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506238−01 06/09
1. Attach the suction line sensing bulb in the proper orientation as illus-
trated to the right using the clamp and screws provided.
NOTE Insulating the sensing bulb once installed may be required
when the bulb location is external to the coil casing.
2. Connect the equalizer line from the CTXV to the equalizer suction port
on the suction line. Finger tighten the flare nut plus 1/8 turn (7 ft−lbs)
as illustrated below.
The CTXV unit can be installed internal or external to the indoor coil. In applications where an uncased coil is being
installed in a field−provided plenum, install the CTXV in a manner that will provide access for field servicing of the CTXV.
Refer to below illustration for reference during installation of CTXV unit.
TYPICAL CHECK THERMAL EXPANSION VALVE (CTXV) INSTALLATION PROCEDURE
D
TWO PIECE
PATCH PLATE
(UNCASED COIL
ONLY)
SUCTION
LINE
LIQUID LINE
ORIFICE
HOUSING
DISTRIBUTOR
TUBES
LIQUID
LINE
MALE EQUALIZER LINE
FITTING (SEE
EQUALIZER LINE
INSTALLATION FOR
FURTHER DETAILS)
SENSING
LINE
EQUALIZER
LINE
CTXV
TEFLON
RING
(Uncased Coil Shown)
SENSING BULB INSULATION IS
REQUIRED IF MOUNTED EXTERNAL
TO THE COIL CASING. SENSING
BULB INSTALLATION FOR BULB
POSITIONING.
STUB END
TEFLON
RING
LIQUID LINE ASSEMBLY
WITH BRASS NUT
DISTRIBUTOR
ASSEMBLY
This outdoor unit is designed for use in systems that use CTXV metering device. See the
Lennox XPG20
Engineering Handbook
for approved
CTXV kit match−ups and application information.
1. Remove the field−provided fitting that temporary reconnected the
liquid line to the indoor unit’s distributor assembly.
2. Install one of the provided Teflon rings around the stubbed end of
the CTXV and lightly lubricate the connector threads and expose
surface of the Teflon ring with refrigerant oil.
3. Attach the stubbed end of the CTXV to the liquid line orifice hous-
ing. Finger tighten and use an appropriately sized wrench to turn an
additional 1/2 turn clockwise as illustrated in the figure above, or
20 ft−lb.
4. Place the remaining Teflon washer around the other end of the
CTXV. Lightly lubricate connector threads and expose surface of
the Teflon ring with refrigerant oil.
5. Attach the liquid line assembly to the CTXV. Finger tighten and use
an appropriately sized wrench to turn an additional 1/2 turn clock-
wise as illustrated in the figure above or 20 ft−lb.
ON 7/8" AND LARGER LINES,
MOUNT SENSING BULB AT
EITHER THE 4 OR 8 O’CLOCK
POSITION. NEVER MOUNT ON
BOTTOM OF LINE.
12
ON LINES SMALLER THAN 7/8",
MOUNT SENSING BULB AT
EITHER THE 3 OR 9 O’CLOCK
POSITION.
12
BULB
SUCTION
LINE
SUCTION
LINE
NOTE
Never mount on bottom of line.
BULB
BULB
BULB
SUCTION LINE
FLARE NUT
COPPER FLARE
SEAL BONNET
MALE BRASS EQUALIZER
LINE FITTING
FLARE SEAL
CAP
OR
1
2
3
4
5
6
7
8
9
10
11 12
1/2 TURN
NOTE
− To prevent any possibility of water damage, properly insulate
all parts of the CTXV assembly that may sweat due to temperature differ-
ences between the valve and its surrounding ambient temperatures.
SENSING BULB INSTALLATION
EQUALIZER LINE INSTALLATION
1
2
3
4
5
6
7
8
9
10
11 12
1/8 TURN
1. Remove and discard either the flare seal cap or flare nut with copper
flare seal bonnet from the equalizer line port on the suction line as illus-
trated in the figure to the right.
2. Remove and discard either the flare seal cap or flare nut with copper
flare seal bonnet from the equalizer line port on the suction line as illus-
trated in the figure to the right.
