Installing Refrigerant Lines - Trane 2TWR3 Installer's Manual

Installer's Guide
2
BASEPAN TAB REMOVAL
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 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 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, maxi-
mum lift should not exceed sixty (60) feet (suction line). If
air handler is mounted above condensing unit, maxi-
mum lift should not exceed sixty (60) 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.
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 the same.
Final refrigerant charge adjustment is necessary. Use
the Charging Information in the outdoor unit Service Facts
and on page 6.
1. Determine the most practical way to run the lines.
2. Consider types of bends to be made and space
limitations.
© 2005 American Standard Inc. All Rights Reserved
NOTE:
Large diameter tubing will be very difficult to rebend once it
has been shaped.
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 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 and Gas Line Service Valves. Turn valve stem
counterclockwise only until the stem contacts the rolled
edge. (See Figures 3 and 5) 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.
3
LIQUID LINE SERVICE VALVE
18-BC59D1-1