Armstrong Air Conditioning 4HP13, Installation & Start-Up Instructions

Page: 4 / 17

506318-01 Page 4 of 17 Issue 0946
Installation of Line Sets
DO NOT fasten liquid or suction lines in direct contact
with the floor or ceiling joist. Use an insulated or suspension
type of hanger. Keep both lines separate, and always
insulate the suction line. Long liquid line runs (30 feet or
more) in an attic will require insulation. Route refrigeration
line sets to minimize length.
DO NOT let refrigerant lines come in direct contact with
foundation. When running refrigerant lines through the
foundation or wall, openings should allow for a sound and
vibration absorbing material to be placed or installed
between tubing and foundation. Any gap between
foundation or wall and refrigerant lines should be filled with
a vibration damping material.
CAUTION
If ANY refrigerant tubing is buried, provide a 6 inch vertical
rise at service valve. Refrigerant tubing lengths up to 36
inches may be buried without further special
consideration. For lengths above 36 inches, consult your
local distributor.
Before making braze connections, be sure all joints are
clean. Before heat is applied for brazing, dry nitrogen should
be flowing through the tubing to prevent oxidation and scale
formation on the inside of the tubing.
The following is the recommended method for making
braze connections at the refrigerant line connections:
1. Debur and clean refrigerant tube end with emery
cloth or steel brush.
2. Insert tubing into swage fitting connection.
3. Wrap wet rags over valves to protect from heat.
4. Allow dry nitrogen to flow through refrigerant lines.
5. Braze joint, using a suitable brazing alloy for copper
to copper joints.
6. Quench the joint and tubing with water using a wet
rag. Leave rag on fitting body and re-wet with water
to help cool area.
Leak Check
Refrigeration lines and indoor coil must be checked for
leaks after brazing and before evacuation. The
recommended procedure is to apply a trace amount of vapor
refrigerant (approximately two ounces or 3 psig) into the
line set and indoor coil, then pressurize with 150 psig of dry
nitrogen. Use a refrigerant leak detector to check all joints.
The system may also be checked for leaks using a halide
torch or pressure and soapy solution. After completion of
leak check, relieve all pressure from system before
evacuation.
Evacuating And Charging Instructions
NOTE: Intentional release of CFC or HCFC refrigerant
to the atmosphere violates Federal Law. It may also
violate State and Local Codes. Check all Federal, State
and Local Codes before proceeding.
These outdoor units are pre-charged at the factory with
adequate refrigerant to handle 15 feet of refrigerant tubing.
NOTE: DO NOT use any portion of the charge for purging
or leak testing. It is mandatory that a thorough evacuation
of the refrigeration lines and indoor coil be performed.
The liquid line and suction line service valves have been
closed after final testing at the factory. DO NOT disturb
these valves until the lines have been leak checked and
evacuated or the charge in the unit may be lost.
1. Connect the vacuum pump to the center hose of the
manifold gauge set, the low-pressure manifold gauge to the
vapor service valve and the high pressure manifold gauge
to the liquid service valve.
NOTE: Unnecessary switching of hoses can be avoided
and complete evacuation of all lines can be achieved by
also connecting a branch hose from the manifold gauge
center port to a cylinder of the proper refrigerant. Provide a
separate shut-off valve to vacuum pump to avoid
contaminating vacuum pump oil with refrigerant.
2. The valves should be kept in the “front seated”
(closed) position. This will allow evacuation of the
refrigeration lines and the indoor coil, without disturbing the
factory charge in the outdoor unit.
3. Follow the vacuum pump manufacturer ’s
instructions. Allow the pump to operate until the system
has been evacuated down to 300 microns. Allow the pump
to continue running for an additional 15 minutes. Turn OFF
the pump and leave the connections secured to the two (2)
service valves. After 5 minutes, if the system fails to hold
500 microns or less, check all connections for tight fit and
repeat the evacuation procedure.
4. Isolate the vacuum pump from the system by
closing the shutoff valves on the gauge-set. Disconnect
the vacuum pump.
Opening Service Valves
After evacuation of the connecting lines, remove the
service valve cap and fully insert the hex wrench into the
stem. A back-up wrench is required on the valve body to
open the valve stem. Back-out counterclockwise until the
valve stem just touches the coined edge.
Wrench sizes:
3/8 service valve: 3/16" Hex wrench
3/4 service valve: 5/16" Hex wrench
7/8 service valve: 5/16" Hex wrench