Lennox XC17, 506510-01 User Manual

INSTALLATION

E2010 Lennox Industries Inc.

Dallas, Texas, USA

NOTICE

A thermostat is not included and must be ordered
separately.

The Lennox ComfortSense® 7000 thermostat may be
used, as well as other thermostats.

In all cases, setup is critical to ensure proper system
operation.

Field wiring is illustrated in diagrams, which begin on
Page 19.

WARNING

Improper installation, adjustment, alteration, service or
maintenance can cause personal injury, loss of life, or
damage to property.

Installation and service must be performed by a licensed
professional installer (or equivalent) or a service agency.

General

This single−stage outdoor unit is designed for use with
HFC−410A refrigerant only. This unit must be installed
with an approved indoor air handler or coil. See the
Lennox XC17 Engineering Handbook for approved
indoor component matchups.

IMPORTANT

This model is designed for use in expansion valve
systems only. An indoor expansion valve approved for
use with HFC−410A refrigerant must be ordered
separately, and installed prior to operating the system.

INSTRUCTIONS

Dave Lennox Signature
Collection XC17 Units

AIR CONDITIONER

506510−01
04/10
Supersedes 506498−01

RETAIN THESE INSTRUCTIONS FOR FUTURE

REFERENCE

TABLE OF CONTENTS

General 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Shipping and Packing List 1. . . . . . . . . . . . . . . . . . . . . .

Unit Dimensions 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Model Number Identification 2. . . . . . . . . . . . . . . . . . . .

Unit Parts Arrangement 3. . . . . . . . . . . . . . . . . . . . . . . .

Operating Gauge Set and Service Valves 4. . . . . . . . .

Recovering Refrigerant from Existing System 6. . . . .

New Outdoor Unit Placement 7. . . . . . . . . . . . . . . . . . .

Removing and Installing Panels 10. . . . . . . . . . . . . . . . .

New or Replacement Line Set 11. . . . . . . . . . . . . . . . . . .

Flushing the System 14. . . . . . . . . . . . . . . . . . . . . . . . . . .

Leak Testing the System 16. . . . . . . . . . . . . . . . . . . . . . .

Evacuating the System 16. . . . . . . . . . . . . . . . . . . . . . . . .

Electrical 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Main Control Jumpers and Terminals 22. . . . . . . . . . . . .

Field Control Wiring 24. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Servicing Unit Delivered Void of Charge 26. . . . . . . . . .

Unit Start−Up 26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

System Refrigerant 26. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Operating and Temperature Pressures 30. . . . . . . . . . .

System Operations 31. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Main Control LED Alert Codes 35. . . . . . . . . . . . . . . . . .

Maintenance (Dealer and Homeowner) 42. . . . . . . . . . .

Start−Up and Performance Checklist 48. . . . . . . . . . . . .

Shipping and Packing List

Check unit for shipping damage. Consult last carrier
immediately if damage is found.

1  Assembled outdoor unit.

1  Bag assembly which includes the following:

1  Bushing (for low voltage wiring)
2  Isolation grommets for liquid and suction lines

®

Litho U.S.A.

04/10 506510−01

Page 1

*2P0410* *P506510-01*

Unit Dimensions − Inches (mm) and Parts Arrangement

39.40"
(1003)

DISCHARGE AIR

SIDE VIEW

UNIT SUPPORT

FEET

ELECTRICAL INLETS

SUCTION LINE
INLET

LIQUID
LINE
INLET

[−024] 41 (1040)

[−030 THROUGH

−060] 47 (1194)

18.60"
(470)

8.00" (203)

1 (25)

35.50"
(902)

ACCESS VIEW

Model Number Identification

Refrigerant Type

X = R−410A

Unit Type

C = Air Conditioner

Series

16−7/8

(429)

8−3/4
(222)

3−1/8

(79)

BASE WITH ELONGATED LEGS

C 17 036− −

X 2−

26−7/8

3−3/4 (95)

30−3/4

(781)

4−5/8
(117)

230

Voltage

230 = 208/230V−1ph−60hz

Nominal Cooling Capacity

024 = 2 tons
030 = 2.5 tons
036 = 3 tons
042 = 3.5 tons
048 = 4 tons
060 = 5 tons

(683)

Minor Revision Number

506510−01

Page 2

Typical Unit Parts Arrangement

CONTACTOR−1POLE (K1−1)

WIRE TIE

HIGH VOLTAGE FIELD

SLEEVE

OUTDOOR AMBIENT

TEMPERATURE

SENSOR

CONNECTIONS

GROUND LUG

MAIN CONTROL

FAN MOTOR SURGE

PROTECTION

FAN MOTOR CONTROL 

PULSE−WIDTH MODULATION (PWM)

CAPACITOR (C12)

CONTROL BOX

HIGH PRESSURE SWITCH

FIELD CONNECTION

FOR SUCTION LINE

SUCTION LINE SERVICE

SUCTION LINE SERVICE

LIQUID LINE SERVICE

LIQUID LINE SERVICE

FOR LIQUID LINE SET

VALVE PORT

VALV E

VALVE PORT

VALV E

FIELD CONNECTION

MUFFLER

HIGH DISCHARGE

LINE TEMPERATURE

SENSOR

COMPRESSOR

HARNESS

VIBRATION ISOLATOR
SLEEVE LOCATIONS (DO
NOT REMOVE)

SR1 SOUND DOME

LIQUID LINE FILTER

DRIER (SINGLE FLOW)

LOW PRESSURE SWITCH

HIGH PRESSURE SWITCH

PLUMBING, SWITCHES AND SENSOR COMPONENTS

Figure 1. Typical Parts Arrangements

Page 3

THERMOSTAT

XC17 SERIES

CAUTION

IMPORTANT

Physical contact with metal edges and corners while
applying excessive force or rapid motion can result in
personal injury. Be aware of, and use caution when
working near these areas during installation or while
servicing this equipment.

IMPORTANT

The Clean Air Act of 1990 bans the intentional venting of
refrigerant (CFCs, HCFCs AND HFCs) as of July 1,

1992. Approved methods of recovery, recycling or
reclaiming must be followed. Fines and/or incarceration
may be levied for noncompliance.

IMPORTANT

This unit must be matched with an indoor coil as
specified in Lennox’ Engineering Handbook. Coils
previously charged with HCFC−22 must be flushed.

WARNING

Electric Shock Hazard. Can cause injury
or death. Unit must be grounded in
accordance with national and local
codes.

Line voltage is present at all components
when unit is not in operation on units with
single-pole contactors. Disconnect all
remote electric power supplies before
opening access panel. Unit may have
multiple power supplies.

Operating Gauge Set and Service Valves

These instructions are intended as a general guide and do
not supersede local codes in any way. Consult authorities
who have jurisdiction before installation.

TORQUE REQUIREMENTS

When servicing or repairing heating, ventilating, and air
conditioning components, ensure the fasteners are
appropriately tightened. Table 1 lists torque values for
fasteners.

Only use Allen wrenches of sufficient hardness (50Rc −
Rockwell Harness Scale minimum). Fully insert the
wrench into the valve stem recess.

Service valve stems are factory−torqued (from 9 ft−lbs for
small valves, to 25 ft−lbs for large valves) to prevent
refrigerant loss during shipping and handling. Using an
Allen wrench rated at less than 50Rc risks rounding or
breaking off the wrench, or stripping the valve stem
recess.

See the Lennox Service and Application Notes #C−08−1
for further details and information.

IMPORTANT

To prevent stripping of the various caps used, the
appropriately sized wrench should be used and fitted
snugly over the cap before tightening.

Table 1. Torque Requirements

Parts Recommended Torque

Service valve cap 8 ft.− lb. 11 NM

Sheet metal screws 16 in.− lb. 2 NM

Machine screws #10 28 in.− lb. 3 NM

Compressor bolts 90 in.− lb. 10 NM

Gauge port seal cap 8 ft.− lb. 11 NM

USING MANIFOLD GAUGE SET

When checking the system charge, only use a manifold
gauge set that features low loss anti−blow back fittings.

Manifold gauge set used with HFC−410A refrigerant
systems must be capable of handling the higher system
operating pressures. The gauges should be rated for use
with pressures of 0 − 800 psig on the high side and a low
side of 30" vacuum to 250 psig with dampened speed to
500 psi. Gauge hoses must be rated for use at up to 800
psig of pressure with a 4000 psig burst rating.

OPERATING SERVICE VALVES

The liquid and vapor line service valves are used for
removing refrigerant, flushing, leak testing, evacuating,
checking charge and charging.

Each valve is equipped with a service port which has a
factory−installed valve stem. Figure 2 provides information
on how to access and operating both angle and ball service
valves.

506510−01

Page 4

SERVICE VALVES

VARIOUS TYPES

OPEN TO BOTH INDOOR AND

OUTDOOR UNITS

SERVICE PORT CAP

SERVICE PORT

TO INDOOR

CORE

UNIT

SERVICE PORT

(VALVE STEM
SHOWN OPEN)
INSERT HEX
WRENCH HERE

STEM CAP

SERVICE PORT CAP

SERVICE PORT

CORE

VALVE STEM

FRONT-SEATED

TO INDOOR

UNIT

TO OUTDOOR

UNIT

(FRONT−SEATED

STEM CAP

ANGLE−TYPE

SERVICE VALVE

CLOSED)

SERVICE PORT

(VALVE STEM SHOWN
CLOSED) INSERT HEX
WRENCH HERE

CLOSED TO BOTH

INDOOR AND OUTDOOR

UNITS

TO INDOOR UNIT

TO OUTDOOR UNIT

WHEN SERVICE VALVE IS CLOSED, THE SERVICE PORT IS OPEN TO THE
LINE SET AND INDOOR UNIT.

WHEN SERVICE VALVE IS OPEN, THE SERVICE PORT IS OPEN TO LINE SET,
INDOOR AND OUTDOOR UNIT.

ANGLE−TYPE SERVICE VALVE

(BACK−SEATED OPENED)

TO OPEN ROTATE STEM
COUNTERCLOCKWISE 90°.

TO CLOSE ROTATE STEM
CLOCKWISE 90°.

SERVICE PORT

SERVICE PORT CORE

SERVICE PORT CAP

To Access Service Port:

A service port cap protects the service port core from contamination and
serves as the primary leak seal.

1. Remove service port cap with an appropriately sized wrench.

2. Connect gauge set to service port.

3. When testing is completed, replace service port cap and tighten as fol­lows:

S With Torque Wrench: Finger tighten and torque cap per Table 1.
S Without Torque Wrench: Finger tighten and use an appropriately

sized wrench to turn an additional 1/6 turn clockwise.

TO OUTDOOR UNIT

12

11

10

9

8

7

6

1/6 TURN

1

2

3

4

5

Operating Angle Type Service Valve:

1. Remove stem cap with an appropriately sized wrench.

2. Use a service wrench with a hex−head extension (3/16" for liquid line valve sizes and 5/16" for vapor line valve
sizes) to back the stem out counterclockwise as far as it will go.

BALL (SHOWN CLOSED)

BALL−TYPE SERVICE

VAL VE

VALVE STEM

STEM CAP

Operating Ball Type Service Valve:

1. Remove stem cap with an appropriately sized wrench.

2. Use an appropriately sized wrenched to open. To open valve, rotate stem counterclockwise 90°. To close rotate stem clockwise 90°.

Reinstall Stem Cap:

Stem cap protects the valve stem from damage and serves as the primary seal. Replace the stem cap and
tighten as follows:

S With Torque Wrench: Finger tighten and then torque cap per Table 1.
S Without Torque Wrench: Finger tighten and use an appropriately sized wrench to turn

an additional 1/12 turn clockwise.

NOTE  A label with specific torque requirements may be affixed to the stem cap. If the label is present, use the specified torque.

10

9

8

11

1/6 TURN

12

1

2

3

4

5

7

6

Figure 2. Angle and Ball Service Valves

Page 5

XC17 SERIES

Recovering Refrigerant from Existing System

RECOVERING

REFRIGERANT FROM SYSTEM

DISCONNECT POWER

Disconnect all power to the existing outdoor unit at the disconnect

1

switch or main fuse box/breaker panel.

MAIN FUSE BOX/BREAKER PANEL

SERVICE

DISCONNECT

SWITCH

RECOVERING REFRIGERANT

Remove existing HCFC−22 refrigerant using one of the following procedures:

3

IMPORTANT  Some system configurations may contain higher than normal refrigerant charge due to either large internal coil volumes,

and/or long line sets.

CONNECT MANIFOLD GAUGE SET

Connect a gauge set, clean recovery cylinder and a recovery

2

machine to the service ports of the existing unit. Use the
instructions provided with the recovery machine to make the
connections.

MANIFOLD GAUGES

RECOVERY MACHINE

LOW

CLEAN RECOVERY
CYLINDER

OUTDOOR UNIT

HIGH

METHOD 1:

Us this method if the existing outdoor unit is not equipped with shut−off valves, or if the unit is not operational and you plan to use the existing
HCFC−22 to flush the system.

Remove all HCFC−22 refrigerant from the existing system. Check gauges after shutdown to confirm that the entire system is completely void of
refrigerant.

METHOD 2:

Use this method if the existing outdoor unit is equipped with manual shut−off valves, and you plan to use new HCFC−22 refrigerant to flush the
system.

The following devices could prevent full system charge recovery into the outdoor unit:

S Outdoor unit’s high or low−pressure switches (if applicable) when tripped can cycle the compressor OFF.
S Compressor can stop pumping due to tripped internal pressure relief valve.
S Compressor has internal vacuum protection that is designed to unload the scrolls (compressor stops pumping) when the pressure ratio meets

a certain value or when the suction pressure is as high as 20 psig. (Compressor suction pressures should never be allowed to go into a vacuum.
Prolonged operation at low suction pressures will result in overheating of the scrolls and permanent damage to the scroll tips, drive bearings and

internal seals.)
Once the compressor can not pump down to a lower pressure due to one of the above system conditions, shut off the vapor valve. Turn OFF the
main power to unit and use a recovery machine to recover any refrigerant left in the indoor coil and line set.

Perform the following task:

A Start the existing HCFC−22 system in the cooling mode and close the liquid line valve.
B Use the compressor to pump as much of the existing HCFC−22 refrigerant into the outdoor unit until the outdoor system is full. Turn the outdoor unit

main power OFF and use a recovery machine to remove the remaining refrigerant from the system.

NOTE  It may be necessary to bypass the low pressure switches (if equipped) to ensure complete refrigerant evacuation.

C When the low side system pressures reach 0 psig, close the vapor line valve.
D Check gauges after shutdown to confirm that the valves are not allowing refrigerant to flow back into the low side of the system.

506510−01

Page 6

CLEARANCE ON ALL SIDES  INCHES (MILLIMETERS)

MINIMUM CLEARANCE

ABOVE UNIT

6 (152)

12 (305)

36 (914)

ACCESS PANEL

CONTROL PANEL

ACCESS

LOCATION

30 (762)

LINE SET
CONNECTIONS

MINIMUM CLEARANCE BETWEEN

TWO UNITS

24 (610)

New Outdoor Unit Placement

NOTES:

S Clearance to one of the other three

sides must be 36 inches (914mm).

S Clearance to one of the remaining

two sides may be 12 inches
(305mm) and the final side may be
6 inches (152mm).

ACCESS PANEL

LINE SET

CONNECTIONS

Figure 3. Installation Clearances

property, not from the installation property. Install the
unit as far as possible from the property line.

48 (1219)

REAR VIEW OF UNIT

CAUTION

In order to avoid injury, take proper precaution when
lifting heavy objects.

See Unit Dimensions on page 3 for sizing mounting slab,
platforms or supports. Refer to Figure 3 for mandatory
installation clearance requirements.

POSITIONING CONSIDERATIONS

Consider the following when positioning the unit:

S Some localities are adopting sound ordinances based

on the unit’s sound level registered from the adjacent

S When possible, do not install the unit directly outside

a window. Glass has a very high level of sound
transmission. For proper placement of unit in relation
to a window see the provided illustration in Figure 4,
Detail A.

PLACING UNIT ON SLAB

When installing unit at grade level, the top of the slab
should be high enough above grade so that water from
higher ground will not collect around the unit. The slab
should have a slope tolerance as described in Figure 4,
Detail B.

NOTE  If necessary for stability, anchor unit to slab as
described in Figure 4, Detail D.

Page 7

XC17 SERIES

ELEVATING THE UNIT

Units are outfitted with elongated support feet as illustrated
in Figure 4, Detail C.

If additional elevation is necessary, raise the unit by
extending the height of the unit support feet. This may be
achieved by using a 2 inch (50.8mm) Schedule 40 female
threaded adapter.

The specified coupling will fit snuggly into the recessed
portion of the feet. Use additional 2 inch (50.8mm)
Schedule 40 male threaded adaptors which can be
threaded into the female threaded adaptors to make
additional adjustments to the level of the unit.

NOTE  Keep the height of extenders short enough to
ensure a sturdy installation. If it is necessary to extend
further, consider a different type of field−fabricated
framework that is sturdy enough for greater heights.

STABILIZING UNIT ON UNEVEN SURFACES

IMPORTANT

Unit Stabilizer Bracket Use (field−provided):

Always use stabilizers when unit is raised above the
factory height. (Elevated units could become unstable in
gusty wind conditions).

Stabilizers may be used on factory height units when
mounted on unstable an uneven surface.

With unit positioned at installation site, perform the
following:

1. Remove two side louvered panels to expose the unit
base.

2. Install the brackets as illustrated in Figure 4, Detail D
using conventional practices.

3. Replace the panels after installation is complete.

ROOF MOUNTING

Install the unit a minimum of 6 inches (152 mm) above the
roof surface to avoid ice build−up around the unit. Locate
the unit above a load bearing wall or area of the roof that
can adequately support the unit. Consult local codes for
rooftop applications.

If unit coil cannot be mounted away from prevailing winter
winds, a wind barrier should be constructed. Size barrier at
least the same height and width as outdoor unit. Mount
barrier 24 inches (610 mm) from the sides of the unit in the
direction of prevailing winds.

NOTICE

Roof Damage!
This system contains both refrigerant and oil. Some

rubber roofing material may absorb oil and cause the
rubber to swell when it comes into contact with oil. The
rubber will then bubble and could cause leaks. Protect
the roof surface to avoid exposure to refrigerant and oil
during service and installation. Failure to follow this
notice could result in damage to roof surface.

506510−01

Page 8

DETAIL A

INSTALL UNIT AWAY FROM WINDOWS

DETAIL B

INSTALL UNIT LEVEL OR, IF ON A SLOPE, MAINTAIN SLOPE TOLERANCE
OF 2 DEGREES (OR 2 INCHES PER 5 FEET [50 MM PER 1.5 M]) AWAY
FROM BUILDING STRUCTURE.

BUILDING

STRUCTURE

TWO 90° ELBOWS INSTALLED IN LINE SET WILL

REDUCE LINE SET VIBRATION.

Outside Unit Placement

DETAIL C

BASE

GROUND LEVEL

Slab Mounting at Ground Level

DETAIL D

Slab Side Mounting

#10 1/2" LONG SELF−DRILLING

SHEET METAL SCREWS

STABILIZING BRACKET (18 GAUGE

METAL  2" WIDTH; HEIGHT AS

#10 1−1/4" LONG HEX HD SCREW

CONCRETE SLAB  USE TWO PLASTIC
ANCHORS (HOLE DRILL 1/4")

WOOD OR PLASTIC SLAB  NO PLASTIC ANCHOR
(HOLE DRILL 1/8")

REQUIRED)

AND FLAT WASHER

MOUNTING
SLAB

COIL

BASE PAN

CORNER POST

LEG DETAIL

2" (50.8MM) SCH 40

FEMALE THREADED

Use additional 2" SCH 40 male threaded adapters
which can be threaded into the female threaded
adapters to make additional adjustments to the level
of the unit.

ADAPTER

2" (50.8MM) SCH 40

MALE THREADED

ADAPTER

Elevated Slab Mounting using Feet

Extenders

Figure 4. Placement, Slab Mounting and Stabilizing Unit

MINIMUM ONE

Deck Top Mounting

STABILIZING BRACKET (18 GAUGE METAL
 2" (50.8MM) WIDTH; HEIGHT AS
REQUIRED); BEND TO FORM RIGHT ANGLE

SAME FASTENERS AS
SLAB SIDE MOUNTING.

ONE BRACKET PER SIDE (MIN.); FOR EXTRA STABILITY, TWO
BRACKETS PER SIDE, 2" (50.8MM) FROM EACH CORNER.

PER SIDE

FOR EXTRA

STABILITY

Stabilizing Unit on Uneven Surfaces

IMPORTANT  To help stabilize an outdoor unit, some installations may require strap-

ping the unit to the pad using brackets and anchors commonly available in the market­place.

Page 9

XC17 SERIES

Removing and Installing Panels

ACCESS PANEL REMOVAL

Removal and reinstallation of the access

PANELS

ACCESS AND LOUVERED

WARNING

To prevent personal injury, or damage to panels, unit or structure, be sure to observe
the following:

While installing or servicing this unit, carefully stow all removed panels out of the
way, so that the panels will not cause injury to personnel, nor cause damage to ob­jects or structures nearby, nor will the panels be subjected to damage (e.g., being
bent or scratched).

While handling or stowing the panels, consider any weather conditions, especially
windy conditions, that may cause panels to be blown around and battered.

panel is as illustrated.

Detail A

REMOVE 4 SCREWS TO
REMOVE PANEL FOR
ACCESSING COMPRESSOR
AND CONTROLS.

POSITION PANEL WITH HOLES
ALIGNED; INSTALL SCREWS
AND TIGHTEN.

IMPORTANT  Do not allow panels to hang on unit by top tab. Tab is for align­ment and not designed to support weight of panel.

PANEL SHOWN SLIGHTLY ROTATED TO ALLOW TOP TAB TO EXIT (OR ENTER) TOP SLOT
FOR REMOVING (OR INSTALLING) PANEL.

LOUVERED PANEL REMOVAL

Remove the louvered panels as follows:

1. Remove two screws, allowing the panel to swing open slightly.

2. Hold the panel firmly throughout this procedure. Rotate bottom corner of panel

away from hinged corner post until lower three tabs clear the slots as illustrated in

Detail B.

3. Move panel down until lip of upper tab clears the top slot in corner post as illustrated

in Detail A.

LOUVERED PANEL INSTALLATION

Position the panel almost parallel with the unit as illustrated in Detail D with the screw
side as close to the unit as possible. Then, in a continuous motion:

1. Slightly rotate and guide the lip of top tab inward as illustrated in Detail A and C;

then upward into the top slot of the hinge corner post.

2. Rotate panel to vertical to fully engage all tabs.

3. Holding the panel’s hinged side firmly in place, close the right−hand side of the pan­el, aligning the screw holes.

4. When panel is correctly positioned and aligned, insert the screws and tighten.

Detail C

MAINTAIN MINIMUM PANEL ANGLE (AS CLOSE TO PARALLEL
WITH THE UNIT AS POSSIBLE) WHILE INSTALLING PANEL.

Detail D

ANGLE MAY BE
TOO EXTREME

LIP

SCREW

HOLES

Detail B

ROTATE IN THIS DIRECTION; THEN

DOWN TO REMOVE PANEL

HOLD DOOR FIRMLY ALONG THE
HINGED SIDE TO MAINTAIN
FULLY−ENGAGED TABS

IMPORTANT  To help stabilize an outdoor unit, some installations may require
strapping the unit to the pad using brackets and anchors commonly available in the
marketplace.

Page 10

506510−01

PREFERRED
ANGLE FOR
INSTALLATION

New or Replacement Line Set

REFRIGERANT LINE SET

This section provides information on installation or
replacement of existing line set. If new or replacement line
set is not being installed then proceed to Brazing
Connections on page 13.

IMPORTANT

NOTE  When installing refrigerant lines longer than 50
feet, see the Lennox Refrigerant Piping Design and
Fabrication Guidelines, CORP. 9351−L9, or contact
Lennox Technical Support Product Applications for
assistance.

IMPORTANT

Mineral oils are not compatible with HFC−410A. If oil

must be added, it must be a Polyol ester oil.

Lennox highly recommends changing line set when
converting the existing system from HCFC−22 to
HFC−410A. If that is not possible and the line set is the
proper size as reference in Table 2, use the procedure
outlined under Flushing the System on page 13.

If refrigerant lines are routed through a wall, then seal and
isolate the opening so vibration is not transmitted to the
building. Pay close attention to line set isolation during
installation of any HVAC system. When properly isolated
from building structures (walls, ceilings. floors), the
refrigerant lines will not create unnecessary vibration and
subsequent sounds. See Figure 5 for recommended
installation practices. Also, consider the following when
placing and installing a high−efficiency outdoor unit.

Liquid lines that meter the refrigerant, such as RFC1 liquid
lines, must not be used in this application. Existing line set
of proper size as listed in Table 2 may be reused. If system
was previously charged with HCFC−22 refrigerant, then
existing line set must be flushed (see Flushing the System
on page 14).

Field refrigerant piping consists of liquid and vapor lines
from the outdoor unit to the indoor unit coil (braze
connections). Use Lennox L15 (sweat, non−flare) series
line set, or field−fabricated refrigerant line sizes as listed in
Table 2.

Table 2. Refrigerant Line Set  Inches (mm)

Field

Connections

Model

Size

−024

−030

−036

−042

−048

−060

NOTE  Some applications may required a field provided 7/8" to
1−1/8" adapter

Liquid

Line

3/8
(10)

3/8
(10)

3/8
(10)

3/8
(10)

Vapor

Line

3/4
(19)

7/8
(22)

7/8
(22)

1−1/8.

(29)

Recommended Line Set

Liquid

Line

3/8

(10)

3/8

(10)

3/8

(10)

3/8

(10)

Vapor

Line

3/4
(19)

7/8
(22)

7/8
(22)

1−1/8

(29)

L15

Line Sets

Feet (Meters)

L15−41

15 − 50’ (5 − 15)

L15−65

15 − 50’ (5 − 15)

Field Fabricated

The compressor is charged with sufficient Polyol ester oil
for line set lengths up to 50 feet. If line set lengths longer
than 50 feet will be required, all one (1) ounce of oil for
every additional 10 feet of line set. Do not add any more
than seven (7) ounces of oil.

Recommended topping−off POE oils are Mobil EAL
ARCTIC 22 CC or ICI EMKARATEt RL32CF.

To obtain the correct information from Lennox, be sure to
communicate the following information:

S Model (XC17) and size of unit (e.g. −036).

S Line set diameters for the unit being installed as listed

in Table 2 and total length of installation.

S Number of elbows vertical rise or drop in the piping.

WARNING

Danger of fire. Bleeding the refrigerant
charge from only the high side may result
in the low side shell and suction tubing
being pressurized. Application of a
brazing torch while pressurized may
result in ignition of the refrigerant and oil
mixture − check the high and low
pressures before unbrazing.

WARNING

When using a high pressure gas such as
dry nitrogen to pressurize a refrigeration
or air conditioning system, use a
regulator that can control the pressure
down to 1 or 2 psig (6.9 to 13.8 kPa).

CAUTION

Brazing alloys and flux contain materials which are
hazardous to your health.

Avoid breathing vapors or fumes from brazing
operations. Perform operations only in well ventilated
areas.

Wear gloves and protective goggles or face shield to
protect against burns.

Wash hands with soap and water after handling brazing
alloys and flux.

Page 11

XC17 SERIES

LINE SET

INSTALLATION

Line Set Isolation  The following illustrations are

examples of proper refrigerant line set isolation:

REFRIGERANT LINE SET  TRANSITION

FROM VERTICAL TO HORIZONTAL

ANCHORED HEAVY NYLON
WIRE TIE OR AUTOMOTIVE

MUFFLER-TYPE HANGER

AUTOMOTIVE

MUFFLER-TYPE HANGER

IMPORTANT  Refrigerant lines must not contact structure.

REFRIGERANT LINE SET  INSTALLING

VERTICAL RUNS (NEW CONSTRUCTION SHOWN)

NOTE  Insulate liquid line when it is routed through areas where the
surrounding ambient temperature could become higher than the
temperature of the liquid line or when pressure drop is equal to or greater
than 20 psig.

IMPORTANT  Refrigerant lines must not contact wall

OUTSIDE WALL

VAPOR LINE

LIQUID LINE

WALL
STUD

STRAP LIQUID LINE TO
VAPOR LINE

LIQUID LINE

NON−CORROSIVE

METAL SLEEVE

VAPOR LINE − WRAPPED
IN ARMAFLEX

REFRIGERANT LINE SET  INSTALLING

HORIZONTAL RUNS

To hang line set from joist or rafter, use either metal strapping material
or anchored heavy nylon wire ties.

WIRE TIE (AROUND
VAPOR LINE ONLY)

8 FEET (2.43 METERS)

STRAPPING

MATERIAL (AROUND

VAPOR LINE ONLY)

TAPE OR
WIRE TIE

FLOOR JOIST OR

ROOF RAFTER

8 FEET (2.43 METERS)

NON−CORROSIVE
METAL SLEEVE

STRAP THE VAPOR LINE TO THE JOIST
OR RAFTER AT 8 FEET (2.43 METERS)
INTERVALS THEN STRAP THE LIQUID
LINE TO THE VAPOR LINE.

TAPE OR
WIRE TIE

WIRE TIE

INSIDE WALL

CAULK

LIQUID
LINE

STRAP

NON−CORROSIVE
METAL SLEEVE

WIRE TIE

WOOD BLOCK

WIRE TIE

STRAP

WOOD BLOCK

BETWEEN STUDS

SLEEVE

VAPOR LINE WRAPPED

WITH ARMAFLEX

OUTSIDE

WALL

PVC

PIPE

FIBERGLASS

INSULATION

NOTE  Similar installation practices should be used if line set is
to be installed on exterior of outside wall.

FLOOR JOIST OR

506510−01

ROOF RAFTER

WARNING  Polyol ester (POE) oils used with HFC−410A
refrigerant absorb moisture very quickly. It is very important that the

refrigerant system be kept closed as much as possible. DO NOT
remove line set caps or service valve stub caps until you are ready
to make connections.

Figure 5. Line Set Installation

Page 12

BRAZING

CONNECTIONS

CUT AND DEBUR

Cut ends of the refrigerant lines square

1

(free from nicks or dents) and debur the
ends. The pipe must remain round and do
not pinch end of the line.

ATTACHED GAUGES

A Connect gauge set low pressure side to liquid line service

3

valve.

B Connect gauge set center port to bottle of nitrogen with

regulator.

SERVICE PORT MUST BE OPEN TO ALLOW EXIT

INDOOR

UNIT

NOTE − Use silver alloy brazing rods with five or six percent minimum silver
alloy for copper−to−copper brazing, 45 percent alloy for copper−to−brass and
copper−to−steel brazing.

CAP AND CORE REMOVAL

Remove service cap and core

2

from both the vapor and liquid line
service ports.

HIGHLOW

B

ATTACH

POINT FOR NITROGEN

vapor LINE

GAUGES

VAPOR LINE

SERVICE

VALV E

OUTDOOR

UNIT

USE REGULATOR TO FLOW

NITROGEN AT 1 TO 2 PSIG.

WRAP SERVICE VALVE

To protect components during

4

brazing, wrap a wet cloth around
the liquid line service valve body
and copper tube stub and use
another wet cloth underneath the
valve body to protect the base
paint.

BRAZE LINE SET

Braze the liquid line to the liquid line

6

service valve. Turn off nitrogen flow.

POINT FLAME AWAY FROM

SERVICE VALVE

LIQUID LINE

LIQUID LINE SERVICE

5

NOTE  The fixed orifice or check
expansion valve metering device at the
indoor unit will allow low pressure
nitrogen to flow through the system.

VALV E

FLOW NITROGEN

Flow regulated nitrogen (at 1 to 2 psig) through the refrigeration
gauge set into the valve stem port connection on the liquid line service
valve and out of the valve stem port connection on the vapor service
valve.

INSTALL SERVICE PORT CAPS ONLY

After all connections have been brazed, disconnect manifold gauge

7

set from service ports, cool down piping with wet rag and remove all
wrappings. Do not reinstall cores until after evacuation procedure.
Reinstall service port caps if desired to close off refrigerant ports.

A

LOW

NITROGEN

HIGH

USE REGULATOR TO

FLOW NITROGEN AT 1

TO 2 PSIG.

NITROGEN

WARNING  Allow braze joint to cool before removing the wet
rag from the service valve. (TEMPERATURES ABOVE 250ºF
CAN DAMAGE VALVE SEALS

IMPORTANT  Connect gauge set low pressure side to vapor
line service valve and repeat procedure starting at paragraph 4
for brazing the liquid line to service port valve.

Page 13

SERVICE PORT

SERVICE PORT CORE

SERVICE PORT CAP

XC17 SERIES

Flushing the System

FLUSHING

LINE SET AND INDOOR COIL (1 OF 2)

TYPICAL FIXED ORIFICE REMOVAL PROCEDURE

(Uncased Coil Shown)

1

DISTRIBUTOR TUBES

LIQUID LINE ORIFICE HOUSING

TEFLON RING

FIXED ORIFICE

TWO PIECE PATCH PLATE

(UNCASED COIL ONLY)

DISTRIBUTOR

TUBES

TYPICAL CHECK EXPANSION VALVE

REMOVAL PROCEDURE

(Uncased Coil Shown)

ORIFICE

HOUSING

STUB END

TEFLON
RING

CHECK

EXPANSION

VALV E

TEFLON

RING

LIQUID LINE

SENSING

LINE

BRASS NUT

DISTRIBUTOR

ASSEMBLY

A On fully cased coils, remove the coil access and plumbing panels.
B Remove any shipping clamps holding the liquid line and distributor

assembly.

C Using two wrenches, disconnect liquid line from liquid line orifice

housing. Take care not to twist or damage distributor tubes during
this process.

D Remove and discard fixed orifice, valve stem assembly if present

and Teflon washer as illustrated above.

E Use a field−provided fitting to temporary reconnect the liquid line to

the indoor unit’s liquid line orifice housing.

REMOVE AND DISCARD

WHITE TEFLON SEAL (IF

PRESENT)

LIQUID LINE ASSEMBLY

(INCLUDES STRAINER)

CONNECT GAUGES AND EQUIPMENT FOR
FLUSHING PROCEDURE

2

VAPOR LINE

SERVICE VALVE

EXISTING

INDOOR unit

INVERTED HCFC−22
CYLINDER CONTAINS
CLEAN HCFC−22 TO BE
USED FOR FLUSHING.

A

1

NEW

OUTDOOR

UNIT

LOW

OPENED

GAUGE

MANIFOLD

CLOSED

HIGH

B

LIQUID LINE SERVICE

RECOVERY

CYLINDER

A Inverted HCFC−22 cylinder with clean refrigerant to the vapor service

B HCFC−22 gauge set (low side) to the liquid line valve.
C HCFC−22 gauge set center port to inlet on the recovery machine with

D Connect recovery tank to recovery machines per machine

VALV E

VAPOR

LIQUID

C

D

valve.

an empty recovery tank to the gauge set.

instructions.

TANK
RETURN

INLET

DISCHARGE

RECOVERY MACHINE

OR

A On fully cased coils, remove the coil access and plumbing panels.
B Remove any shipping clamps holding the liquid line and distributor as-

C Disconnect the equalizer line from the check expansion valve equaliz-

D Remove the vapor line sensing bulb.
E Disconnect the liquid line from the check expansion valve at the liquid

F Disconnect the check expansion valve from the liquid line orifice hous-

G Remove and discard check expansion valve and the two Teflon rings.
H Use a field−provided fitting to temporary reconnect the liquid line to the

DISTRIBUTOR

ASSEMBLY

MALE EQUALIZER

LINE FITTING

SENSING BULB

sembly.

er line fitting on the vapor line.

line assembly.

ing. Take care not to twist or damage distributor tubes during this pro­cess.

indoor unit’s liquid line orifice housing.

CAUTION  This procedure should not be performed on sys­tems which contain contaminants (Example compressor burn
out.

EQUALIZER
LINE

ASSEMBLY WITH

VAPOR

LINE

LIQUID LINE

BRASS NUT

LIQUID

FLUSHING LINE SET

The line set and indoor unit coil must be flushed with at least the

3

same amount of clean refrigerant that previously charged the sys­tem. Check the charge in the flushing cylinder before proceeding.

B

A Set the recovery machine for liquid recovery and start the recov-

ery machine. Open the gauge set valves to allow the recovery
machine to pull a vacuum on the existing system line set and in­door unit coil.

B Invert the cylinder of clean HCFC−22 and open its valve to allow

liquid refrigerant to flow into the system through the vapor line
valve. Allow the refrigerant to pass from the cylinder and through
the line set and the indoor unit coil before it enters the recovery
machine.

C After all of the liquid refrigerant has been recovered, switch the

recovery machine to vapor recovery so that all of the HCFC−22
vapor is recovered. Allow the recovery machine to pull down to 0
the system.

D Close the valve on the inverted HCFC−22 drum and the gauge

set valves. Pump the remaining refrigerant out of the recovery
machine and turn the machine off.

LINE

506510−01

Page 14

FLUSHING LINE SET AND INDOOR COIL (2 OF 2)

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 XC17 Engineering Handbook

4

for approved check expansion valve kit match−ups and application information.

The check expansion valve unit can be installed internal or

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.

(Uncased Coil Shown)

LIQUID LINE

ORIFICE

HOUSING

STUB

END

TEFLON
RING

EQUALIZER
LINE

CHECK

EXPANSION

VALV E

LIQUID LINE

ASSEMBLY WITH

BRASS NUT

VAPOR

LINE

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.

TEFLON

RING

A Remove the field−provided fitting that temporary reconnected the liquid

line to the indoor unit’s distributor assembly.

SENSING

LINE

LIQUID LINE

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 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.

VAPOR LINE

BULB

12

9

ON LINES SMALLER THAN 7/8",
MOUNT SENSING BULB AT
EITHER THE 3 OR 9 O’CLOCK
POSITION.

BULB

10

8

11

12

7

6

1/2 TURN

1

2

3

4

5

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.

9

10

8

11

12

7

6

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.

1

5

1/8 TURN

2

3

4

VAPOR LINE

FLARE SEAL CAP

ON 7/8" AND LARGER LINES,
MOUNT SENSING BULB AT
EITHER THE 4 OR 8 O’CLOCK

12

BULB

NOTE  NEVER MOUNT ON BOTTOM OF LINE.

OR

POSITION. NEVER MOUNT ON
BOTTOM OF LINE.

BULB

FLARE NUT

COPPER FLARE
SEAL BONNET

MALE BRASS EQUALIZER
LINE FITTING

VAPOR LINE

Page 15

XC17 SERIES