SERVICING
21
At any time the system has been open for repair, the
factory installed liquid line filter drier must be replaced.
Brazing Materials
Copper to Copper Joints
- Sil-Fos used without flux
(alloy of 15% silver, 80% copper, and 5% phosphorous).
Recommended heat 1400°F.
Copper to Steel Joints
- Silver Solder used without
a flux (alloy of 30% silver, 38% copper, 32% zinc).
Recommended heat - 1200°F.
Standing Pressure Test (Recommended Before
System Evacuation)
WARNING
To avoid the risk of fire or explosion, never use oxygen,
high pressure air or flammable gases for leak testing of a
refrigeration system.
WARNING
To avoid possible explosion, the line from the nitrogen
cylinder must include a pressure regulator and a pressure
relief valve. The pressure relief valve must be set to open at
no more than 450 PSIG.
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.
Leak Testing (nitrogen or nitrogen-traced)
WARNING
To avoid the risk of fire or explosion, never use oxygen,
high pressure air or flammable gases for leak testing of a
refrigeration system.
WARNING
To avoid possible explosion, the line from the nitrogen
cylinder must include a pressure regulator and a pressure
relief valve. The pressure relief valve must be set to open at
no more than 450 PSIG.
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
for refrigerant identification). Using dry nitrogen, finish
charging the system 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
REFRIGERANT UNDER PRESSURE!
Failure to follow proper procedures may cause property
damage, personal injury or death.
NOTE: Scroll compressors should never be used
to evacuate or pump down a heat pump or air
conditioning system.
CAUTION
Prolonged operation at suction pressures less than 20
PSIG for more than 5 seconds will result in overheating of
the scrolls and permanent damage to the scroll tips, drive
bearings and internal seal.
LOW SIDE
GAUGE
AND VALVE
HIGH SIDE
GAUGE
AND VALVE
Evacuation
