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5121495-UIM-E-0716
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 (4.6 m). See Piping Application Guide (P/N 247077) for installing
tubing of longer lengths and elevation differences.
NOTICE
Using a larger than specified line size could result in oil return prob-
lems. 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" (2.5 cm) every 20 feet (6.1 m) toward the out-
door unit to facilitate proper oil return. If more than the 75 foot line
length is necessary, facilitate proper refrigerant velocity with
adjusted line diameter in accordance with the Piping Application
Guide (P/N 247077).
CAUTION
!
This system uses R-410A refrigerant which operates at higher pres-
sures than R-22. No other refrigerant may be used in this system.
Gauge sets, hoses, refrigerant containers, and recovery system
must be designed to handle R-410A. If you are unsure, consult the
equipment manufacturer.
WARNING
!
Never install a suction-line filter drier in the liquid line of an R-410A
system. Failure to follow this warning can cause a fire, injury or
death.
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 2.
6.
Use PVC piping as a conduit for all underground installations as
shown in Figure 3. 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.
FIGURE 2: Installation of Vapor Line
4
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 75 feet (22.86 m), see
Piping Application Guide (P/N 247077) for vapor and liquid line
sizing, calibration of liquid line pressure loss or gain, determination
of vapor line velocity, elevation limitations, TXV connections, sys-
tem charging, traps, etc.
TO INDOOR COI L
LI QUID LINE
PVC
CONDU IT
FIGURE 3: 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.
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.
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 4. Also, protect all
painted surfaces, insulation, and plastic base during brazing. After braz-
ing, cool joint with wet rag.
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.
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 evaporator liquid and vapor
connections at the indoor coil.
TO OUTDOOR UNIT
INSULA TED
VAPOR LINE
CAP
Johnson Controls Unitary Products
A0152-001
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