GSZH5 Service Manual
95
SERVICING
5. When brazing, sweep the tubing with dry nitrogen to
prevent the formation of oxides on the inside surfaces.
6. Complete any repair by replacing the liquid line drier in
the system, evacuate and charge.
Brazing Materials
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.
recommended to avoid burning the serial plate or the
to protect heat sensitive components such as service
valves and TXV valves.
Copper to Copper Joints
(alloy of 15% silver, 80% copper, and 5% phosphorous).
Recommended heat 1400°F.
Copper to Steel Joints - Silver Solder used without
Recommended heat - 1200°F.
WARNING
WARNING
Using dry nitrogen, pressurize the system to 450 PSIG.
Allow the pressure to stabilize and hold for 15 minutes
(minimum). If the pressure does not drop below 450 PSIG
the system is considered leak free. Proceed to system
evacuation using the Deep Vacuum Method. If after 15
minutes the pressure drops below 450 PSIG follow the
procedure outlined below to identify system leaks. Repeat
the Standing Pressure Test.
WARNING
WARNING
Leak test the system using dry nitrogen and soapy
water to identify leaks. If you prefer to use an electronic
leak detector, charge the system to 10 PSIG with the
appropriate system refrigerant (see Serial Data Plate
to 450 PSIG. Apply the leak detector to all suspect areas.
When leaks are discovered, repair the leaks, and repeat
the pressure test. If leaks have been eliminated proceed to
system evacuation.
System Evacuation
Condensing unit liquid and suction valves are closed to
contain the charge within the unit. The unit is shipped with
the valve stems closed and caps installed. Do not open
valves until the system is evacuated.
WARNING
to evacuate or pump down a heat pump or air
conditioning system.
CAUTION
The Deep Vacuum Method requires a vacuum pump