Installing Indoor Expansion Valve - Lennox XP21 Series Installation Instructions Manual

Installing Indoor Expansion Valve

This outdoor unit is designed for use in systems that use check expansion valve metering device. See the Lennox XP21
Engineering Handbook for approved check expansion valve kit match−ups and application information. 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 illustration for reference during installation of check expansion valve unit.
INDOOR EXPANSION VALVE INSTALLATION
TWO PIECE
(Uncased Coil Shown)
PATCH PLATE
(UNCASED
LIQUID LINE
COIL ONLY)
ORIFICE
HOUSING
DISTRIBUTOR
TUBES
DISTRIBUTOR
ASSEMBLY
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.
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.
FLARE SEAL CAP
STUB
CHECK
END
EXPANSION
VALVE
TEFLON
RING
®
TEFLON
SENSING
RING
EQUALIZER
LINE
LIQUID LINE
ASSEMBLY WITH
BRASS NUT
VAPOR
LINE
LIQUID LINE
FLARE NUT
COPPER FLARE
OR
SEAL BONNET
MALE BRASS EQUALIZER
LINE FITTING
VAPOR LINE
Figure 12. Installing Indoor Expansion Valve
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
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
end of the check expansion valve. Lightly lubricate
LINE
connector threads and expose surface 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.
SENSING BULB INSTALLATION
A Attach the vapor line sensing bulb in the proper
orientation as illustrated to the right using the clamp and
screws provided.
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 illustrated
below.
VAPOR LINE
BULB
VAPOR LINE
BULB
NOTE NEVER MOUNT ON BOTTOM OF LINE.
Page 17
®
rings around the
®
washer around the other
ON LINES SMALLER THAN
7/8", MOUNT
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
1/2 Turn
11 12
1
2
10
9 3
4
8
5
7
6
®
1/8 Turn
11 12
1
2
10
9 3
4
8
5
7
6
SENSING
XP21 SERIES