Installing Indoor Expansion Valve
This outdoor unit is designed for use in systems that use check expansion valve metering device. See the Lennox XP17 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 |
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PATCH PLATE |
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(UNCASED |
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| STUB |
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COIL ONLY) | LIQUID LINE |
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END | CHECK | |||||
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| ORIFICE |
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| EXPANSION | ||
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| HOUSING |
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DISTRIBUTOR |
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| VALVE | |||
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TUBES |
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| TEFLON® | |
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| RING | |
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| TEFLON® | ||
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| RING | SENSING | |
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| LINE | ||
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DISTRIBUTOR |
| EQUALIZER |
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ASSEMBLY |
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| LINE |
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| LIQUID LINE | |
ARemove the field−provided fitting that temporary reconnected the liquid line to the indoor unit’s distributor assembly.
BInstall 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.
CAttach 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.
DPlace the remaining Teflon® washer around the other end of the check expansion valve. Lightly lubricate connector threads and expose surface of the Teflon® ring with refrigerant oil.
EAttach 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.
1/2 Turn
11 12 | 1 | |
10 |
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9 |
| 43 |
8 7 | 6 | 5 |
ASSEMBLY WITH |
BRASS NUT |
SENSING BULB INSTALLATION
MALE EQUALIZER LINE | VAPOR | |
FITTING (SEE | ||
LINE | ||
EQUALIZER LINE | ||
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INSTALLATION FOR | LIQUID LINE | |
FURTHER DETAILS) | ||
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Sensing bulb insulation is required if mounted external to the coil casing. sensing bulb installation for bulb positioning.
AAttach the vapor line sensing bulb in the proper orientation as illustrated to the right using the clamp and screws provided.
NOTE
and check expansion bulb before insulating the sensing bulb once installed.
BConnect 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.
| 1/8 Turn | ||
| 11 12 | 1 | |
10 |
| 2 | |
9 |
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| 43 |
8 | 7 | 6 | 5 |
EQUALIZER LINE INSTALLATION
ARemove 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.
BRemove 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.
VAPOR LINE | ON LINES SMALLER THAN |
7/8", MOUNT SENSING | |
| BULB AT EITHER THE 3 OR |
| 9 O’CLOCK POSITION. |
| 12 |
BULB | BULB |
FLARE SEAL CAP 
OR
FLARE NUT | VAPOR LINE |
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| ON 7/8" AND LARGER LINES, |
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| MOUNT SENSING BULB AT |
COPPER FLARE |
| EITHER THE 4 OR 8 O’CLOCK |
SEAL BONNET | 12 | POSITION. NEVER MOUNT ON |
| BOTTOM OF LINE. | |
MALE BRASS EQUALIZER | BULB | BULB |
LINE FITTING |
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VAPOR LINE | NOTE OM OF LINE. |
Figure 12. Installing Indoor Expansion Valve
Page 17
XP17 SERIES