Trane 2TWZ9 Installer's Manual page 2

Installer's Guide
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BASEPAN TAB REMOVAL
3. The support pad must NOT be in direct contact with
any structure. Unit must be positioned a minimum of
12" from any wall or surrounding shrubbery to insure
adequate airflow. Clearance must be provided in front of
control box (access panels) and any other side requiring
service access to meet National Electrical Code. Also, the
unit location must be far enough away from any struc-
ture 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 transmission to the
building structure.
6. The maximum length of refrigerant lines from outdoor to
indoor unit should NOT exceed eighty (80) feet.
7. If outdoor unit is mounted above the air handler, maxi-
mum lift should not exceed twenty-five (25) feet (suction
line). If air handler is mounted above condensing unit,
maximum lift should not exceed twenty-five (25) feet
(liquid line).
8. Locate and install indoor coil or air handler in accor-
dance 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.
The units are factory charged with the system charge required
when using fifteen (15) feet of connecting line. Unit nameplate
charge is the same.
Final refrigerant charge adjustment is necessary. Use
the Charging Charts in the outdoor unit Service Facts.
1. Determine the most practical way to run the lines.
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.
© 2005 American Standard Inc. All Rights Reserved
3. Determine the best starting point for routing the refriger-
ant 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 refriger-
ant 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 LINE SERVICE VALVE
The Brass Liquid Line Service Valve is 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 counterclock-
wise 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 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 Service Valve is full open with a 1/4 turn. See
Figure 4.
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LIQUID LINE SERVICE VALVE
18-BC53D1-2