Lennox Elite XC16, Elite XC16-024, Elite XC16-036, Elite XC16-048, Elite XC16-060 Installation Instructions Manual

INSTALLATION

E2009 Lennox Industries Inc.

Dallas, Texas, USA

RETAIN THESE INSTRUCTIONS

FOR FUTURE REFERENCE

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.

CAUTION

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.

INSTRUCTIONS

Elite® Series XC16 Units

AIR CONDITIONER

506101−01
07/09
Supersedes 04/08

Table of Contents

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

XC16 Outdoor Unit 1. . . . . . . . . . . . . . . . . . . . . . . . . . . .

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

General Information 2. . . . . . . . . . . . . . . . . . . . . . . . . . .

Recovering Refrigerant from Existing System 2. . . . .

Removing Existing Outdoor Unit 5. . . . . . . . . . . . . . . . .

Positioning New Outdoor Unit 5. . . . . . . . . . . . . . . . . . .

Removing and Installing Panels 5. . . . . . . . . . . . . . . . .

New or Replacement Line Set 8. . . . . . . . . . . . . . . . . . .

Brazing Connections 9. . . . . . . . . . . . . . . . . . . . . . . . . . .

Removing Indoor Unit Metering Device 10. . . . . . . . . . .

Flushing System 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Installing New Indoor Unit Metering Device 12. . . . . . . .

Testing for Leaks 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Evacuating the System 12. . . . . . . . . . . . . . . . . . . . . . . . .

Servicing Units Delivered Void of Charge 14. . . . . . . . .

Electrical Connections 15. . . . . . . . . . . . . . . . . . . . . . . . .

Start−Up, Testing and Charging Procedures 15. . . . . . .

System Operation 20. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Maintenance 20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Homeowner Information 21. . . . . . . . . . . . . . . . . . . . . . . .

Checklists 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Shipping and Packing List

Litho U.S.A.

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.

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.

07/09 506101−01

*2P0709* *P506101-01*

Check the unit for shipping damage and listed times below
are intact. If damaged, or if parts are missing, immediately
contact the last shipping carrier.

S Assembled outdoor unit

XC16 Outdoor Unit

The XC16 Air Conditioners, which will also be referred to in
this instruction as the outdoor unit, uses HFC−410A
refrigerant. This outdoor unit must be installed with a
matching indoor unit and line set as outlined in the XC16
Engineering Handbook. XC16 Air Conditioners are
designed for use in thermal expansion valve (TXV)
systems.

NOTE − The XC16 outdoor unit is rated for 230V
applications only. A hard-start kit is required for
applications where the supply voltage is less than 230V.

Page 1

Unit Dimensions − Inches (mm)

UNIT SUPPORT

FEET

D

E

F

XC16 BASE WITH ELONGATED LEGS

C

DISCHARGE AIR

G

K

J

H

LIQUID LINE
CONNECTION

ELECTRICAL
INLETS

SUCTION LINE
CONNECTION

RUN

CAPACITOR

CONTACTOR

DISCHARGE

LINE

FILTER DRIER/

LIQUID LINE

CONNECTIONS

XC16 PARTS ARRANGEMENT

B

A

OUTDOOR FAN

COMPRESSOR

HIGH PRESSURE SWITCH

LOW PRESSURE SWITCH

VAPOR LINE

VAPOR VALVE AND GAUGE
PORT/SUCTION LINE
CONNECTIONS

2 (51)

08)

4−3/4
(121)

1 (25)

SIDE VIEW

4−1/4(1

SIDE VIEW

XC16 A B C D E F G H J K

−024

−048

−060

This product and/or the indoor unit it is matched
with may contain fiberglass wool.

Disturbing the insulation during installation,

39 (991) 30−1/2 (775) 35 (889)

45 (1143) 30−1/2 (775) 35 (889)

39 (991) 30−1/2 (775) 35 (889)

39 (991) 35−1/2 (902) 39−3/8 (1001) 16−7/8 (429) 8−3/4 (222) 3−1/8 (79) 30−3/4 (781) 4−5/8 (117) 3−3/4 (95) 26−7/8 (683)

WARNING

13−7/8 (352) 7−3/4 (197) 3−1/4 (83) 27−1/8 (689) 3−5/8 (92) 4−1/2 (114) 20−5/8 (524)−036

General Information

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

maintenance, or repair will expose you to fiberglass
wool dust. Breathing this may cause lung cancer.
(Fiberglass wool is known to the State of California
to cause cancer.)

Fiberglass wool may also cause respiratory, skin,
and eye irritation.

To reduce exposure to this substance or for further
information, consult material safety data sheets
available from address shown below, or contact
your supervisor.

Lennox Industries Inc.
P.O. Box 799900

When servicing or repairing HVAC components, ensure
caps and fasteners are appropriately tightened. Table 1
lists torque values for typical service and repair items.

Table 1. Torque Requirements

Part 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

Dallas, TX 75379−9900

Page 2

506101−01 07/09

USING MANIFOLD GAUGE SETS

When checking the system charge, only use a manifold
gauge set that features low loss anti−blow back fittings.
See figure 27 for a typical manifold gauge connection
setup.

Manifold gauge sets 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 on the high side and a low side of
30" vacuum to 250 psi with dampened speed to 500 psi.
Gauge hoses must be rated for use at up to 800 psi of
pressure with a 4000 psi burst rating.

OPERATING SERVICE VALVES

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

Each service valve is equipped with a service port which
has a factory−installed valve stem.

IMPORTANT

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.

1/12 TURN

12

1

2

3

4

7

5

6

9

10

8

11

1/6 TURN

12

1

2

3

4

7

5

6

11

10

9

8

Figure 1. Cap Tightening Distances

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

IMPORTANT

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

Operating Angle−Type Service Valve

To Access Angle−Type Service Port:

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

SERVICE PORT CAP

STEM CAP

SERVICE PORT

(VALVE STEM SHOWN
CLOSED) INSERT HEX
WRENCH HERE

SERVICE PORT

CLOSED TO BOTH

INDOOR AND

OUTDOOR UNITS

VALVE STEM

FRONT-SEATED

TO INDOOR

UNIT

TO OUTDOOR UNIT

CORE

Figure 2. Angle−Type Service Valve

(Font−Seated Closed)

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

2. Connect gauge to the service port.

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

S With Torque Wrench: Finger tighten and then

tighten per table 1.

S Without Torque Wrench: Finger tighten and use an

appropriately sized wrench to turn an additional
1/6 turn clockwise as illustrated in figure 1.

S With Torque Wrench: Finger tighten and then

tighten per table 1.

S Without Torque Wrench: Finger tighten and use an

appropriately sized wrench to turn an additional
1/6 turn clockwise as illustrated in figure 1.

To Open and Close Angle−Type Service Valve:

A valve stem cap protects the valve stem from
contamination and assures a leak−free seal.

SERVICE PORT CAP

SERVICE PORT

CORE

OPEN TO BOTH

INDOOR AND

OUTDOOR UNITS

TO INDOOR

UNIT

TO OUTDOOR UNIT

STEM CAP

Figure 3. Angle−Type Service Valve

(Back−Seated Opened)

1. Remove stem cap with a wrench.

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

SERVICE PORT

(VALVE STEM SHOWN OPEN)
INSERT HEX WRENCH HERE

Page 3

XC16 SERIES

3. Replace the stem cap and tighten as follows:

S With Torque Wrench: Tighten finger tight and then

tighten per table 1.

S Without Torque Wrench: Finger tighten and use an

appropriately sized wrench to turn an additional
1/12 turn clockwise as illustrated in figure 1.

Operating Ball−Type Service Valve

To Access Ball−Type 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 to the service port.

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

S With Torque Wrench: Finger tighten and then

tighten per table 1.

S Without Torque Wrench: Finger tighten and use an

appropriately sized wrench to turn an additional
1/6 turn clockwise as illustrated in figure 1.

To Open and Close Ball−Type Service Valve:

A valve stem cap protects the valve stem from
contamination and assures a leak−free seal.

1. Remove stem cap with a wrench.

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

3. Replace the stem cap and tighten as follows:

S With Torque Wrench: Finger tighten and then

tighten per table 1.

S Without Torque Wrench: Finger tighten and use an

appropriately sized to wrench turn an additional
1/12 turn clockwise as illustrated in figure 1.

OPEN TO LINE SET WHEN VALVE IS CLOSED,
TO BOTH LINE SET AND UNIT WHEN VALVE IS
OPEN.

TO INDOOR UNIT

Recovering Refrigerant from Existing
HCFC−22 System

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

METHOD 1:

Use this method if the existing outdoor unit is not equipped
with manual shut−off valves, and plan on using existing
HCFC−22 refrigerant to flush the system.

NOTE − Use recovery machine instructions for specific
setup requirements.

Perform the following task:

1. Disconnect all power to the existing outdoor unit.

2. Connect to the existing unit a gauge set, clean
recovery cylinder and a recovery machine. Use the
instructions provided with the recover machine on how
to setup the connections.

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

RECOVERY MACHINE

CLEAN RECOVERY
CYLINDER

Figure 5. Typical Refrigerant Recovery

(Method 1)

MANIFOLD GAUGES

OUTDOOR UNIT

TO OPEN ROTATE STEM
COUNTERCLOCKWISE 90°.

TO CLOSE ROTATE STEM
CLOCKWISE 90°.

SERVICE PORT

SERVICE PORT

CORE

SERVICE PORT CAP

TO OUTDOOR UNIT

Figure 4. Ball−Type Service Valve

506101−01 07/09

BALL (SHOWN
CLOSED)

VALV E
STEM

STEM CAP

METHOD 2:

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

IMPORTANT: Some system configurations may contain
higher than normal refrigerant charge due to either large
internal coil volumes, and/or long line sets. The following
conditions may cause the compressor to stop functioning:

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 cycled the compressor
OFF.

S Compressor can stop pumping due to tripped internal

pressure relief valve.

Page 4

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 suction 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:

1. Start the existing HCFC−22 system in the cooling
mode and close the liquid line valve.

2. Pump as much of the existing HCFC−22 refrigerant
with the compressor back into the outdoor unit until
you have reached the limitations of the outdoor
system. Turn the outdoor unit main power OFF and
use a recovery machine to remove the remaining
refrigerant in the system.

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

3. When the low side system pressures reach 0 psig,
close the suction line valve.

4. Check gauges after shutdown to confirm that the
valves are not allowing refrigerant to flow back into the
low side of the system.

Removing Existing Outdoor Unit

Perform the following task at the existing outdoor unit:

S Disconnect line set at the service valves.
S Disconnect electrical service at the disconnect switch.
S Remove old outdoor unit.

NOTES:

S Service clearance of 30 in. (762 mm) must be

maintained on one of the sides adjacent to the control
box.

S Clearance to one of the other three sides must be 36

in. (914 mm)

.

S Clearance to one of the remaining two sides may be

12 in. (305 mm) and the final side may be 6 in. (152

.

mm)

S 48 in. (1219 mm) clearance required on top of unit.
S A clearance of 24 in. (610 mm) must be maintained

between two units.

POSITIONING CONSIDERATIONS

Consider the following when positioning the unit:

CAUTION

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

S Some localities are adopting sound ordinances based

on the unit’s sound level registered from the adjacent
property, not from the installation property. Install the
unit as far as possible from the property line.

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 7.

INSTALL UNIT

AWAY FROM WIN-

DOWS

Positioning New Outdoor Unit

See Unit Dimensions on page for sizing mounting slab,
platforms or supports. Refer to figure 6 for mandatory
installation clearance requirements.

*

*

*

* SEE NOTES AFTER THIS
FIGURE FOR FURTHER DETAILS.

*

Figure 6. Installation Clearances

TWO 90° ELBOWS

INSTALLED IN LINE SET

WILL REDUCE LINE SET

VIBRATION.

Figure 7. Outside Unit Placement

PLACING OUTDOOR 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 8.

NOTE − If necessary for stability, anchor unit to slab as
described in Stabilizing Unit on Uneven Surfaces on page

7.

Page 5

XC16 SERIES

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

MOUNTING
SLAB

BASE

GROUND LEVEL

Figure 8. Slab Mounting at Ground Level

ELEVATING THE UNIT (SMALL−BASE UNITS)

If additional elevation is necessary, raise the unit by
extending the length of the unit support feet. This may be
done by cutting four equal true−cut lengths of Schedule
(SCH) 40, 4" (101.6mm) piping to the height required as
illustrated in figure 9.

BASE

LEG DETAIL

4" (101.6MM)
SCH 40 PIPING

Figure 9. Elevated Slab Mounting using Feet

Extenders (Small Base Units)

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.

The inside diameter of the 4" (101.6mm) piping is
approximately 0.25" (6.35mm) greater than the
pre−installed feet on the unit. Devise a shim that will take up
the space and hold the extenders onto the feet during this
procedure. Small strips of 0.125" (3.175mm) thick
adhesive foam may be used. One or two small 1"
(25.4mm) square strips should be adequate to hold the
extender in place.

ELEVATING THE UNIT (LARGER−BASE UNITS)

Unlike the small−base units which use round support feet,
the larger−base units are outfitted with elongated support
feet as illustrated in figure 10 which uses a similar method
for elevating the unit.

LEG DETAIL

2" (50.8MM) SCH 40
FEMALE THREADED
ADAPTER

Figure 10. Elevated Slab Mounting using

Feet Extenders (Larger Base Units)

If additional elevation is necessary, raise the unit by
extending the length of the unit support feet. This may be
achieved by using a 2" SCH 40 female threaded adapter.

The specified coupling will fit snuggly into the recessed
portion of the feet. Use additional 2" SCH 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

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.

Slab Side Mounting

#10 1/2" LONG SELF−

DRILLING SHEET

METAL SCREWS

STABILIZING

BRACKET (18 GAUGE

METAL − 2" WIDTH;

HEIGHT AS REQ’D)

#10 1−1/4" LONG

HEX HD SCREW

AND FLATWASHER

CONCRETE SLAB − USE PLASTIC
PLASTIC ANCHOR (HOLE DRILL
1/4")PLASTIC SLAB − NO PLASTIC
ANCHOR (HOLE DRILL 1/8")

COIL

BASE PAN

CORNER POST

Deck Top Mounting

STABILIZING BRACKET (18
GAUGE METAL − 2" WIDTH;
HEIGHT AS REQ’D); BEND
TO FORM RIGHT ANGLE

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

MINIMUM 1
PER SIDE

FOR EXTRA

STABILITY

Figure 11. Installing Stabilizer Brackets

506101−01 07/09

Page 6

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, remove two side
louvered panels to expose the unit base pan. Install the
brackets as illustrated in figure 11 using conventional

practices; replace the panels after installation is complete.

ROOF MOUNTING

Install unit at a minimum of four inches above the surface
of the roof. Care must be taken to ensure weight of unit is
properly distributed over roof joists and rafters. Either
redwood or steel supports are recommended.

Removing and Installing Panels

REMOVING PANELS

Remove the louvered panels as follows:

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.

1. Remove two screws, allowing the panel to swing open
slightly as illustrated in figure 12.

CAUTION

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.

NOTE − Hold the panel firmly throughout this procedure

2. Rotate bottom corner of panel away from hinge corner
post until lower three tabs clear the slots as illustrated
in figure 12, detail B.

3. Move panel down until lip of upper tab clears the top
slot in corner post as illustrated in figure 12, detail A.

INSTALLING PANEL

Install the louvered panels as follows:

SCREW

LIP

DETAIL A

DETAIL B

HOLES

ROTATE IN THIS DIRECTION;

THEN DOWN TO REMOVE

PANEL

Detail C

Figure 12. Removing/Installing Louvered

Panels (Details A, B and C)

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

ANGLE MAY BE TOO
EXTREME

PREFERRED ANGLE
FOR INSTALLATION

HOLD DOOR FIRMLY TO THE HINGED

SIDE TO MAINTAIN

FULLY−ENGAGED TABS

Figure 13. Removing/Installing Louvered

Panels (Detail D)

1. Position the panel almost parallel with the unit as
illustrated in figure 13, detail D with the screw side as
close to the unit as possible.

Page 7

XC16 SERIES

2. With a continuous motion slightly rotate and guide the
lip of top tab inward as illustrated in figure 12, details
A and C, then upward into the top slot of the hinge
corner post.

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

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

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

New or Replacement Line Set

This section provides information on installation or
replacement of existing line set. If line set are not being
installed then proceed to Brazing Connections on page 9.

If refrigerant lines are routed through a wall, 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. Also, consider the following when
placing and installing a high−efficiency air conditioner.

REFRIGERANT LINE SET

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

Table 2. Refrigerant Line Set

MATCHING WITH NEW OR EXISTING INDOOR COIL
AND LINE SET

The RFC1−metering line consisted of a small bore copper
line that ran from condenser to evaporator coil. Refrigerant
was metered into the evaporator by utilizing
temperature/pressure evaporation effects on refrigerant in
the small RFC line. The length and bore of the RFC line
corresponded to the size of cooling unit.

If the XC16 is being used with either a new or existing
indoor coil which is equipped with a liquid line which served
as a metering device (RFCI), the liquid line must be
replaced prior to the installation of the XC16 unit. Typically
a liquid line used to meter flow is 1/4" in diameter and
copper.

INSTALLING LINE SET
Line Set IsolationThis reference illustrates

procedures, which ensure proper refrigerant line set
isolation:

S Installation of line set on vertical runs is illustrated in

figure 14.

S Installation of a transition from horizontal to

vertical is illustrated in figure 15.

S Installation of line set on horizontal runs is

illustrated in figure 16.

IMPORTANT - REFRIGERANT LINES MUST NOT CONTACT WALL.

OUTSIDE WALL

WOOD BLOCK

BETWEEN STUDS

SUCTION LINE

LIQUID

LINE

WIRE TIE

INSIDE WALL

Field Connections Recommended Line Set

Model

−024

−036

−048

−060

Liquid

Line

3/8".
(10 mm)

3/8".
(10 mm)

3/8".
(10 mm)

Suction

Line

3/4"
(19 mm)

7/8"
(22 mm)

1−1/8".
(29 mm)

Liquid

Line

3/8"
(10 mm)

3/8"
(10 mm)

3/8"
(10 mm)

Suction

Line

3/4"
(19 mm)

7/8"
(22 mm)

1−1/8"
(29 mm)

L15 Line Set

L15−41
15 ft. − 50 ft.
(4.6 m − 15 m)

L15−65
15 ft. − 50 ft.
(4.6 m − 15 m)

Field
Fabricated

NOTE − When installing refrigerant lines longer than 50
feet, see the Lennox Refrigerant Piping Design and
Fabrication Guidelines, or contact Lennox Technical
Support Product Applications for assistance. To obtain the
correct information from Lennox, be sure to communicate
the following points:

S Model (XC16) and size of unit (e.g. −060).

S Line set diameters for the unit being installed as listed

in table 2 and total length of installation.

S Number of elbows and if there is a rise or drop of the

piping.

NOTE − SIMILAR INSTALLATION
PRACTICES SHOULD BE USED
IF LINE SET IS TO BE INSTALLED
ON EXTERIOR OF OUTSIDE
WALL.

SLEEVE

SUCTION LINE WRAPPED WITH

OUTSIDE

WALL

PVC PIPE FIBERGLASS INSULATION

ARMAFLEX

LIQUID LINE

IMPORTANT! REFRIGERANT

LINES MUST NOT CONTACT

CAULK

STRUCTURE.

Figure 14. Refrigerant Line Set: Installing
Vertical Runs (New Construction Shown)

STRAP

SLEEVE

WIRE TIE

WOOD BLOCK

WIRE TIE

STRAP

506101−01 07/09

Page 8

ANCHORED HEAVY NYLON
WIRE TIE OR AUTOMOTIVE
MUFFLER-TYPE HANGER

WALL
STUD

METAL SLEEVE

MUFFLER-TYPE HANGER

AUTOMOTIVE

STRAP LIQUID LINE
TO SUCTION LINE

LIQUID LINE

SUCTION LINE − WRAPPED
IN ARMAFLEX

TO HANG LINE SET FROM JOIST OR
RAFTER, USE EITHER METAL STRAPPING
MATERIAL OR ANCHORED HEAVY NYLON
WIRE TIES.

STRAPPING MATERIAL

(AROUND SUCTION

LINE ONLY)

FLOOR JOIST OR

ROOF RAFTER

TAPE OR
WIRE TIE

8 FEET

FLOOR JOIST OR

ROOF RAFTER

METAL

SLEEVE

WIRE TIE
(AROUND
SUCTION LINE
ONLY)

TAPE OR

8 FEET

STRAP THE SUCTION LINE TO
THE JOIST OR RAFTER AT 8 FEET
INTERVALS THEN STRAP THE
LIQUID LINE TO THE SUCTION
LINE.

WIRE TIE

Figure 15. Refrigerant Line Set: Transition

from Vertical to Horizontal

1

CUT AND DEBUR

2

REMOVE CAP AND CORE FROM

BOTH LIQUID AND SUCTION

INDOOR UNIT

7

INSTALL CORE ONLY FOR

BOTH SERVICE PORTS AFTER

THEY HAVE COOLED.

6

BRAZE LINE SET

Figure 17. Brazing Connections

SERVICE PORTS

SERVICE PORT MUST BE

OPEN TO ALLOW EXIT
POINT FOR NITROGEN

SUCTION LINE

LIQUID LINE

5

Figure 16. Refrigerant Line Set: Installing

Horizontal Runs

3

ATTACH

GAUGES

SERVICE

VALVE

SERVICE

VALVE

OUTDOOR

UNIT

FLOW NITROGEN

NITROGEN

4

WRAP

SERVICE

VALV E

Brazing Connections

Use the following procedure to braze the line set to the new
air conditioner unit. Figure 17 on page 9 is provided as a
general guide for preparing to braze the line set to the air
conditioner unit.

1. Cut ends of the refrigerant lines square (free from
nicks or dents). Debur the ends. The pipe must remain
round, do not pinch end of the line.

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.

Page 9

XC16 SERIES

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).

IMPORTANT

Repeat procedure starting at paragraph 4 for brazing the
suction line to service port valve.

7. After all connections have been brazed, disconnect
manifold gauge set the from service ports and remove
wrapping. Reinstall the service port core for both of the
outdoor unit’s service valves.

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.

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.

2. Remove service cap and core from both the suction
and liquid line service ports.

3. Connect gauge low pressure side to liquid line service
valve.

4. To protect components during 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.
Also, shield the light maroon R−410A sticker.

5. 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 suction service
valve.

NOTE − The fixed orifice or TXV metering device at the
indoor unit will allow low pressure nitrogen to flow through
the system.)

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

6. Braze the liquid line to the liquid line service valve.
Turn off nitrogen flow.

Removing Indoor Unit Metering Device

Remove the existing HCFC−22 fixed orifice or TXV from
the indoor coil. The existing indoor unit HCFC−22 metering
device is not approved for use with HFC−410A refrigerant
and may prevent proper flushing.

REPLACEMENT PARTS

If replacement parts are necessary for the indoor unit,
order kit 69J46 (LB−95325A). The kit includes:

LIQUID LINE ORIFICE HOUSINGS (10)

TEFLON RINGS (20)

LIQUID LINE ASSEMBLIES

(INCLUDES STRAINER) (10)

BRASS NUTS (10)

LIQUID LINE

ASSEMBLY

Figure 18. 69J46 Kit Components

TYPICAL FIXED ORIFICE REMOVAL PROCEDURE

Use the following procedures to remove a fixed orifice
metering device from an existing indoor unit:

DISTRIBUTOR TUBES

LIQUID LINE ORIFICE HOUSING

DISTRIBUTOR

ASSEMBLY

VALVE STEM

TEFLON RING

VALVE STEM CAP

FIXED
ORIFICE

REMOVE AND DISCARD
VALVE STEM ASSEMBLY
(IF PRESENT)

LIQUID LINE ASSEMBLY

(INCLUDES STRAINER)

(Uncased Coil Shown)

Figure 19. Typical Fixed Orifice Removal

1. On fully cased coils, remove the coil access and
plumbing panels.

2. Remove any shipping clamps holding the liquid line
and distributor assembly.

3. Using two wrenches, disconnect liquid line from liquid
line orifice housing. Take care not to twist or damage
distributor tubes during this process.

PISTON
RETAINER

STRAINER

COPPER
TUBE

BRASS NUT

506101−01 07/09

Page 10

4. Remove and discard fixed orifice, valve stem
assembly if present and Teflon ring as illustrated in
figure 19.

5. Use a field−provided fitting to temporary reconnect the
liquid line to the indoor unit’s liquid line orifice housing.

TYPICAL TXV REMOVAL PROCEDURE

Use following procedure for a typical TXV removal:

(Uncased Coil Shown)

TWO PIECE

PATCH PLATE

(UNCASED COIL

ONLY)

DISTRIBUTOR

TUBES

DISTRIBUTOR

ASSEMBLY

LIQUID LINE

ORIFICE

HOUSING

EQUALIZER
LINE

STUB END

TXV

TEFLON
RING

LIQUID LINE ASSEMBLY

WITH BRASS NUT

TEFLON

RING

SENSING

LINE

IMPORTANT

If this unit is being matched with an approved line
set or indoor unit coil which was previously
charged with mineral oil, or if it is being matched
with a coil which was manufactured before
January of 1999, the coil and line set must be
flushed prior to installation. Take care to empty all
existing traps. Polyol ester (POE) oils are used in
Lennox units charged with HFC−410A refrigerant.
Residual mineral oil can act as an insulator,
preventing proper heat transfer. It can also clog
the expansion device, and reduce the system
performance and capacity.

Failure to properly flush the system per the
instructions below will void the warranty.

IMPORTANT

The Environmental Protection Agency (EPA)
prohibits the intentional venting of HFC refrigerants
during maintenance, service, repair and disposal of
appliance. Approved methods of recovery,
recycling or reclaiming must be followed.

MALE EQUALIZER

LINE FITTING

SENSING

BULB

SUCTION

LINE

LIQUID

LINE

Figure 20. Typical TXV Removal

1. On fully cased coils, remove the coil access and
plumbing panels.

2. Remove any shipping clamps holding the liquid line
and distributor assembly.

3. Disconnect the equalizer line from the TXV equalizer
line fitting on the suction line.

4. Remove the suction line sensing bulb as illustrated in
figure 20.

5. Disconnect the liquid line from the TXV at the liquid line
assembly.

6. Disconnect the TXV from the liquid line orifice housing.
Take care not to twist or damage distributor tubes
during this process.

7. Remove and discard TXV and the two Teflon rings as
illustrated in figure 20.

8. Use a field−provided fitting to temporary reconnect the
liquid line to the indoor unit’s liquid line orifice housing.

Flushing the System

If the original system used:

S HCFC−22 refrigerant, then flush the system using the

procedure provided in this section.

S HFC−410A refrigerant, then proceed to Installing New

Refrigerant Metering Device.

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

SUCTION LINE

SERVICE VALVE

EXISTING

INDOOR

UNIT

LIQUID LINE SERVICE VALVE

RECOVERY

CYLINDER

SUCTION

LIQUID

NOTE − The inverted HCFC−22 cylinder must contain at least the same
amount of refrigerant as was recovered from the existing system.

NEW

OUTDOOR

UNIT

OPENED

RECOVERY MACHINE

Figure 21. Typical Flushing Connection

MANIFOLD

LOW

PRESSURE

TANK
RETURN

INLET

DISCHARGE

GAUGE

PRESSURE

HIGH

CLOSED

IMPORTANT

The line set and indoor unit coil must be flushed
with at least the same amount of clean refrigerant
that previously charged the system. Check the
charge in the flushing cylinder before proceeding.

CAUTION

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

Page 11

XC16 SERIES

REQUIRED EQUIPMENT

Equipment required to flush the existing line set and indoor
unit coil:

S Two clean HCFC−22 recovery bottles,
S Oilless recovery machine with pump-down feature,
S Two gauge sets (one for HCFC−22; one for

HFC−410A).

PROCEDURE

1. Connect the following:

S HCFC−22 cylinder with clean refrigerant to the

suction service valve,

S HCFC−22 gauge set to the liquid line valve,
S Recovery machine with an empty recovery tank to

the gauge set.

2. Set the recovery machine for liquid recovery and start
the recovery 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.

3. Invert the cylinder of clean HCFC−22 and open its
valve to allow liquid refrigerant to flow into the system
through the suction 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.

4. After all of the liquid refrigerant has been recovered,
switch the recovery machine to suction recovery so
that all of the HCFC−22 suction is recovered. Allow the
recovery machine to pull a vacuum on the system.

5. 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.

6. Use dry nitrogen to break the vacuum on the
refrigerant lines and indoor unit coil before removing
the recovery machine, gauges and refrigerant drum.

Installing New Indoor Unit Metering
Device

XC16 units can be configured for use in with HFC−410A
fixed orifice or TXV metering devices. This section
provides instructions on installing either a fixed orifice or
TXV refrigerant metering device.

TXV (1)

HEX HEAD BOLTS

AND NUTS (2)

TEFLON
RINGS (2)

COPPER

MOUNTING

STRAP (1)

Figure 23. TXV Kit Components

TYPICAL TXV INSTALLATION PROCEDURE

The TXV 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 TXV in a
manner that will provide access for field servicing of the
TXV. Refer to Figure 24 for reference during installation of
TXV unit.

To prevent any possibility of water damage, properly
insulate all parts of the TXV assembly that may sweat due
to temperature differences between the valve and its
surrounding ambient temperatures.

TWO PIECE

PATCH PLATE

(UNCASED COIL

ONLY)

DISTRIBUTOR

TUBES

DISTRIBUTOR

ASSEMBLY

(Uncased Coil Shown)

LIQUID LINE

ORIFICE

HOUSING

EQUALIZER
LINE

STUB END

TXV

TEFLON
RING

LIQUID LINE ASSEMBLY

WITH BRASS NUT

TEFLON

RING

SENSING

LINE

1/8 TURN

10

8

11

12

7

6

9

10

8

11

12

1

2

3

9

4

7

5

6

Figure 22. Tightening Distance

XC16 ENGINEERING HANDBOOK

See the XC16 Engineering Handbook for approved
indoor/outdoor match−ups, applicable TXV kit and
application information. The following is the typical
contents of a TXV kit:

506101−01 07/09

1/2 TURN

1

2

3

4

5

MALE EQUALIZER LINE

FITTING (SEE FIGURE 26
FOR FURTHER DETAILS)

SENSING BULB INSULATION IS
REQUIRED IF MOUNTED EXTERNAL
TO THE COIL CASING. SEE FIGURE 25
FOR BULB POSITIONING.

SUCTION
LINE

LIQUID

LINE

Figure 24. Typical TXV Installation

1. Remove the field−provided fitting that temporary
reconnected the liquid line to the indoor unit’s
distributor assembly.

2. Install one of the provided Teflon rings around the
stubbed end of the TXV and lightly lubricate the
connector threads and expose surface of the Teflon
ring with refrigerant oil.

Page 12

3. Attach the stubbed end of the TXV 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 figure 22, or 20 ft−lb.

4. Place the remaining Teflon ring around the other end
of the TXV. Lightly lubricate connector threads and
expose surface of the Teflon ring with refrigerant oil.

5. Attach the liquid line assembly to the TXV. Finger
tighten and use an appropriately sized wrench to turn
an additional 1/2 turn clockwise as illustrated in figure
22, or 20 ft−lb.

6. Attach the suction line sensing bulb in the proper
orientation as illustrated in figure 25 using the clamp
and screws provided.

NOTE − Insulating the sensing bulb once installed may be
required when the bulb location is external to the coil
casing.

SUCTION LINE

BULB

12

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

BULB

8. Connect the equalizer line from the TXV to the
equalizer suction port on the suction line. Finger
tighten the flare nut plus 1/8 turn (7 ft−lbs) as illustrated
in figure 22.

Testing for Leaks

After the line set has been connected to both the indoor
and outdoor units, check the line set connections and
indoor unit for leaks. Use the following procedure to test for
leaks:

IMPORTANT

Leak detector must be capable of sensing HFC
refrigerant.

WARNING

Refrigerant can be harmful if it is inhaled.
Refrigerant must be used and recovered
responsibly.

Failure to follow this warning may result in personal
injury or death.

SUCTION LINE

12

BULB

ON 7/8" AND LARGER LINES,
MOUNT SENSING BULB AT
EITHER THE 4 OR 8 O’CLOCK
POSITION. NEVER MOUNT
ON BOTTOM OF LINE.

BULB

NOTE − NEVER MOUNT ON
BOTTOM OF LINE.

Figure 25. TXV Sensing Bulb Installation

7. Remove and discard either the flare seal cap or flare
nut with copper flare seal bonnet from the equalizer
line port on the suction line as illustrated in figure 26.

IMPORTANT

When removing the flare nut, ensure that the copper
flare seal bonnet is removed.

FLARE SEAL

CAP

OR

MALE BRASS EQUALIZER

Figure 26. Copper Flare Seal Bonnet Removal

FLARE NUT

COPPER

FLARE SEAL

BONNET

LINE FITTING

SUCTION LINE

WARNING

Fire, Explosion and Personal Safety
Hazard.

Failure to follow this warning could
result in damage, personal injury or
death.

Never use oxygen to pressurize or
purge refrigeration lines. Oxygen,
when exposed to a spark or open
flame, can cause damage by fire and/
or an explosion, that could result in
personal injury or death.

1. Connect an HFC−410A manifold gauge set high
pressure hose to the suction valve service port.

NOTE − Normally, the high pressure hose is connected to
the liquid line port; however, connecting it to the suction
port better protects the manifold gauge set from high
pressure damage.

2. With both manifold valves closed, connect the cylinder
of HFC−410A refrigerant to the center port of the
manifold gauge set. Open the valve on the HFC−410A
cylinder (suction only).

3. Open the high pressure side of the manifold to allow
HFC−410A into the line set and indoor unit. Weigh in
a trace amount of HFC−410A. [A trace amount is a

maximum of two ounces (57 g) refrigerant or three
pounds (31 kPa) pressure]. Close the valve on the

HFC−410A cylinder and the valve on the high pressure
side of the manifold gauge set. Disconnect the
HFC−410A cylinder.

4. Connect a cylinder of dry nitrogen with a pressure
regulating valve to the center port of the manifold
gauge set.

Page 13

XC16 SERIES

5. Adjust dry nitrogen pressure to 150 psig (1034 kPa).
Open the valve on the high side of the manifold gauge
set in order to pressurize the line set and the indoor unit.

6. After a few minutes, open one of the service valve
ports and verify that the refrigerant added to the
system earlier is measurable with a leak detector.

NOTE − Amounts of refrigerant will vary with line lengths.

7. Check all joints for leaks.

8. Purge dry nitrogen and HFC−410A mixture.

9. Correct any leaks and recheck.

10. After leak testing disconnect gauges from service
ports.

Evacuating the System

WARNING

Danger of Equipment Damage. Avoid deep
vacuum operation. Do not use compressors to
evacuate a system. Extremely low vacuums can
cause internal arcing and compressor failure.
Damage caused by deep vacuum operation will
void warranty.

IMPORTANT

Use a thermocouple or thermistor electronic vacuum
gauge that is calibrated in microns. Use an instrument
capable of accurately measuring down to 50 microns.

Evacuating the system of non−condensables is critical for
proper operation of the unit. Non−condensables are
defined as any gas that will not condense under
temperatures and pressures present during operation of
an air conditioning system. Non−condensables and water
suction combine with refrigerant to produce substances
that corrode copper piping and compressor parts.

1. Connect manifold gauge set to the service valve ports
as follows:

S low pressure gauge to suction line service valve
S high pressure gauge to liquid line service valve

2. Connect micron gauge.

3. Connect the vacuum pump (with vacuum gauge) to
the center port of the manifold gauge set.

4. Open both manifold valves and start the vacuum
pump.

5. Evacuate the line set and indoor unit to an absolute
pressure of 23,000 microns (29.01 inches of
mercury).

NOTE − During the early stages of evacuation, it is
desirable to close the manifold gauge valve at least once to
determine if there is a rapid rise in sure indicates a
relatively large leak. If this occurs, repeat the leak testing
procedure.

NOTE − The term absolute pressure means the total
actual pressure within a given volume or system, above
the absolute zero of pressure. Absolute pressure in a
vacuum is equal to atmospheric pressure minus vacuum
pressure.

6. When the absolute pressure reaches 23,000 microns
(29.01 inches of mercury), close the manifold gauge
valves, turn off the vacuum pump and disconnect the
manifold gauge center port hose from vacuum pump.
Attach the manifold center port hose to a dry nitrogen
cylinder with pressure regulator set to 150 psig (1034
kPa) and purge the hose. Open the manifold gauge
valves to break the vacuum in the line set and indoor
unit. Close the manifold gauge valves.

7. Shut off the dry nitrogen cylinder and remove the
manifold gauge hose from the cylinder. Open the
manifold gauge valves to release the dry nitrogen from
the line set and indoor unit.

8. Reconnect the manifold gauge to the vacuum pump,
turn the pump on, and continue to evacuate the line set
and indoor unit until the absolute pressure does not
rise above 500 microns (29.9 inches of mercury) within
a 20−minute period after shutting off the vacuum pump
and closing the manifold gauge valves.

9. When the absolute pressure requirement above has
been met, disconnect the manifold hose from the
vacuum pump and connect it to an upright cylinder of
HFC−410A refrigerant. Open the manifold gauge valve
1 to 2 psig in order to release the vacuum in the line set
and indoor unit.

10. Close manifold gauge valves and shut off the
HFC−410A cylinder and remove the manifold gauge
set.

Servicing Unit Delivered Void of Charge

If the system is void of refrigerant, clean the system using
the procedure described below.

1. Use nitrogen to pressurize the system and check for
leaks. Repair all leaks.

2. Evacuate the system to remove as much of the
moisture as possible.

3. Use nitrogen to break the vacuum and install a new
filter drier in the system.

4. Evacuate the system again. Then, weigh the
appropriate amount of HFC−410A refrigerant as listed
on unit nameplate into the system.

506101−01 07/09

Page 14

Figure 1. Typical Wiring Diagram

5. Monitor the system to determine the amount of
moisture remaining in the oil. It may be necessary to
replace the filter drier several times to achieve the
required dryness level. If system dryness is not

verified, the compressor will fail in the future.

Electrical Connections

WARNING

Electric Shock Hazard. Can cause
injury or death.

Line voltage is present at all
components on units with single-pole
contactors, even when unit is not in
operation!

Unit may have multiple power
supplies. Disconnect all remote
electric power supplies before
opening access panel.

Unit must be grounded in accordance
with national and local codes.

In the U.S.A., wiring must conform with current local codes
and the current National Electric Code (NEC). In Canada,
wiring must conform with current local codes and the current
Canadian Electrical Code (CEC).

Refer to the furnace or blower coil installation instructions
for additional wiring application diagrams and refer to unit
nameplate for minimum circuit ampacity and maximum
overcurrent protection size.

TRANSFORMER − 24VAC

Use the transformer provided with the furnace or coil blower
for low-voltage control power (24 − 40VAC minimum)

NOTE − The addition of accessories to the system could
exceed the 40VAC power requirement of the
factory-provided transformer. Measure the system’s
current and voltage after installation is complete to
determine transformer loading. If loading exceeds the
factory-provided transformer capacity, a larger
field-provided transformer will need to be installed in the
system.

Page 15

XC16 SERIES

WIRING CONNECTIONS

1. Install line voltage power supply to unit from a properly
sized disconnect switch. Any excess high voltage field
wiring should be trimmed or secured away from the
low voltage field wiring as illustrated in figure 2.

HIGH VOLTAGE
FIELD WIRING

WIRE TIES

GROMMET

LOW VOLTAGE
FIELD WIRING

FACTORY
WIRING

Table 1. Wire Run Lengths

Wire run length AWG # Insulation type

less than 100’ (30m) 18

more than 100’ (30m) 16

color−coded, temperature
rating 35ºC minimum

6. Install low−voltage wiring from outdoor to indoor unit
and from thermostat to indoor unit.

7. Do not bundle any excess 24V control wire inside
control box. Run control wire through installed wire tie
and tighten wire tie to provided low voltage strain relief
and to maintain separation of field installed low and
high voltage circuits as illustrated in figure 2 on page

16.

Start−Up, Testing and Charging
Procedures

Figure 2. Separating High/Low Voltage

(Typical Field Wiring)

NOTE − To facilitate conduit, a hole is located in the
bottom of the control box.

GROUND

230 / 60 / 1

WARNING! − ELECTRIC SHOCK HAZARD. CAN CAUSE INJURY OR DEATH.
UNIT MUST BE GROUNDED IN ACCORDANCE WITH NATIONAL AND
LOCAL CODES.

NOTE − FOR USE WITH COPPER CONDUCTORS ONLY. REFER TO UNIT
RATING PLATE FOR MINIMUM CIRCUIT AMPACITY AND MAXIMUM
OVER-CURRENT PROTECTION SIZE.

NOTE − HARD START KIT (INCLUDES OPTIONAL COMPONENTS SHOWN)
IS REQUIRED IN APPLICATIONS WHERE SUPPLY VOLTAGE IS LESS THAN
230 VOLTS.

Figure 3. Typical Field Wiring Diagram

2. Ground unit at unit disconnect switch or to an earth
ground.

3. Connect conduit to the unit using provided conduit
bushing.

NOTE − Units are approved for use only with copper
conductors. 24VAC, Class II circuit connections are
made in the low voltage junction box. See figure 3 for
field wiring and figure 1 on page 15 for typical wiring. A
complete unit wiring diagram is located inside the unit
control box cover.

4. Install room thermostat (ordered separately) on an
inside wall approximately in the center of the
conditioned area and 5 feet (1.5 m) from the floor. It
should not be installed on an outside wall or where it
can be affected by sunlight, drafts or vibrations.

5. For proper voltages, select thermostat wire gauge per
the following chart:

IMPORTANT

If unit is equipped with a crankcase heater, it should
be energized 24 hours before unit start−up to
prevent compressor damage as a result of slugging.

1. Rotate fan to check for binding.

2. Inspect all factory− and field−installed wiring for loose
connections.

3. After evacuation is complete, open the liquid line and
suction line service valves to release the refrigerant
charge (contained in outdoor unit) into the system.

4. Replace the stem caps and secure finger tight, then
tighten an additional one-sixth (1/6) of a turn.

5. Check voltage supply at the disconnect switch. The
voltage must be within the range listed on the unit’s
nameplate. If not, do not start the equipment until you
have consulted the power company and the voltage
condition has been corrected.

6. Set the thermostat for a cooling demand. Turn on
power to the indoor blower and close the outdoor unit
disconnect switch to start the unit.

7. Recheck voltage while the unit is running. Power must
be within range shown on the nameplate.

8. Check system for sufficient refrigerate by using the
procedures listed under this section.

SETTING UP TO CHECK CHARGE

1. Close manifold gauge set valves. Connect the center
manifold hose to an upright cylinder of HFC−410A.

2. Connect the manifold gauge set to the unit’s service
ports as illustrated in figure 27.

D low pressure gauge to suction line service port.
D high pressure gauge to liquid line service port.

INDOOR COIL AIRFLOW CHECK

Check indoor coil airflow using the Delta−T (DT) process
as illustration in figure 28.

DETERMINING CHARGE METHOD

To determine the correct charging method, use the
illustration in figure 29.

506101−01 07/09

Page 16

OUTDOOR UNIT

(Uncased Coil Shown)

LOW

PRESSURE

GAUGE MANIFOLD

Temp.
of air
entering
indoor
coil ºF

A

Wet−bulb ºF

C

53º

DRY

BULB

HIGH

PRESSURE

TO

HFC−410A

DRUM

80 24 24 24 23 23 22 22 22 20 19 18 17 16 15
78 23 23 23 22 22 21 21 20 19 18 17 16 15 14
76 22 22 22 21 21 20 19 19 18 17 16 15 14 13
74 21 21 21 20 19 19 18 17 16 16 15 14 13 12

Dry−bulb

72 20 20 19 18 17 17 16 15 15 14 13 12 11 10

70 19 19 18 18 17 17 16 15 15 14 13 12 11 10

57 58 59 60 61 62 63 64 65 66 67 68 69 70

T

Drop

19º

All temperatures are

expressed in ºF

OUTDOOR

COIL

SUCTION LINE
SERVICE VALVE

FILTER

DRIER

LIQUID LINE

SERVICE VALVE

COMPRESSOR

Figure 27. Typical Manifold Gauge Connection Setup

Delta−T

air flowair flow

INDOOR
COIL

B

A

72º

B

WET

BULB

DRY

BULB

64º

1. Determine the desired DTMeasure entering air temperature

using dry bulb (A) and wet bulb (B). DT is the intersecting value of A
and B in the table (see triangle).

2. Find temperature drop across coilMeasure the coil’s dry bulb
entering and leaving air temperatures (A and C). Temperature Drop
Formula: (T

) = A minus C.

Drop

3. Determine if fan needs adjustmentIf the difference between the

measured T
adjustment is needed. See examples: Assume DT = 15 and A temp. =

and the desired DT (T

Drop

72º, these C temperatures would necessitate stated actions:
Cº T

– DT = ºF ACTION

Drop

53º 19 – 15 = 4 Increase the airflow
58º 14 – 15 = −1 (within +3º range) no change
62º 10 – 15 = −5 Decrease the airflow

4. Adjust the fan speedSee indoor unit instructions to

increase/decrease fan speed.

Changing air flow affects all temperatures; recheck temperatures to
confirm that the temperature drop and DT are within +3º.

TXV

–DT) is within +3º, no

Drop

Figure 28. Checking Indoor Airflow over Evaporator Coil using Delta−T Chart

START: Determine how refrigerant is metered

WHEN TO CHARGE?

S Warm weather best
S Can charge in colder weather

CHARGE METHOD? Determine by:

S Metering device type
S Outdoor ambient temperature

REQUIREMENTS:

S Sufficient heat load in structure
S Indoor temperature between 70-80ºF (21−26ºC)
S Manifold gauge set connected to unit
S Thermometers:

− to measure outdoor ambient temperature

− to measure liquid line temperature

− to measure suction line temperature

Figure 29. Determining Charging Method

Page 17

OUTDOOR AMBIENT

TEMPERATURE

65ºF (18.3ºC)

and ABOVE

APPROACH OR

SUBCOOLING

(SECOND STAGE − HIGH

CAPACITY)

TXV

64ºF (17.7ºC)

and BELOW

WEIGH-IN

XC16 SERIES

START: Measure outdoor ambient temperature

USE EITHER APPROACH

OR SUBCOOLING

METHOD

65ºF

and

ABOVE

WEIGH IN TXV

Refrigerant Charge per Line Set Length

Liquid Line

Set Diameter

3/8" (9.5 mm)

NOTE − *If line length is greater than 15 ft. (4.6 m), add this
amount. If line length is less than 15 ft. (4.6 m), subtract this
amount.

Ounces per 5 feet (g per 1.5 m)

adjust from 15 feet (4.6 m) line set*

3 ounce per 5’ (85 g per 1.5 m)

Figure 30. Weigh In Method

ABOVE or

BELOW

64ºF and

BELOW

1. Check Liquid and suction line pressures

2. Compare unit pressures with Table 2,
Normal Operating Pressures.

3. Conduct leak check; evacuate as
previously outlined.

4. Weigh in the unit nameplate charge plus
any charge required for line set differences
over feet.

This nameplate is for illustration purposes
only. Go to actual nameplate on outdoor
unit for charge information.

START: Measure outdoor ambient temperature

USE WEIGH-IN METHOD

DO NOT CHARGE UNIT

Weigh-in or remove refrigerant

(Results of charging at low

based upon line length

temperatures not reliable)

64ºF and

ABOVE or

BELOW

BELOW

BLOCK OUTDOOR COIL: [sometimes necessary with lower
temperatures] Use cardboard or plastic sheet to restrict the airflow
through the outdoor coil to achieve pressures from 325−375 psig
(2240−2585 kPa). Higher pressures are needed to check charge.
Block equal sections of air intake panels and move coverings
sideways until the liquid pressure is in the above noted ranges.

If refrigerant is added
or removed, verify
charge using the
Approach Method.

If value is LESS
than shown, add
refrigerant.

If value is MORE
than shown, remove
refrigerant.

MORE or

LESS

65ºF

and

ABOVE

1. Confirm proper airflow across coil using figure

28.

2. Compare unit pressures with Table 2, Normal

Operating Pressures − Second Stage (High
Capacity).

3. Set thermostat to call for heat (must have a
cooling load between 70-80ºF (21−26ºC)

4. Connect gauge set

5. Measure outdoor ambient temperature

6. When heat demand is satisfied, set thermostat to
call for second stage (high capacity) cooling.

7. Allow temperatures and pressures to stabilize.

NOTE − If necessary, block outdoor coil to
maintain 325 − 375 psig.

8. Record liquid line temperature:

LIQº = ______

9. Measure liquid line pressure and use the value to
determine saturation temperature (see table 3):

SATº = ______

10. Subtract to determine subcooling (SCº):

SATº_____ − LIQº _____ = SCº _____

11. Compare results with table below.

SCº (Subcooling) Values (F:+/−1.0° [C: +/−0.6°])

Second Stage (High Capacity)

Models
ºF (ºC)* −024 −036 −048 −060
Any 5 (2.7) 6 (3.3) 6 (3.3) 9 (5.0)
*Temperature of air entering outdoor coil

Figure 31. Subcooling TXV Charge  Second Stage (High Capacity)

506101−01 07/09

Page 18

START: Measure outdoor ambient temperature

USE WEIGH-IN METHOD

DO NOT CHARGE UNIT

Weigh-in or remove refrigerant

(Results of charging at low

based upon line length

temperatures not reliable)

64ºF and

BELOW

If refrigerant is added
or removed, retest to
confirm that unit is
properly charged.

If value is greater than shown (high approach),
add refrigerant; if less than shown (liquid
temperature too close to ambient temperature,
low approach), remove refrigerant.

Figure 32. Approach TXV Charge  Second Stage (High Capacity)

ABOVE or

BELOW

1. Confirm proper airflow across coil using figure

65ºF

and

ABOVE

28.

2. Compare unit pressures with Table 2, Normal

Operating Pressures − Second Stage (High
Capacity).

3. Set thermostat to call for heat (must have a
cooling load between 70-80ºF (21−26ºC).

4. Connect gauge set.

5. When heat demand is satisfied, set thermostat
to call for second stage (high capacity) cooling.

6. Allow temperatures and pressures to stabilize.

7. Record outdoor ambient temperature:

AMBº =_________

8. Record liquid line temperature:

LIQº = __________

9. Subtract to determine approach (APPº):

LIQº_____ − AMBº _____ = APPº_____

10. Compare results with table below.

APPº (Approach) Values(F:+/−1.0° [C: +/−0.6°])

Second Stage (High Capacity)

Models
ºF (ºC)* −024 −036 −048 −060
Any 6 (3.3) 6 (3.3) 8 (4.4) 4 (2.2)
*Temperature of air entering outdoor coil

Table 2. Normal Operating Pressures In PSIG (Liquid +/− 10 and Suction+/− 5 PSIG)*

Use this table to perform maintenance checks; it is not a procedure for
charging the system. Minor variations in these pressures may be due to

IMPORTANT

differences in installations. Significant deviations could mean that the system
is not properly charged or that a problem exists with some component in the
system.

Temp. of air
entering
outdoor coil
5F (5C)

Liquid Suction Liquid Suction Liquid Suction Liquid Suction

−024 −036 −048 −060

First Stage (Low Capacity)

65 (18.3) 215 144 226 142 224 142 215 136

75 (23.9) 247 146 261 144 258 144 250 139

85 (29.4) 288 148 304 145 299 146 291 142

95 (35.0) 332 151 352 147 345 148 337 144

105 (40.6) 381 153 405 150 395 150 388 146

115 (46.1) 435 155 460 150 450 153 444 148

Second Stage (High Capacity)

65 (18.3) 225 140 228 144 235 135 220 130

75 (23.9) 258 142 262 146 269 137 256 133

85 (29.4) 301 144 306 148 313 139 299 136

95 (35.0) 346 146 353 150 361 141 347 138

105 (40.6) 397 149 405 151 412 143 402 141

115 (46.1) 452 151 462 154 471 146 462 143

*These are typical pressures only. Indoor indoor match up, indoor air quality, and indoor load will cause the pressures to vary.

Page 19

XC16 SERIES

Table 3. HFC−410A Temperature (°F) − Pressure (Psig)

Psig °F Psig °F Psig °F Psig °F Psig °F Psig °F Psig °F Psig

°F

32 100.8 48 137.1 63 178.5 79 231.6 94 290.8 11 0 365.0

33 102.9 49 139.6 64 181.6 80 235.3 95 295.1 111 370.0 126 451.8 142 552.3

34 105.0 50 142.2 65 184.3 81 239.0 96 299.4 11 2 375.1 127 457.6 143 559.1

35 107.1 51 144.8 66 187.7 82 242.7 97 303.8 11 3 380.2 128 463.5 144 565.9

36 109.2 52 147.4 67 190.9 83 246.5 98 308.2 11 4 385.4 129 469.5 145 572.8

37 111.4 53 150.1 68 194.1 84 250.3 99 312.7 11 5 390.7 130 475.6 146 579.8

38 113.6 54 152.8 69 197.3 85 254.1 100 317.2 11 6 396.0 131 481.6 147 586.8

39 115.8 55 155.5 70 200.6 86 258.0 101 321.8 11 7 401.3 132 487.8 148 593.8

40 118.0 56 158.2 71 203.9 87 262.0 102 326.4 11 8 406.7 133 494.0 149 601.0

41 120.3 57 161.0 72 207.2 88 266.0 103 331.0 119 412.2 134 500.2 150 608.1

42 122.6 58 163.9 73 210.6 89 270.0 104 335.7 120 417.7 135 506.5 151 615.4

43 125.0 59 166.7 74 214.0 90 274.1 105 340.5 121 423.2 136 512.9 152 622.7

44 127.3 60 169.6 75 217.4 91 278.2 106 345.3 122 428.8 137 519.3 153 630.1

45 129.7 61 172.6 76 220.9 92 282.3 107 350.1 123 434.5 138 525.8 154 637.5

46 132.2 62 175.4 77 224.4 93 286.5 108 355.0 124 440.2 139 532.4 155 645.0

47 134.6 78 228.0 109 360.0 140 539.0

125 445.9

141 545.6

System Operation

The outdoor unit and indoor blower cycle on demand from
the room thermostat. When the thermostat blower switch
is in the ON position, the indoor blower operates
continuously.

TWO−STAGE COMPRESSOR

The two−stage scroll compressor operates much like the
standard scroll compressor. The two−stage compressor
steps between low capacity and high capacity as required
to meet cooling demand. The steps occur when gas is
bypassed through a vent port in the first suction pocket.
This bypassing of gas allows the compressor to operate at
low capacity if thermostat demand allows, creating a more
cost effective and efficient compressor.

Full capacity is achieved by blocking the vent port with a
slider ring. The slider ring (vent port cover) is controlled by
a 24VDC internal solenoid in the open position allowing low
capacity. When energized the internal solenoid closes the
slider ring, blocking the vent port and bringing the
compressor to full capacity. Stepping can occur during a
single thermostat demand as the motor runs continuously
while the compressor steps from low to full capacity.

FILTER DRIER

A filter drier is factory−installed in each XC16 unit to ensure
a clean, moisture−free system. Replacement driers are
available (refer to Lennox Repair Part Program).

HIGH PRESSURE SWITCH

XC16 units are equipped with a high pressure switch that is
located in the liquid line of the compressor. The switch
(SPST, manual reset, normally closed) removes power
from the compressor when liquid pressure rises above
factory setting at 590 + 10 psi.

LOW PRESSURE SWITCH

XC16 units are also equipped with a low pressure switch
that is located in the vapor line of the compressor. The
switch (SPST, auto−reset, normally closed) removes
power from the compressor when vapor line pressure
drops below factory setting at 40 + 5 psi.

Maintenance

Installation and service must be performed by a licensed
professional installer (or equivalent) or a service agency.
At the beginning of each cooling season, the system
should be checked as follows:

WARNING

Electric shock hazard. Can cause
injury or death. Before attempting to
perform any service or maintenance,
turn the electrical power to unit OFF at
disconnect switch(es). Unit may have
multiple power supplies.

OUTDOOR UNIT

1. Clean and inspect outdoor coil (may be flushed with a
water hose). Ensure power is off before cleaning.

2. Outdoor unit fan motor is pre−lubricated and sealed.
No further lubrication is needed.

3. Visually inspect all connecting lines, joints and coils for
evidence of oil leaks.

4. Check all wiring for loose connections.

5. Check for correct voltage at unit (unit operating).

6. Check amp draw on outdoor fan motor.

Unit Nameplate: _________ Actual: __________

7. Inspect drain holes in coil compartment base and
clean if necessary.

506101−01 07/09

Page 20

NOTE - If insufficient heating or cooling occurs, the unit
should be gauged and refrigerant charge should be
checked.

INDOOR COIL

1. Clean coil if necessary.

2. Check connecting lines, joints and coil for evidence of
oil leaks.

3. Check condensate line and clean if necessary.

INDOOR UNIT

1. Clean or change filters.

2. Blower motors are prelubricated and permanently
sealed. No more lubrication is needed.

3. Adjust blower speed for cooling. Measure the pressure
drop over the coil to determine the correct blower CFM.
Refer to the unit information service manual for pressure
drop tables and procedure.

4. Belt Drive Blowers − Check belt for wear and proper
tension.

5. Check all wiring for loose connections.

6. Check for correct voltage at unit. (blower operating)

7. Check amp draw on blower motor.
Unit Nameplate: _________ Actual: __________

TWO−STAGE COMPRESSOR CHECKS

Use the checklist procedure on page 23, to verify part-load
and full-load capacity operation of two-stage modulation
compressors.

IMPORTANT

This performance check is ONLY valid on systems
that have clean indoor and outdoor coils, proper
airflow over coils, and correct system refrigerant
charge. All components in the system must be
functioning proper to correctly perform compressor
modulation operational check. (Accurate
measurements are critical to this test as indoor
system loading and outdoor ambient can affect
variations between low and high capacity readings).

Tools Required

S Refrigeration gauge set
S Digital volt/amp meter
S Electronic temperature thermometer
S On-off toggle switch

Procedure

NOTE − Block outdoor coil to maintain a minimum of 375
psig during testing).

1. Turn main power OFF to outdoor unit.

2. Adjust room thermostat set point 5ºF above the room
temperature.

3. Remove control access panel. Install refrigeration
gauges on unit. Attach the amp meter to the common
(black wire) wire of the compressor harness. Attach
thermometer to discharge line as close as possible to
the compressor.

4. Turn toggle switch OFF and install switch in series with

Y2 wire from room thermostat.

5. Cycle main power ON.

6. Allow pressures and temperatures to stabilize before
taking measurements (may take up to 10 minutes).

7. Record all of the readings for the Y1 demand.

8. Close switch to energize Y2 demand. Verify power is
going to compressor solenoid.

9. Allow pressures and temperatures to stabilize before
taking any measured reading (this may take up to 10
minutes).

10. Record all of the readings with the Y1 and Y2 demand.

11. If temperatures and pressures change in the direction
noted in chart, the compressor is properly modulating
from low to high capacity. (If no amperage, pressures
or temperature readings change when this test is
performed, the compressor is not modulating between
low and high capacity and replacement is necessary).

12. After testing is complete, return unit to original set up.

Homeowner Information

In order to ensure peak performance, your system must be
properly maintained. Clogged filters and blocked airflow
prevent your unit from operating at its most efficient level.

1. Air FilterAsk your Lennox dealer to show you where

your indoor unit’s filter is located. It will be either at the
indoor unit (installed internal or external to the cabinet)
or behind a return air grille in the wall or ceiling. Check
the filter monthly and clean or replace it as needed.

2. Disposable FilterDisposable filters should be

replaced with a filter of the same type and size.

NOTE − If you are unsure about the filter required for your
system, call your Lennox dealer for assistance.

IMPORTANT

Turn off electrical power to the unit at the
disconnect switch before performing any
maintenance. The unit may have multiple power
supplies.

3. Reusable FilterMany indoor units are equipped

with reusable foam filters. Clean foam filters with a
mild soap and water solution; rinse thoroughly; allow
filter to dry completely before returning it to the unit or
grille.

NOTE − The filter and all access panels must be in place
any time the unit is in operation.

4. Electronic Air CleanerSome systems are

equipped with an electronic air cleaner, designed to
remove airborne particles from the air passing through
the cleaner. If your system is so equipped, ask your
dealer for maintenance instructions.

5. Indoor UnitThe indoor unit’s evaporator coil is

equipped with a drain pan to collect condensate
formed as your system removes humidity from the
inside air. Have your dealer show you the location of

Page 21

XC16 SERIES

the drain line and how to check for obstructions. This
would also apply to an auxiliary drain, if installed.

IMPORTANT

Sprinklers and soaker hoses should not be installed
where they could cause prolonged exposure to the
outdoor unit by treated water. Prolonged exposure
of the unit to treated water (i.e., sprinkler systems,
soakers, waste water, etc.) will corrode the surface
of steel and aluminum parts and diminish perfor­mance and longevity of the unit.

6. Outdoor UnitMake sure no obstructions restrict

airflow to the outdoor unit. Leaves, trash or shrubs
crowding the unit cause the outdoor unit to work harder
and use more energy. Keep shrubbery trimmed away
from the unit and periodically check for debris which
collects around the unit.

When removing debris from around the unit, be aware
of metal edges on parts and screws. Although special
care has been taken to keep exposed edges to a
minimum, physical contact with metal edges and
corners while applying excessive force or rapid motion
can result in personal injury.

Cleaning of the outdoor unit’s coil should be performed
by a trained service technician. Contact your dealer
and set up a schedule (preferably twice a year, but at
least once a year) to inspect and service your air
conditioning or heat pump system.

THERMOSTAT OPERATION

Thermostat operations vary from one thermostat to
another. The following provides general operation
procedures. Refer to the user’s information manual
provided with your thermostat for specific operation
details.

Temperature Setting Levers

Set the lever or dial to the desired temperature setpoints
for both heating and cooling. Avoid frequent temperature
adjustment; turning the unit offthen back onbefore
pressures can equalize will put stress on the unit’s
compressor.

Fan Switch

In AUTO or INT (intermittent) mode, the blower operates
only when the thermostat calls for heating or cooling. This
mode is generally preferred when humidity control is a
priority. The ON or CONT mode provides continuous
indoor blower operation, regardless of whether the
compressor or furnace is operating. This mode is required
when constant air circulation or filtering is desired.

System Switch

Set the system switch for heating, cooling or auto
operation. The auto mode allows the system to
automatically switch from heating mode to cooling mode to
maintain predetermined comfort settings.

Temperature Indicator

The temperature indicator displays the actual room
temperature.

PROGRAMMABLE THERMOSTATS

Your Lennox system may be controlled by a
programmable thermostat. These thermostats provide the
added feature of programmable time-of-day setpoints for
both heating and cooling. Refer to the user’s information
manual provided with your thermostat for detailed
programming and operation details.

Preservice Check

If your system fails to operate, check the following before
calling for service:

S Make sure all electrical disconnect switches are ON.
S Make sure the room thermostat Temperature Selector

and System Switch (Heat, Cool, Auto) are properly
set.

S If you discover any blown fuses or tripped circuit

breakers, call your Lennox dealer for assistance.

S Make sure unit access panels are in place.
S Make sure air filter is clean.
S Write down the unit model number and have it handy

before calling.

OPTIONAL ACCESSORIES

Refer to the Engineering Handbook for the latest optional
accessories available for XC16 series. Below is a list of
some of the optional accessories that may be available:

S Hard Start Kit
S Low Ambient Kit
S Timed Off Control
S Sound Cover
S Base Pan
S Suction Line Drier
S Crankcase Heater

506101−01 07/09

Page 22

Checklists

Two−Stage Modulation Compressors Field Operational Checklist

Unit Readings Y1 − First-Stage

COMPRESSOR

Voltage Same
Amperage Higher

OUTDOOR UNIT FAN MO­TOR

Amperage Same or Higher

TEMPERATURE

Ambient Same
Outdoor Coil Discharge Air Higher
Compressor Discharge Line Higher
Indoor Return Air Same
Indoor Coil Discharge Air Lower

PRESSURES

Suction (Vapor) Lower
Liquid Higher

Expected results during Y2

demand (Toggle switch On)

XC16 Start−Up and Performance Checklist

Customer Address
Indoor Unit Model Serial
Outdoor Unit Model Serial

Notes:

Y2 − Second-Stage

START UP CHECKS

Refrigerant Type:
First Stage: Rated Load Amps Actual Amps Rated Volts Actual Volts
Second Stage: Rated Load Amps Actual Amps Rated Volts Actual Volts
Outdoor Unit Fan Full Load Amps Actual Amps: Firsttage Second Stage

COOLING MODE

Suction Pressure: First Stage: Second Stage:

Liquid Pressure: First Stage: Second Stage:

Supply Air Temperature: First Stage: Second Stage:

Temperature: Ambient: Return Air:

System Refrigerant Charge (Refer to manufacturer’s information on unit or installation instructions for required sub­cooling and approach temperatures.)

Subcooling:

Saturated Condensing Temperature (A)

minus Liquid Line Temperature (B)

Approach:

Liquid Line Temperature (A)

minus Outdoor Air Temperature (B)

Indoor Coil Temperature Drop (18 to 22°F)

Return Air Temperature (A)

minus Supply Air Temperature (B)

A



A



A



B

B

B

SUBCOOLING

=

APPROACH

=

COIL TEMP DROP

=

Page 23

XC16 SERIES