Installing Refrigerant Lines - Trane 4TTR3 Installer's Manual

Installer's Guide
BASEPAn tAB REMOVAL
2
in front of control box (access panels) & any other side
requiring service access to meet National Electrical
Code. Also, the unit location must be far enough away
from any structure to prevent excess roof run-off water
from pouring directly on the unit. Do not locate unit(s)
close to bedroom(s).
4. The top discharge area must be unrestricted for at least
five (5) feet above the unit.
5. When the outdoor unit is mounted on a roof, be sure the
roof will support the unit's weight. Properly selected
isolation is recommended to prevent sound or vibration
transmission to the building structure.
6. The maximum length of refrigerant lines from outdoor
to indoor unit should NOT exceed sixty (60) feet.
7. If outdoor unit is mounted above the air handler,
maximum lift should not exceed sixty (60) feet (suction
line). If air handler is mounted above condensing unit,
maximum lift should not exceed sixty (60) feet (liquid
line).
NOTE:
Refer to "Refrigerant Piping Software" Pub. No. 32-3312-0*
(the position of the * denotes the latest revision number).
8. Locate and install indoor coil or air handler in
accordance with instruction included with that unit.
C. InSTAllInG refrIGerAnT lIneS
CAUTION
!
If using existing refrigerant lines make certain that all
joints are brazed, not soldered.
Condensing units have provisions for braze connections.
Pressure taps are provided on the service valves of outdoor
unit for compressor suction and liquid pressures.
The indoor end of the recommended refrigerant line sets
may be straight or with a 90 degree bend, depending upon
situation requirements. This should be thoroughly checked
out before ordering refrigerant line sets.
The gas line must always be insulated.
CAUTION
!
In scroll compressor applications, dome temperatures
may be hot. Do not touch top of compressor, may cause
minor to severe burning.
The units are factory charged with the system charge
required when using fifteen (15) feet of rated connecting
line. Unit nameplate charge is with twenty-five (25) feet of
line set.
Final refrigerant charge adjustment is necessary.
Use the Subcooling Charging procedure on page 6 or in the
outdoor unit Service Facts.
1. Determine the most practical way to run the lines.
© 2009 Trane
2. Consider types of bends to be made and space limitations.
NOTE:
Large diameter tubing will be very difficult to rebend once
it has been shaped.
3. Determine the best starting point for routing the
refrigerant tubing — INSIDE OR OUTSIDE THE
STRUCTURE.
4. Provide a pull-thru hole of sufficient size to allow both
liquid and gas lines.
5. Be sure the tubing is of sufficient length.
6. Uncoil the tubing — do not kink or dent.
7. Route the tubing making all required bends and
properly secure the tubing before making connections.
8. To prevent a noise within the building structure due to
vibration transmission from the refrigerant lines, the
following precautions should be taken:
a. When the refrigerant lines have to be fastened
to floor joists or other framing in a structure, use
isolation type hangers.
b. Isolation hangers should also be used when
refrigerant lines are run in stud spaces or enclosed
ceilings.
c. Where the refrigerant lines run through a wall or
sill, they should be insulated and isolated.
d. Isolate the lines from all ductwork.
d. SERVicE VALVE OPERAtiOn
BRASS LiqUid And GAS LinE SERVicE VALVES
The Brass Liquid and Gas Line Service Valves are factory
shipped in the seated position to hold factory charge. The
pressure tap service port (when depressed) opens only to
the field brazing side of the valve when the valve is in the
seated position. The liquid line valve is not a back seating
valve (see WARNING below).
WARNING
!
extreme caution should be exercised when opening
the Liquid Line Service Valve. turn valve stem
counterclockwise only until the stem contacts the rolled
edge. (See figure 3.) no torque is required.
BRASS GAS LinE BALL SERVicE VALVE
The Brass Gas Line Ball Service Valve is shipped in the
closed position to hold the factory refrigerant charge. The
pressure tap service port (when depressed) opens only
to the field brazing side when the valve is in the closed
position. The Gas Line Ball Service Valve is full open with
a 1/4 turn. See Figure 4.
BRAzinG REFRiGERAnt LinES
1. Remove lower access cover to access service valves.
2. Before brazing, remove plugs from external copper stub
tubes. Clean internal and external surfaces of stub
tubes prior to brazing.
3. Cut and fit tubing, minimizing the use of sharp
90° bends.
4. Insulate the entire gas line and its fittings.
5. Do NOT allow uninsulated liquid line to come in direct
contact with bare gas line.
6. Precautions should be taken to avoid heat
damage to the pressure tap valve core during
brazing. It is recommended that the pressure
tap port valve core be removed and a wet rag
wrapped around the valve body.
18-AC71D1-5