26
Trane condensing units are shipped with a Nitrogen hold-
ing charge. If there is no pressure, the unit must be leak
tested to determine the location of leak as follows:
Note: These service procedures require working
with refrigerant, Do NOT release refrigerant to the
atmosphere! The service technician must comply
with all federal, state, and local laws. Refer to
general service bulletin MSCU-SB-1 (latest edition).
Use refrigerant gas as a tracer for leak detection and use
oil-pumped dry nitrogen to develop the required test pres-
sure. Test the high and low side of the system at pressures
dictated by local codes.
1. Close the field supplied liquid line service valve(s) in-
stalled near the evaporator and the compressor dis-
charge service valve to isolate the system's high side
from the low side. Pressure test the liquid line, discharge
line, and condenser coils at pressures dictated by local
codes. Do not exceed 10# above the pressure control
settings.
2. Connect a refrigerant cylinder to the charging port of the
liquid line service valve. Use the refrigerant to raise the
high side pressure to 12 to 15 psig.
3. Disconnect the refrigerant cylinder. Connect a dry nitro-
gen cylinder to the charging port and increase the high
side pressure. Do not exceed the condenser maximum
working pressure listed on the unit nameplate.
4. Use a halide torch, halogen leak detector or soap
bubbles to check for leaks. Check all piping joints,
valves, etc...
5. If a leak is located, use proper procedures to remove the
refrigerant/nitrogen mixture, break the connection and re-
make as a new joint. Retest for leaks after making re-
pairs.
6. Repeat the test procedure for the low side of the system,
charging through the suction pressure gauge port or
through an access provided on the suction line by the in-
staller. Increase the system pressure to 100 psig.
7. If a leak is located, use proper procedures to remove the
refrigerant/nitrogen mixture, break the connection and re-
make as a new joint. Retest for leaks after making re-
pairs.
8. Open the liquid line service valve and the compressor
discharge service valve.
the tubing during brazing, sweep an inert gas, such as
dry nitrogen, through the tubing. Nitrogen displaces air in
the tubing and prevents oxidation of the interior surfaces.
A nitrogen flow of one to three cubic feet per minute is
sufficient to displace the air. Use a pressure regulating
valve or flow meter to control the flow.
USE NITROGEN ONLY TO PURGE THE SYSTEM
WHILE SWEATING CONNECTIONS.
Failure to follow proper procedures can result in per-
sonal injury or death due to a possible formation of
an explosive mixture of R-22 and air and/or inhala-
tion of phosgene gas.
2. Ensure that the tubing surfaces to be brazed are clean,
and that the ends of the tubes have been carefully
reamed to remove any burrs.
3. Make sure the inner and outer tubes of the joint are sym-
metrical and have a close clearance, providing an easy
slip fit. If the joint is too loose, the tensile strength of the
connection will be significantly reduced. The overlap dis-
tance should be equal to the diameter of the inner tube.
4. Wrap the body of each refrigerant line component with a
wet cloth to keep it cool during brazing. Move any tube
entrance grommets away for the brazing area.
Note: Use 40 to 45% silver brazing alloy (BAg-7 or
BAg-28) on dissimilar metals. Use BCup-6 brazing
alloy on copper to copper joints.
5. If flux is used, apply it sparingly to the joint. Excessive
flux can enter the system which will contaminate the re-
frigerant system.
6. Apply heat evenly over the length and circumference of
the joint to draw the brazing material into the joint by
capillary action. Remove the brazing rod and flame from
the joint as soon as a complete fillet is formed to avoid
possible restriction in the line.
7. Visually inspect the connection after brazing to locate
any pin holes or crevices in the joint. The use of a mirror
may be required, depending on the joint location.
Leak Testing Procedure
When Leak-testing a refrigerant system, observe all safety
precautions.
Note: Never use oxygen, acetylene or compressed
air for leak testing. Always install a pressure
regulator, shutoff valves and gauges to control
pressure during leak testing.
Installation (Continued)
Summary of Contents for RAUC-IOM-15
Page 8: ...8 Figure 3 2A RAUC C80 Unit Dimensional Data Recommended Clearances...
Page 9: ...9 Figure 3 2A Continued RAUC D10 Unit Dimensional Data Recommended Clearances...
Page 10: ...10 Figure 3 2A Continued RAUC D12 Unit Dimensional Data Recommended Clearances...
Page 11: ...11 Figure 3 2B EVPB C80 Evaporator Chiller Dimensions...
Page 12: ...12 Figure 3 2B Continued EVPB D10 Evaporator Chiller Dimensions...
Page 13: ...13 Figure 3 2B Continued EVPB D12 Evaporator Chiller Dimensions...
Page 14: ...14 Figure 3 2B Continued EVPB C80 through D12 Chill Water Pipe Stubout Dimensions...
Page 35: ...35 Installation Continued Field Connection Diagram Notes for all System Control Options...
Page 57: ...57 Figure 5 5 Typical Scroll Compressor Terminal Block System Start Up Continued...
Page 67: ...67...
Page 68: ...68...
