5390862-UIM-A-0318
Johnson Controls Unitary Products
5
4. Tape and suspend the refrigerant lines as shown. DO NOT allow
tube metal-to-metal contact. See Figure 3.
5. Use PVC piping as a conduit for all underground installations as
shown in Figure 4. Buried lines should be kept as short as possible
to minimize the build up of liquid refrigerant in the vapor line during
long periods of shutdown.
6. Pack fiberglass insulation and a sealing material such as perma-
gum around refrigerant lines where they penetrate a wall to reduce
vibration and to retain some flexibility.
PRECAUTIONS DURING BRAZING OF LINES
All outdoor unit and indoor coil connections are copper-to-copper and
should be brazed with a phosphorous-copper alloy material such as Sil-
fos-5 or equivalent. DO NOT use soft solder. The outdoor units have
reusable service valves on both the liquid and vapor connections. The
total system refrigerant charge is retained within the outdoor unit during
shipping and installation. The reusable service valves are provided to
evacuate and charge per this instruction.
Serious service problems can be avoided by taking adequate precau-
tions to assure an internally clean and dry system.
PRECAUTIONS DURING BRAZING SERVICE VALVE
Precautions should be taken to prevent heat damage to service valve
by wrapping a wet rag around it as shown in Figure 5. Also, protect all
painted surfaces, insulation, and plastic base during brazing. After braz-
ing, cool joint with wet rag.
Valve can be opened by removing the service valve cap and fully insert-
ing a hex wrench into the stem and backing out counter-clockwise until
valve stem just touches the chamfered retaining wall.
Connect the refrigerant lines using the following procedure:
1.
Remove the cap and Schrader core from both the liquid and vapor
service valve service ports at the outdoor unit. Connect low pres-
sure nitrogen to the liquid line service port.
2.
Braze the liquid line to the liquid valve at the outdoor unit. Be sure
to wrap the valve body with a wet rag. Allow the nitrogen to con-
tinue flowing.
3.
Carefully remove the plugs from the indoor coil liquid and vapor
connections at the indoor coil.
4.
Braze the liquid line to the indoor coil liquid connection. Nitrogen
should be flowing through the indoor coil.
5.
Slide the grommet away from the vapor connection at the indoor
coil. Braze the vapor line to the indoor coil vapor connection. After
the connection has cooled, slide the grommet back into original
position.
6.
Protect the vapor valve with a wet rag and braze the vapor line
connection to the outdoor unit. The nitrogen flow should be exiting
the system from the vapor service port connection. After this con-
nection has cooled, remove the nitrogen source from the liquid fit-
ting service port.
7.
Replace the Schrader core in the liquid and vapor valves.
8.
Go to SECTION IV for TXV installation.
9.
Leak test all refrigerant piping connections including the service
port flare caps to be sure they are leak tight. DO NOT OVER-
TIGHTEN (between 40 and 60 inch - lbs. maximum).
FIGURE 3:
Insulation of Vapor Line
FIGURE 4:
Underground Installation
CAUTION
Dry nitrogen should always be supplied through the tubing while it is
being brazed, because the temperature required is high enough to
cause oxidation of the copper unless an inert atmosphere is provided.
The flow of dry nitrogen should continue until the joint has cooled.
Always use a pressure regulator and safety valve to insure that only
low pressure dry nitrogen is introduced into the tubing. Only a small
flow is necessary to displace air and prevent oxidation.
Liquid
Line
Incorrect
Correct
Tape
Sheet Metal Hanger
Insulated Vapor Line
A0151-001
TO INDOOR COIL
TO OUTDOOR UNIT
LIQUID LINE
CAP
PVC
CONDUIT
INSULATED
VAPOR LINE
A0152-001
!
WARNING
This is not a backseating valve. The service access port has a valve
core. Opening or closing valve does not close service access port.
If the valve stem is backed out past the chamfered retaining wall, the
O-ring can be damaged causing leakage or system pressure could
force the valve stem out of the valve body possibly causing personal
injury.
FIGURE 5:
Heat Protection
CAUTION
Do not install any coil in a furnace which is to be operated during the
heating season without attaching the refrigerant lines to the coil. The
coil is under pressure which must be released to prevent excessive
pressure build-up and possible coil damage.
!
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