Lennox Merit Series 13HPX Units Installation Instructions Manual page 8

STEP 2 -- REFRIGERANT PIPING -- Installing Indoor Expansion Valve
This outdoor unit is designed for use in systems that include an expansion valve metering device (purchased separately) at
the indoor coil. See the 13HPX Product Specifications bulletin (EHB) for approved expansion valve kit match ups. The
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 expansion valve in a manner that will provide access for field servicing of the
expansion valve. Refer to below illustration for reference during installation of expansion valve unit. After installation of the
indoor coil metering device, proceed to Step 5.
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
DETAILS)
Sensing bulb insulation is required if
check/expansion valve is installed external
to the coil casing. See 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 below.
B. Remove the field-provided fitting that temporarily reconnected
the liquid line to the indoor unit's distributor assembly.
FLARE SEAL CAP
INDOOR EXPANSION VALVE INSTALLATION
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
C. Install one of the provided Teflon
stubbed end of the check/expansion valve and use re­
frigerant oil to lightly lubricate the connector threads
and exposed surface of the Teflon
D. Attach the stubbed end of the check/expansion valve
to the liquid line orifice housing. Finger tighten, then use
® an appropriately sized wrench to turn an additional 1/2
turn clockwise as illustrated in the figure to the right, or
tighten to 20 ft-lb.
E. Place the remaining Teflon
end of the check expansion valve. Lightly lubricate
connector threads and expose surface of the Teflon
LINE
ring with refrigerant oil.
F. Attach the liquid line assembly to the check expansion
valve. Finger tighten, then use an appropriately sized
wrench to turn an additional 1/2 turn clockwise as illus­
trated in the figure above or tighten to 20 ft-lb.
SENSING BULB INSTALLATION
A. Attach the vapor line sensing bulb in the proper orienta­
tion as illustrated below using the clamp and screws
provided.
B. NOTE - Though it is preferred to have the sensing bulb
installed on a horizontal run of the vapor line, installation
on a vertical run of piping is acceptable if necessary.
NOTE — Confirm proper thermal contact between vapor line
and check/expansion bulb before insulating the sensing bulb.
C. Connect the equalizer line from the check/expansion
valve to the equalizer vapor port on the vapor line. Fin­
ger tighten the flare nut, then tighten an additional 1/8
turn (7 ft-lbs) as illustrated to the right.
VAPOR LINE
BULB
VAPOR LINE
BULB
NOTE — NEVER MOUNT THE SENSING BULB
FIGURE 9
Page 8
®
rings around the
®
ring.
®
washer around the other
ON LINES SMALLER THAN
7/8",
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.
THE SENSING
12
BOTTOM OF LINE.
BULB
ON BOTTOM OF LINE.
1/2 Turn
11 12
1
2
10
9 3
4
8
7 5
6
®
1/8 Turn
11 12
1
2
10
9 3
4
8
7 5
6
MOUNT SENSING
NEVER MOUNT
BULB ON