Installing New Indoor Metering Device - Lennox Merit 13HPX Series Installation Instructions Manual

Installing New Indoor Metering Device

This outdoor unit is designed for use in HFC−410A systems that use a check / expansion valve metering device (purchased
separately) at the indoor coil.
See the Lennox 13HPX Engineering Handbook for approved check / expansion valve kit match−ups. The check / expansion
valve device can be installed either 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 (see figure 11).
INDOOR EXPANSION VALVE INSTALLATION
TWO PIECE
PATCH PLATE
(UNCASED
COIL ONLY)
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
Downloaded from ManualsNet.com
(Uncased Coil Shown)
STUB
LIQUID LINE
EXPANSION
END
ORIFICE
VALVE
HOUSING
®
TEFLON
RING
EQUALIZER
LINE
LIQUID LINE
ASSEMBLY WITH
BRASS NUT
VAPOR
LINE
OR
MALE BRASS EQUALIZER
LINE FITTING
VAPOR LINE
Figure 11. Installing Indoor Check / Expansion Valve
search engine
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 expansion valve and lightly lubricate
the connector threads and expose surface of the Teflon
ring with refrigerant oil.
®
TEFLON C Attach the stubbed end of the expansion valve to the
RING
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
SENSING
end of the expansion valve. Lightly lubricate connector
LINE
threads and expose surface of the Teflon
refrigerant oil.
E Attach the liquid line assembly to the 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 expansion bulb before insulating the sensing bulb once
LIQUID LINE
installed.
B Connect the equalizer line from the 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
FLARE NUT
VAPOR LINE
COPPER FLARE
SEAL BONNET
BULB
NOTE
Page 15
®
rings around the
®
washer around the other
®
ring with
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
NEVER MOUNT 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
5
7
6
SENSING
13HPX SERIES