Unit installation

Maintenance
SCXF-SVX01K-EN 85
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.
When Leak-testing refrigerant systems, observe all safety
precautions
Leak test only one circuit at a time to minimize system
exposure to potentially harmful moisture in the air.
Field Piping (air cooled discharge and liquid
lines)
1. Ensure all required field installed piping pressure tests
are completed in accordance with national and/or local
codes.
2. Close liquid line angle valve.
3. Connect R-410A refrigerant cylinder to high side
c
harging port (at Remote Condenser or field supplied
discharge line access port). Add refrigerant to reach
pressure of 12 to 15 psig.
4. Disconnect refrigerant cylinder. Connect dry nitrogen
cylinder
to high side charging port and increase
pressure to 150 psig. Do not exceed high side
(discharge) unit nameplate design pressure. Do not
subject low side (suction) components to high side
pressure.
5. Check all piping joints, valves, etc. for leaks.
R
ecommend using electronic detector capable of
measuring 0.1 oz/year leak rate.
6. If a leak is located, use proper procedures to remove
the
refrigerant/nitrogen mixture, break connections
and make repairs. Retest for leaks.
7. Make sure all service valves are open.
System Repair
1. If system is water cooled with service valves, or air
cooled, high and low side may be tested independently
by closing liquid line angle valve and water cooled unit
discharge line ball valve. Otherwise leave all valves
open and DO NOT exceed low side design pressure.
2. Connect R-410A refrigerant cylinder to charging port,
add
refrigerant to reach pressure of 12 to 15 psig.
3. Disconnect refrigerant cylinder. Connect dry nitrogen
cylinder
to high side charging port and increase
pressure to 150 psig. DO NOT exceed unit nameplate
design pressures. If testing complete system, low side
design pressure is maximum.
4. Check piping and/or components as appropriate for
leaks.
5. Recommend using electronic detector capable of
measuring
0.1 oz/year leak rate.
6. If a leak is located, use proper procedures to remove
the
refrigerant/nitrogen mixture, break connections
and make repairs. Retest for leaks.
7. Make sure all service valves are open.
Brazing Procedures
Proper brazing techniques are essential when installing
refrigerant piping.The following factors should be kept in
mind when forming sweat connections.
1. When heating copper in the presence of air, copper
oxide forms.To prevent copper oxide from forming
inside the tubing during brazing, sweep an inert gas,
such as dry nitrogen, through the tubing. A nitrogen
flow of 1 to 3 cubic feet per minute is sufficient to
displace the air in the tubing and prevent oxidation of
the interior surfaces. Use a pressure regulating valve
or flow meter to control the flow.
2. Ensure that the tubing surfaces requiring brazing are
clean,
and that the tube ends are carefully reamed to
remove any burrs.
WARNING
Hazardous of Explosion!
Do not exceed unit nameplate design pressures when
leak testing system. Failure to follow these instructions
could result in an explosion causing death or serious
injury.
WARNING
R-410A Refrigerant under High Pressure!
The units described in this manual use R-410A
refrigerant. Use ONLY R-410A rated service equipment
or components with these units. For specific handling
concerns with R-410A, please contact your local Trane
representative. Failure to use R-410A rated service
equipment or components could result in equipment
exploding under R-410A high pressures which could
result in death, serious injury, or equipment damage.
WARNING
Hazard of Explosion and Deadly Gases!
Never solder, braze or weld on refrigerant lines or any
unit components that are above atmospheric pressure
or where refrigerant may be present. Always remove
refrigerant by following the guidelines established by
the EPA Federal Clean Air Act or other state or local
codes as appropriate. After refrigerant removal, use dry
nitrogen to bring system back to atmospheric pressure
before opening system for repairs. Mixtures of
refrigerants and air under pressure may become
combustible in the presence of an ignition source
leading to an explosion. Excessive heat from soldering,
brazing or welding with refrigerant vapors present can
form highly toxic gases and extremely corrosive acids.
Failure to follow all proper safe refrigerant handling
practices could result in death or serious injury.