Thermo Pride Premiere XT 16 SEER - Manual (Page 4)

4
PRECAUTIONS DURING BRAZING OF LINES
All outdoor unit and evaporator coil connections are copper-to-copper
and should be brazed with a phosphorous-copper alloy material such
as Silfos-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 pro-
vided 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
Wrap a wet rag around the service valve as shown in Figure 4 to pre-
vent heat damage. Also, protect all painted surfaces, insulation, and
plastic base during brazing. After brazing cool joint with wet rag.
Valve can be opened by removing the plunger cap and fully inserting 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 pressure
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 continue
flowing. Refer to the Tabular Data Sheet for proper liquid line sizing.
3. Go to “SECTION IV” or “SECTION V” for orifice or TXV installation
depending on application.
4. Braze the liquid line to the evaporator liquid connection. Nitrogen
should be flowing through the evaporator coil.
5. Slide the grommet away from the vapor connection at the indoor
coil. Braze the vapor line to the evaporator vapor connection. After
the connection has cooled, slide the grommet back into original
position. Refer to the Tabular Data Sheet for proper vapor line siz-
ing.
6. Protect the vapor valve with a wet rag and braze the vapor line con-
nection to the outdoor unit. The nitrogen flow should be exiting the
system from the vapor service port connection. After this connection
has cooled, remove the nitrogen source from the liquid fitting service
port.
7. Replace the Schrader core in the liquid and vapor valves.
8. Leak test all refrigerant piping connections including the service port
flare caps to be sure they are leak tight. DO NOT OVERTIGHTEN
(between 40 and 60 inch - lbs. maximum).
9. Evacuate the vapor line, evaporator and the liquid line, to 500
microns or less.
10. Replace cap on service ports. Do not remove the flare caps from the
service ports except when necessary for servicing the system.
FIGURE 3: Underground Installation
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.
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.
TO INDOOR COIL TO O UTDOOR UNIT
LIQUID LINE
CAP
PVC
CONDUIT
INSULATED
VAPOR LINE
FIGURE 4: Heat Protection
The evaporator is pressurized.
Line set and indoor coil can be pressurized to 250 psig with dry nitro-
gen and leak tested with a bubble type leak detector. Than release
the nitrogen charge.
Do not use the system refrigerant in the outdoor unit to purge or leak
test.
Do not connect manifold gauges unless trouble is suspected.
Approximately 3/4 ounce of refrigerant will be lost each time a stan-
dard manifold gauge is connected.
NOTICE
NOTICE