Lennox XC21 User Manual

INSTALLATION

E2012 Lennox Industries Inc.

Dallas, Texas, USA

THIS MANUAL MUST BE LEFT WITH THE

HOMEOWNER FOR FUTURE REFERENCE

WARNING

The State of California has determined that this product
may contain or produce a chemical or chemicals, in very
low doses, which may cause serious illness or death. It
may also cause cancer, birth defects, or reproductive
harm.

General

This XC21 outdoor unit is designed for use with HFC−410A
refrigerant only. This unit must be installed with an ap­proved indoor unit. See the Lennox XC21 Product Specifi­cations bulletin (EHB) for approved indoor component
match ups.

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

INSTRUCTIONS

Dave Lennox Signature
Collection XC21 System

AIR CONDITIONERS
506923−01
7/2012

Supersedes 4/2012

WARNING

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

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

CAUTION

Before attempting to perform any service or mainte­nance, turn the electrical power to unit OFF at discon­nect switch.

NOTICE !

For more in−depth information, consult the Installa­tion and Service Procedures manual, available as
Corp.1007−L2 on DaveNet or through the Technical
Support department at 800−453−6669.

®

Litho U.S.A.

STEP 1 −− SETTING THE UNIT −− Clearances

CLEARANCE ON ALL SIDES  INCHES (MILLIMETERS)

6 (152)

CONTROL

PANEL ACCESS

LOCATION

24

(610)

30 (762)

12 (305)

36 (914)

MINIMUM CLEARANCE BETWEEN TWO UNITS

NOTES:

S Clearance to access panel must be 30

inches (762mm).

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

MINIMUM CLEARANCE

ABOVE UNIT

48 (1219)

REAR VIEW OF UNIT

FIGURE 1

7/2012 506923−01

Page 1

*2P72012* *P506923-01*

UNIT DIMENSIONS − INCHES (MM)

39−1/2
(1003)

DISCHARGE
AIR

SUCTIOn
LINE
INLET

LIQUID
LINE
INLET

ELECTRICAL

INLETS

47

(1194)

18−1/2

(470)

35−1/2

(902)

4−1/2
(114)

8 (203)

SIDE VIEW

UNIT SUPPORT
FEET

16−7/8

(429)

8−3/4
(222)

3−1/8

(79)

BASE WITH ELONGATED LEGS

STEP 1 −− SETTING THE UNIT (Continued)

−− Unit Placement

WARNING

To prevent personal injury, as well as damage to panels,
unit or structure, observe the following:

While installing or servicing this unit, carefully stow all
removed panels so that the panels will not cause injury
to personnel, objects or nearby structures. Also, take
care to store panels where they will not be subject to
damage (e.g., being bent or scratched).

While handling or stowing the panels, consider any
weather conditions (especially wind) that may cause
panels to be blown around and damaged.

30−3/4

(781)

1 (25)

26−7/8

(683)

3−3/4 (95)

4−5/8
(117)

ACCESS VIEW

NOTICE !

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

rubber roofing material may absorb oil, causing the
rubber to degrade. Failure to follow this notice
could result in damage to roof surface.

IMPORTANT !

Exhaust vents from dryers, water heaters and
furnaces should be directed away from the outdoor
unit. Prolonged exposure to exhaust gases and the
chemicals contained within them may cause
condensation to form on the steel cabinet and other
metal components of the outdoor unit. This will
diminish unit performance and longevity.

Page 2

PLACEMENT

INSTALL UNIT AWAY

FROM WINDOWS

STABILIZING UNIT ON UNEVEN SURFACES

#10 X 1/2" LONG

SELF−DRILLING

SHEET METAL

SCREWS

COIL

TWO 90_ ELBOWS INSTALLED IN LINE SET

WILL REDUCE LINE SET VIBRATION

FIGURE 2

SLAB MOUNTING

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

DISCHARGE AIR

MOUNTING
SLAB

GROUND LEVEL

FIGURE 3

ELEVATED SLAB MOUNTING USING FEET

EXTENDERS

2" (50.8MM) SCH 40

FEMALE THREADED

ADAPTER

2" (50.8MM)
SCH 40 MALE
THREADED
ADAPTER

LEG DETAIL

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.

BASE

STABILIZING BRACKET

(18 GAUGE METAL  2"

WIDTH; HEIGHT AS

REQUIRED)

#10 X 1−1/4" LONG

HEX HD SCREW AND

FLAT WASHER

Concrete slab  use two
plastic anchors (hole drill 1/4")

!

IMPORTANT !

CORNER POST

BASE PAN

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 any unit installed
on unstable and uneven surfaces.

FIGURE 5

STEP 2 −− REFRIGERANT PIPING −− Flush­ing Existing Line Set & Indoor Coil

Flush the existing line set per the following instruc-

tions. For more information, refer to the Installation
and Service Procedures manual available on Dave­Net. CAUTION − DO NOT attempt to flush and re−use ex-
isting line sets or indoor coil when the system con­tains contaminants (i.e., compressor burn out).

NOTE − When installing refrigerant lines longer than 50
feet, refer to the Refrigerant Piping Design and Fabrication
Guidelines manual available on DaveNet (Corp. 9351−L9),
or contact the Technical Support Department Product Ap­plication group for assistance.

NOTE − For new or replacement line set installation, refer
to Service and Application Note − Corp. 9112−L4 (C−91−4).

TABLE 1

REFRIGERANT LINE SET  INCHES (MM)

Models Liquid

Line

−024, −036
and−048

3/8 (10) 7/8 (22) L15 line set sizes are

Vapor/
Suction
Line

L15 Line Set

dependent on unit match up.
See XP21 Engineering
Handbook to determine
correct line set sizes.

FIGURE 4

−060 3/8 (10) 1−1/8 (29) Field Fabricated

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

Page 3

XC21 SERIES

IMPORTANT !

If this unit is being matched with an approved line
set or indoor unit coil that 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 sys­tem performance and capacity.

Failure to properly flush the system per this instruc­tion and the detailed Installation and Service Proce­dures manual will void the warranty.

WARNING

When using a high pressure gas such as
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).

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 fire
and/or an explosion, that could result in
property damage, personal injury or death.

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.

IMPORTANT !

Some scroll compressors have an internal vacuum
protector that will unload scrolls when suction pres­sure goes below 20 psig. A hissing sound will be
heard when the compressor is running unloaded.
Protector will reset when low pressure in system is
raised above 40 psig. DO NOT REPLACE COM­PRESSOR.

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.

CAUTION

As with any mechanical equipment, contact with sharp
sheet metal edges can result in personal injury. Take
care while handling this equipment.

Page 4

STEP 2 −− REFRIGERANT PIPING −− Removing Existing Indoor Metering Device

TYPICAL EXISTING FIXED ORIFICE

1A

DISTRIBUTOR

ASSEMBLY

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

2. Remove any shipping clamps from the liquid line and distributor as-

sembly.

3. Using two wrenches, disconnect liquid line from liquid line orifice hous-

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

4. Remove and discard fixed orifice, valve stem assembly (if present)

and Teflon® washer as illustrated above.

5. Use a field−provided fitting to temporarily reconnect the liquid line to the

indoor unit’s liquid line orifice housing.

(UNCASED COIL SHOWN)

DISTRIBUTOR TUBES

LIQUID LINE ORIFICE HOUSING

TEFLON® RING

FIXED ORIFICE

REMOVE AND DISCARD

WHITE TEFLON

(IF PRESENT)

®

SEAL

LIQUID LINE ASSEMBLY

(INCLUDES STRAINER)

REMOVAL PROCEDURE

OR

BRASS NUT

1B

TWO−PIECE PATCH PLATE

CONNECT GAUGES AND EQUIPMENT FOR
FLUSHING PROCEDURE

2

CYLINDER CONTAINING
CLEAN HCFC−22 TO BE
USED FOR FLUSHING
(Positioned to deliver liquid

A

refrigerant)

1

VAPOR LINE

SERVICE VALVE

EXISTING

INDOOR

UNIT

LIQUID LINE SERVICE

VALV E

RECOVERY

CYLINDER

VAPOR

LIQUID

OUTDOOR

B

NEW

UNIT

OPENED

C

D

RECOVERY MACHINE

1. HCFC−22 cylinder with clean refrigerant (positioned to deliver liquid

refrigerant) to the vapor service valve.

2. HCFC−22 gauge set (low side) to the liquid line valve.

3. HCFC−22 gauge set center port to inlet on the recovery machine with an

empty recovery tank connected to the gauge set.

4. Connect recovery tank to recovery machine per machine instructions.

GAUGE

MANIFOLD

LOW HIGH

CLOSED

TANK
RETURN

INLET

DISCHARGE

TYPICAL EXISTING EXPANSION VALVE REMOVAL
PROCEDURE (UNCASED COIL SHOWN)

ORIFICE

HOUSING

EQUALIZER
LINE

STUB END

TEFLON
RING

VAPOR

EXPANSION

VALV E

®

LIQUID LINE

ASSEMBLY WITH

BRASS NUT

LINE

TEFLON

RING

®

SENSING

(UNCASED COIL ONLY)

DISTRIBUTOR

TUBES

DISTRIBUTOR

ASSEMBLY

MALE EQUALIZER

LINE FITTING

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

2. Remove any shipping clamps from the liquid line and distributor

assembly.

3. Disconnect the equalizer line from the check expansion valve

equalizer line fitting on the vapor line.

4. Remove the vapor line sensing bulb.

5. Disconnect the liquid line from the check expansion valve at the liquid

line assembly.

6. Disconnect the check expansion valve from the liquid line orifice

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

7. Remove and discard check expansion valve and the two Teflon® rings.

8. Use a field−provided fitting to temporarily reconnect the liquid line to the

indoor unit’s liquid line orifice housing.

LIQUID LINE

SENSING BULB

FLUSHING LINE SET

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

3

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

1. 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.

2. Position the cylinder of clean HCFC−22 for delivery of liquid refrigerant

3. After all of the liquid refrigerant has been recovered, switch the

4. Close the valve on the inverted HCFC−22 drum and the gauge set

B

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.

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

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

LINE

LIQUID

LINE

FIGURE 6

Page 5

XC21 SERIES

STEP 2 −− REFRIGERANT PIPING −− Brazing Procedures

PIPING PANEL REMOVAL / PREPARING LINE SET

Remove piping panel to access service valves. Cut

1

ends of the refrigerant lines square (free from nicks or
dents) and debur the ends. The pipe must remain
round. Do not crimp end of the line.

CUT AND DEBUR

LINE SET SIZE MATCHES

SERVICE VALVE CONNECTION

SERVICE VALVE

COPPER TUBE

REDUCER

CONNECTION

STUB

REFRIGERANT LINE

LINE SET SIZE IS SMALLER

THAN CONNECTION

CAP AND CORE REMOVAL

Remove service cap and core from both the suction /

2

vapor and liquid line service ports.

SERVICE PORT CAP

SERVICE PORT
CORE

LIQUID LINE SERVICE VALVE

SERVICE PORT
CORE

SERVICE
PORT CAP

SUCTION / VAPOR LINE

DO NOT CRIMP SERVICE VALVE

CONNECTOR WHEN PIPE IS

SMALLER THAN CONNECTION

SERVICE VALVE

ATTACH THE MANIFOLD GAUGE SET FOR BRAZING
LIQUID AND SUCTION / VAPOR LINE SERVICE VALVES

3

A. Connect gauge set low pressure side to liquid line service valve (service port).
B. Connect gauge set center port to bottle of nitrogen with regulator.
C. With valve core removed from the suction / vapor line service port, nitrogen flow will have an exit point.

HIGHLOW

ATTACH

GAUGES

SUCTION / VAPOR SERVICE PORT MUST BE

OPEN AND SERVICE PORT CORE REMOVED

TO ALLOW EXIT POINT FOR NITROGEN FLOW

SUCTION / VAPOR

LINE

INDOOR

UNIT

LIQUID LINE

C

LIQUID LINE SERVICE

SUCTION /

VAPOR LINE

SERVICE

VALV E

VALV E

A

B

OUTDOOR

UNIT

NITROGEN

FIGURE 7

Page 6