![American Standard 2A7B3018-1000A Скачать руководство пользователя страница 3](http://html1.mh-extra.com/html/american-standard/2a7b3018-1000a/2a7b3018-1000a_installers-manual_2926148003.webp)
Pub. No. 11-AC17D1-1
PAGE 3
INSTALLER'S GUIDE
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 recom-
mended that the pressure tap port valve core be removed
and a wet rag wrapped around the valve body.
NOTICE: Use care to make sure that no moisture enters pressure
tap port, while wet rag is being used.
NOTICE: 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 connection.
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!
CAP
1/4 TURN ONLY
COUNTERCLOCKWISE
FOR FULL OPEN
POSITION
VALVE STEM
GAS LINE CONNECTION
UNIT SIDE
OF VALVE
CAP
BODY
COOLING
CORE
PRESSURE TAP PORT
HEATING
GAS LINE BALL SERVICE VALVE
SYSTEM EVACUATION
NOTE: Since the outdoor unit has a refrigerant charge, the gas
and liquid line valves must remain closed.
1. Upon completion of leak check, evacuate the refrigerant lines
and indoor coil before opening the gas and liquid line valves.
2. Attach appropriate hoses from manifold gauge to gas and
liquid line pressure taps.
NOTE: Unnecessary switching of hoses can be avoided and
complete evacuation of all lines leading to sealed system can be
accomplished with manifold center hose and connecting branch
hose to a cylinder of HCFC-22 and vacuum pump.
3. Attach center hose of manifold gauges to vacuum pump.
4. Evacuate until the micron gauge reads no higher than
350 microns.
5. Close off valve to vacuum pump and observe the micron
gauge. If gauge pressure rises above 500 microns in one (1)
minute, then evacuation is incomplete or system has a leak.
6. If vacuum gauge does not rise above 500 microns in one (1)
minute, the evacuation should be complete.
7. With vacuum pump and micron gauge blanked off, open
valve on HCFC-22 cylinder and charge refrigerant lines and
indoor coil with vapor to tank pressure of HCFC-22 supply.
NOTE: DO NOT VENT REFRIGERANT INTO THE
ATMOSPHERE.
8. Close valve on HCFC-22 supply cylinder. Close valves on
manifold gauge set and remove refrigerant charging hoses from
liquid and gas pressure tap ports.
NOTE: A 3/16" Allen wrench is required to open liquid line
service valve. A 1/4" Open End or Adjustable wrench is required
to open gas line valve. A 3/4" Open End wrench is required to
take off the valve stem cap.
9. The liquid line shut-off valve can now be opened. Remove
shut-off valve cap. Fully insert hex wrench into the stem and
back out counterclockwise until valve stem just touches rolled
edge (approximately five [5] turns) observing WARNING state-
ment on page 2. See Figure 3.
10. Replace liquid service pressure tap port cap and valve stem
cap. These caps MUST BE REPLACED to prevent leaks.
Replace valve stem and pressure tap cap finger tight, then
tighten an additional 1/6 turn.
4
5
GAS LINE SERVICE VALVE