Lennox XC21 Installation Instructions Manual page 15

FLUSHING LINE SET AND INDOOR COIL (2 OF 2)
4
TYPICAL CHECK EXPANSION VALVE INSTALLATION PROCEDURE
This outdoor unit is designed for use in systems that use check expansion valve metering device. See the Lennox XC21 Engineering Handbook
for approved check expansion valve kit match−ups and application information.
TWO PIECE
(Uncased Coil Shown)
PATCH PLATE
(UNCASED
LIQUID LINE
COIL ONLY)
ORIFICE
HOUSING
DISTRIBUTOR
TUBES
EQUALIZER
DISTRIBUTOR
ASSEMBLY LINE
MALE EQUALIZER LINE
FITTING (SEE
EQUALIZER LINE
INSTALLATION FOR
FURTHER DETAILS)
SENSING BULB INSULATION IS REQUIRED
IF MOUNTED EXTERNAL TO THE COIL
CASING. SENSING BULB INSTALLATION
FOR BULB POSITIONING.
SENSING BULB INSTALLATION
A Attach the vapor line sensing bulb in the proper orientation
as illustrated to the right using the clamp and screws pro-
vided.
NOTE Confirm proper thermal contact between vapor line
and check expansion bulb before insulating the sensing bulb
once installed.
B Connect the equalizer line from the
check expansion valve to the
equalizer vapor port on the vapor
line. Finger tighten the flare nut
plus 1/8 turn (7 ft−lbs) as illus-
trated below.
EQUALIZER LINE INSTALLATION
A Remove and discard either the flare seal cap or flare nut
with copper flare seal bonnet from the equalizer line port
on the vapor line as illustrated in the figure to the right.
B Remove and discard either the flare seal cap or flare nut
with copper flare seal bonnet from the equalizer line port on
the vapor line as illustrated in the figure to the right.
The check expansion valve 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 check
expansion valve in a manner that will provide access for field
servicing of the check expansion valve. Refer to below
STUB
illustration for reference during installation of check expansion
CHECK
END
EXPANSION valve unit.
VALVE
TEFLON
RING
TEFLON
SENSING
RING
LINE
LIQUID LINE
ASSEMBLY WITH
BRASS NUT
VAPOR
LINE
LIQUID LINE
1/8 TURN
11 12
1
2
10
9
4
8
5
7
6
A Remove the field−provided fitting that temporary reconnected the liquid
line to the indoor unit's distributor assembly.
B Install one of the provided Teflon rings around the stubbed end of the
check expansion valve and lightly lubricate the connector threads and
expose surface of the Teflon ring with refrigerant oil.
C Attach the stubbed end of the check expansion valve to the liquid line
orifice housing. 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.
D Place the remaining Teflon washer around the other end of the check
expansion valve. Lightly lubricate connector threads and expose sur-
face of the Teflon ring with refrigerant oil.
E Attach the liquid line assembly to the check expansion valve. 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.
VAPOR LINE
BULB
VAPOR LINE
BULB
NOTE
3
FLARE SEAL CAP
Page 15
11 12
10
9
8
7
ON LINES SMALLER THAN 7/8",
MOUNT SENSING BULB AT
EITHER THE 3 OR 9 O'CLOCK
POSITION.
12
BULB
ON 7/8" AND LARGER LINES,
MOUNT SENSING BULB AT
EITHER THE 4 OR 8 O'CLOCK
POSITION. NEVER MOUNT ON
12 BOTTOM OF LINE.
BULB
NEVER MOUNT ON BOTTOM OF LINE.
OR
MALE BRASS EQUALIZER
LINE FITTING
VAPOR LINE
1/2 TURN
1
2
3
4
5
6
FLARE NUT
COPPER FLARE
SEAL BONNET
XC21 SERIES