550.38-N1Y
Unitary Products Group
5
®
2.
After holding charge is completely discharged, loosen
and remove the liquid line fitting from the orifice distributor
assembly. Note that the fitting has right hand threads.
3.
Remove the orifice from the distributor body using a
small diameter wire or paper clip. Orifice is not used
when the TXV assembly is installed.
4.
After orifice is removed, install the thermal expansion
valve to the orifice distributor assembly with supplied fit-
tings. Hand tighten and turn an additional 1/8 turn to
seal. Do not overtighten fittings.
5.
Reinstall the liquid line to the top of the thermal expan-
sion valve. Hand modify the liquid line to align with cas-
ing opening.
6.
Install the TXV equalizer line into the vapor line as follows:
a.
Select a location on the vapor line for insertion of the
equalizer line which will not interfere with TXV bulb
placement.
b.
Use an awl to punch through the suction tube and
insert the awl to a depth to achieve a 1/8 inch diam-
eter hole.
7.
Install TXV equalizer line in 1/8 hole previously made in
vapor line. Equalizer line can be bottomed out in vapor
line as end of equalizer line is cut on 45 degrees angle to
prevent blockage. Braze equalizer line making sure that
tube opening is not brazed closed.
All connections to be brazed 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.
Install the TXV bulb to the vapor line near the equalizer line,
using the two bulb clamps furnished with the TXV assembly.
Ensure the bulb is making maximum contact. Refer to TXV
installation instruction for view of bulb location.
a.
Bulb should be installed on a horizontal run of the
vapor line if possible. On lines under 7/8" OD the
bulb may be installed on top of the line. With 7/8"
OD and over, the bulb should be installed at the
position of about 4 or 8 o'clock.
b.
If bulb installation is made on a vertical run, the bulb
should be located at least 16 inches from any bend,
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.
The evaporator coil is under 30 psig pressure.
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.
In all cases, mount the TXV bulb after vapor line is
brazed and has had sufficient time to cool.
