®
035-14511-000 REV B (1299)
5
Unitary Products Group
and on the tubing sides opposite the plane of the
bend. On vertical bulb installations, the bulb should
be positioned with the bulb tail at the top, so that the
bulb acts as a reservoir.
c.
Bulb should be insulated using thermal insulation
provided to protect it from the effect of the surround-
ing ambient temperature.
PIPING CONNECTIONS
The outdoor condensing unit may be connected to the indoor
evaporator coil using field supplied refrigerant grade copper
tubing that is internally clean and dry. Units should be
installed only with the tubing sizes for approved system com-
binations as specified in Tabular Data Sheet. The charge
given is applicable for total tubing lengths up to 15 feet. See
Application Data Form 690.01-AD1V 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 outdoor unit to facilitate proper
oil return.
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 apprecia-
ble 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 rubber insulation (Arm-A-Flex or equivalent). Liquid
lines that will be exposed to direct sunlight and/or high
temperatures must also be insulated.
Tape and suspend the refrigerant lines as shown. DO NOT
allow metal-to metal contact. See Figure 3.
5.
Use PVC piping as a conduit for all underground installa-
tions 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 shut-
down.
6.
Pack fiber glass insulation and a sealing material such
as permagum around refrigerant lines where they pen-
etrate a wall to reduce vibration and to retain some
flexibility.
7.
See Form 690.01-AD1V for additional piping information.
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.
FIGURE 3 :
TUBING HANGER
FIGURE 4 :
UNDERGROUND INSTALLATION
Dry nitrogen should always be supplied through the
tubing while it is being brazed, because the tempera-
ture 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 neces-
sary to displace air and prevent oxidation.
L IQ UID
L IN E
T AP E
INS U LA TE D VA P O R L
INE
C O R R EC T
INC O R R EC T
SH EET METAL HAN G ER
TO INDOOR COIL
TO OUTDOOR UNIT
LIQUID LINE
CAP
PVC
CONDUIT
INSULATED
VAPOR LINE
CAUTIO
