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Installer's Guide
2
BASEPAN
TAB REMOVAL
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 name-
plate charge is with twenty-five (25) feet of line set.
Final refrigerant charge adjustment is necessary. Use
the Subcooling Charging procedure 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.
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 pres-
sure tap service port (when depressed) opens only to the field
brazing side of the valve when the valve is in the seated posi-
tion. 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 Figures 3
and 5) No torque is required. Failure to follow this warning will
result in abrupt release of system charge and may result in
personal injury and/or property damage.
© 2007 American Standard Inc. All Rights Reserved
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.
NOTE:
Use care to make sure that no moisture enters pressure tap
port, while wet rag is being used.
NOTE:
Precautions should be taken to avoid heat damage to
basepan during brazing. It is recommended to keep the flame
directly off of the basepan.
7. Use a Dry Nitrogen Purge and Brazing Alloy without flux
when brazing the field line to the copper factory connec-
tion. Flow dry nitrogen into either valve pressure tap port,
thru the tubing and out the other port while brazing.
8. Braze using accepted good brazing techniques.
LEAK CHECK
IMPORTANT:
Replace pressure tap port valve core before attaching hoses for
evacuation.
After the brazing operation of refrigerant lines to both the
outdoor and indoor unit is completed, the field brazed connec-
tions must be checked for leaks. Pressurize through the service
valve ports, the indoor unit and field refrigerant lines with dry
nitrogen to 350-400 psi. Use soap bubbles or other leak-
checking methods to see that all field joints are leak-free! If not,
release pressure; then repair!
3
LIQUID LINE SERVICE VALVE
18-AC53D1-5
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