Precautions During Brazing Service Valve; Precautions During Line Installation; Precautions During Brazing Of Lines; Piping Connections - Johnson Controls 13 SEER Installation Manual

PIPING CONNECTIONS

The outdoor condensing unit must be connected to the indoor evapora-
tor coil using field supplied refrigerant grade (ACR) copper tubing that is
internally clean and dry. Units should be installed only with the tubing
sizes for approved system combinations as specified in tabular data
sheet. The charge given is applicable for total tubing lengths up to 15
feet. See Application Data Part Number 036-61920-000 for installing
tubing of longer lengths and elevation differences.
NOTE: Using a larger than specified line size could result in oil return
problems. Using too small a line will result in loss of capacity
and other problems caused by insufficient refrigerant flow. Slope
horizontal vapor lines at least 1" every 20 feet toward the out-
door unit to facilitate proper oil return.
OIL TRAPPING
When the outdoor unit is above the indoor coil, oil trapping is necessary.
An oil trap should be provided for every 20 ft. of rise. See Figure 2.
INDOOR
COIL
FIGURE 2: Oil Trap

PRECAUTIONS DURING LINE INSTALLATION

1. Install the lines with as few bends as possible. Care must be taken
not to damage the couplings or kink the tubing. Use clean hard
drawn copper tubing where no appreciable amount of bending
around obstruction is necessary. If soft copper must be used, care
must be taken to avoid sharp bends which may cause a restriction.
2. The lines should be installed so that they will not obstruct service
access to the coil, air handling system, or filter.
3. Care must also be taken to isolate the refrigerant lines to minimize
noise transmission from the equipment to the structure.
4. The vapor line must be insulated with a minimum of 1/2" foam rub-
ber insulation (Armaflex or equivalent). Liquid lines that will be
exposed to direct sunlight, high temperatures, or excessive humid-
ity must also be insulated.
5. Tape and suspend the refrigerant lines as shown. DO NOT allow
tube metal-to-metal contact. See Figure 3.
6. 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
7. 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.
8. For systems with total line length exceeding 50 ft., see APPLICA-
TION DATA and worksheet "General Piping Recommendations
and Refrigerant Line Length" for vapor and liquid line sizing, cali-
bration of liquid line pressure loss or gain, determination of vapor
line velocity, elevation limitations, orifice connections, system
charging, traps, etc.
Johnson Controls Unitary Products
OUTDOOR COIL
10 In.
20 Ft.
6 In.
20 Ft.
Sheet Metal Hanger
Liquid
Line
Incorrect
Correct
FIGURE 3: Installation of Vapor Line
TO INDOOR COIL
Liquid Line
PVC
Conduit
FIGURE 4: Underground Installation

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.
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 pro-
vided. 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.

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.
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.
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.
347337-UIM-A-0408
Tape
Insulated Vapor Line
TO OUTDOOR UNIT
Insulated
Vapor Line
Cap
3