing, wrap the component with a wet rag, or use a
thermal heat trap compound. Be sure to follow the
manufacturer's instruction when using the heat trap com-
pound.
NOTE: Remove Schrader valves from service valves before
brazing tubes to the valves. Use a brazing alloy of 2%
minimum silver content. Do not use flux. Torch heat required
to braze tubes of various sizes is proportional to the size of
the tube. Tubes of smaller size require less heat to bring the
tube to brazing temperature before adding brazing alloy.
Applying too much heat to any tube can melt the tube. Service
personnel must use the appropriate heat level for the size of
the tube being brazed.
NOTE: The use of a heat shield when brazing is recom-
mended to avoid burning the serial plate or the finish of the
unit.
NOTE: Be careful not to kink or dent refrigerant lines. Kinked
or dented lines will cause poor performance or compressor
damage. Do NOT make final refrigerant line connection until
plugs are removed from refrigerant tubing.
1. The ends of the refrigerant lines must be cut square,
deburred, cleaned, and be round and free from nicks or
dents. Any other condition increases the chance of a
refrigerant leak.
2. "Sweep" the refrigerant line with nitrogen or inert gas
during brazing to prevent the formation of copper-oxide
inside the refrigerant lines. The POE oils used in R-410A
applications will clean any copper-oxide present from
the inside of the refrigerant lines and spread it through-
out the system. This may cause a blockage or failure of
the metering device.
3. After brazing, quench the joints with water or a wet cloth
to prevent overheating of the service valve.
REFRIGERANT LINE LENGTH (METERS)
0-7.5
Cond
Unit Line Diameter OD (mm)
Tons Suct Liq
1 1/2 15.9 6.4
2 19.1 9.5
2 1/2 19.1 9.5
3 19.1 9.5
3 1/2 19.1 9.5
4 22.2 9.5
5 22.2 9.5
* - 19.1 mm REQUIRED FOR FULL RATINGS
^ - 22.2 mm REQUIRED FOR FULL RATINGS
service valves or expansion device
7.6-15.1 15.2-22.6
Suct Liq Suct
19.1 9.5 19.1
19.1 9.5 19.1
*19.1 9.5 22.2
22.2 9.5 22.2
22.2 9.5 28.6
28.6 9.5 28.6
28.6 9.5 28.6
4. Ensure the filter drier paint finish is intact after brazing. If
the paint of the steel filter drier has been burned or
chipped, repaint or treat with a rust preventative. This is
especially important on suction line filter driers which
are continually wet when the unit is operating.
NOTE: Before brazing, verify indoor piston size by checking
the piston kit chart packaged with indoor unit.
Leak Testing (Nitrogen or Nitrogen-Traced)
Pressure test the system to approximately 100 PSI with dry
nitrogen and use soapy water to locate leaks. If you wish to
use a leak detector, charge the system to 10 psi using the
appropriate refrigerant then use nitrogen to finish charging
the system to working pressure then apply the detector to
suspect areas. If leaks are found, repair them. After repair,
repeat the pressure test. If no leaks exist, proceed to system
evacuation.
System Evacuation
NOTE: Scroll compressors should never be used to evacu-
ate or pump down a heat pump or air conditioning system.
1. Connect the vacuum pump with 250 micron capability to
the service valves.
2. Evacuate the system to 250 microns or less using suction
and liquid service valves. Using both valves is necessary
as some compressors create a mechanical seal separat-
ing the sides of the system.
3. Close pump valve and hold vacuum for 10 minutes.
Typically pressure will rise during this period.
•
If the pressure rises to 1000 microns or less and
remains steady the system is considered leak-free;
proceed to startup.
Liq
•
If pressure rises above 1000 microns but holds steady
9.5
below 2000 microns, moisture and/or non-condensibles
9.5
may be present or the system may have a small leak.
12.7
Return to step 2: If the same result is encountered check
12.7
for leaks as previously indicated and repair as necessary
12.7
then repeat evacuation.
12.7
•
If pressure rises above 2000 microns, a leak is present.
12.7
Check for leaks as previously indicated and repair as
necessary.
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