Lennox HSXA12-018, HSXA12-024, HSXA12-030, HSXA12-048, HSXA12-036 Installation Instructions Manual

INSTALLATION

©2002 Lennox Industries Inc.

Dallas, Texas

HSXA12 Outdoor Unit

HSXA12 outdoor units use R410A which is an ozone
friendly HFC refrigerant. This unit must be installed with a
matching indoor coil and line set as outlined in the Lennox
Engineering Handbook. HSXA12 outdoor units are de­signed for use in expansion valve (TXV) and fixed orifice
systems. Refer to the Lennox Engineering Handbook for
expansion valve kits which must be ordered separately. A
filter dryer approved for use with R410A has been shipped
with the unit. This component must be installed prior to op­erating the unit. Failure to install the provided filter dryer
will void the warranty.

INSTRUCTIONS

HSXA12 Series Units

CONDENSING UNITS

504,540M
04/04

Supersedes 12/03

Table of Contents

HSXA12 Outdoor Unit 1. . . . . . . . . . . . . . . . . . . . . . . . . . .

Shipping And Packing List 1. . . . . . . . . . . . . . . . . . . . . . .

General Information 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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

Setting the Unit 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Electrical 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Refrigerant Piping 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Flushing Existing Line Set & Indoor Coil 5. . . . . . . . . . .

Refrigerant Metering Device 11. . . . . . . . . . . . . . . . . . . .

Manifold Gauge Set 11. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Service Valves 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Leak Testing 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Evacuation 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Start−up 14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Charging 14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

System Operation 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Maintenance 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Optional Accessories 18. . . . . . . . . . . . . . . . . . . . . . . . . .

HSXA12 Check Points 19. . . . . . . . . . . . . . . . . . . . . . . . .

RETAIN THESE INSTRUCTIONS

FOR FUTURE REFERENCE

General Information

Litho U.S.A.

Shipping and Packing List

1 − Assembled HSXA12 outdoor unit
1 − Liquid line filter drier (approved for use with R410A

systems)
1 − Fixed orifice refrigerant metering device
Check equipment for shipping damage. If you find any
damage, immediately contact the last carrier.

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 qualified installer or service
agency.

IMPORTANT

This unit must be matched with an indoor coil as
specified in Lennox’ Engineering Handbook. Coils
previously charged with R22 must be flushed.

04/04

*2P0404*

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

WARNING

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

Disturbing the insulation during 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
Dallas, TX 75379−9900

504,540M

Page 1

*P504540M*

Unit Dimensions − inches (mm)

HSXA12-018

HSXA12-036

INLET

AIR

INLET AIR

INLET AIR

Top View

C

INLET

AIR

LIQUID LINE

CONNECTION

OPTIONAL UNIT

STAND-OFF KIT (4)

(Field Installed)

COIL DRAIN OUTLETS

(Around perimeter of base)

VAPOR LINE

CONNECTION

4-3/8
(111 )

6-3/8
(162)

OUTDOOR

COIL FAN

COMPRESSOR

4-3/8
(111 )

COMPRESSOR

6-3/8
(162)

Top View Base Section

C

DISCHARGE AIR

4-3/8
(111 )

4-3/8
(111 )

4-3/8
(111 )

4-3/8
(111 )

Side View

HSXA12-018
HSXA12-024

HSXA12-030
HSXA12-036
HSXA12-042
HSXA12-048

HSXA12-060

B

A

ELECTRICAL

INLETS

VAPOR &

LIQUID LINE

CONNECTION

2-3/4 (70)

2 (51)

3/4

(19)

OPTIONAL UNIT

STAND-OFF KIT (4)

(Field Installed)

Model No. A B C

in. 25 24-1/4 24-1/4

mm 635 616 616

in. 33 32-1/4 24-1/4

mm 838 819 616

in. 29 28−1/4 28−1/4

mm 737 718 718

Side View

Page 2

Setting the Unit

CAUTION

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

CAUTION

Sharp sheet metal edges can cause injury. When
installing the unit, avoid accidental contact with
sharp edges.

Refer to unit dimensions for sizing mounting slab, plat­forms or supports. Refer to figure 1 for installation clear­ances.

Installation Clearances

36

(914 mm)

36

(914 mm)

36*

(914 mm)

*NOTE − A service clearance of 30" (762 mm) must be main­tained on one of the sides adjacent to the control box. Clear­ance to one of the other three sides must be 36" (914 mm).
Clearance to one of the remaining two sides may be 12" (304
mm) and the final side may be 6" (152 mm).

NOTE − A clearance of 24" (610 mm) must be maintained
between two units.
NOTE − 48" (1219 mm) clearance required on top
of unit. Maximum soffit overhang is 36" (914 mm).

Figure 1

Slab Mounting

When installing a unit at grade level, the top of the slab
should be high enough above the grade so that water from
higher ground will not collect around the unit. See figure 2.
Slab should have a slope tolerance away from the building
of 2 degrees or 2 inches per 5 feet (51 mm per 1524 mm).
Refer to roof mounting section for barrier construction if
unit must face prevailing winter winds.

Slab Mounting At Ground Level

structure

discharge air

36*

(914 mm)

Roof Mounting

Install unit at a minimum of 4 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.

Electrical

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.

WARNING

Unit must be grounded in accordance with national
and local codes.
ELECTRIC SHOCK HAZARD.
Can cause injury or death.

1 − Install line voltage power supply to unit from a properly

sized disconnect switch.

2 − Ground unit at unit disconnect switch or to an earth

ground.

NOTE − To facilitate conduit, a hole is in the bottom of
the control box. Connect conduit to the control box us
ing a proper conduit fitting.

NOTE − Units are approved for use only with copper
conductors.

24V, Class II circuit connections are made in the low
voltage junction box. Refer to figure 4 for field wiring
diagram.

NOTE − A complete unit wiring diagram is located in
side the unit control box cover.

3 − Install room thermostat (ordered separately) on an in-

side 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 effected
by sunlight, drafts or vibrations.

4 − Install low voltage wiring from outdoor to indoor unit

and from thermostat to indoor unit. See figure 3.

Mounting slab must slope
away from building.

Figure 2

ground level

Page 3

Thermostat Designations

Thermostat Indoor Unit

R

W1

power

heat

R

W

NOTE − see unit wiring diagram for

power supply connections.

Outdoor Unit

Y

G

C

NOTE − If the indoor unit is not equipped with blower relay. It must be field−provided and installed (P−8−3251 or equivalent).

cooling

indoor blower

common

Y

G

C

Y1 Outdoor Unit

C Outdoor Unit

Figure 3

Typical Field Wiring Diagram

*

*

*

*May be optional

Figure 4

Page 4

Refrigerant Piping

If the HSXA12 unit is being installed with an indoor coil and
line set, make the refrigerant connections as outlined in this
section. If an existing line set and/or indoor coil is going to
be used to complete the HSXA12 system, refer to this sec­tion, as well as the flushing section which follows.
Field refrigerant piping consists of liquid and vapor lines
from the outdoor unit (sweat connections) to the indoor coil
(flare or sweat connections). Use Lennox L15 (sweat, non­flare) series line sets as shown in table 1 or use field-fabri­cated refrigerant lines. Refer to Refrigerant Piping Guide
(Corp. 9351−L9) for proper size, type, and application of
field−fabricated lines. Valve sizes are also listed in table 1.

Refrigerant Line Connections

HSXA12 Matched with New Indoor Coil and Line Set
If the HSXA12 is being used with an existing indoor coil
which was equipped with a liquid line which served as
a metering device (RFCI), the liquid line must be re­placed prior to the installation of the HSXA12 unit.

If refrigerant lines are routed through a wall, seal and isolate
the opening so vibration is not transmitted to the building.

Table 1

Refrigerant Line Sets

Model

Valve Field Size

Connections

Liquid

Line

Vapor

Line

Recommended Line Set

Liquid

Line

Vapor

Line

L15

Line Sets

Installing Refrigerant Line

During the installation of any heat pump or a/c system, it is
important to properly isolate the refrigerant lines to prevent
unnecessary vibration. Line set contact with the structure
(wall, ceiling or floor) causes some objectionable noise
when vibration is translated into sound. As a result, more
energy or vibration can be expected. Closer attention to
line set isolation must be observed.

Following are some points to consider when placing and
installing a high−efficiency outdoor unit:

1- Placement − Be aware some localities are adopting

sound ordinances based on how noisy the unit is from
the adjacent property not at the original installation.
Install the unit as far as possible from the property line.
When possible, do not install the unit directly outside a
window. Glass has a very high level of sound transmis­sion.

2- Line Set Isolation − The following illustrations demon-

strate procedures which ensure proper refrigerant line
set isolation. Figure 5 shows how to install line sets on
vertical runs. Figure 6 shows how to install line sets on
horizontal runs. Figure 7 shows how to make a transition
from horizontal to vertical. Finally, figure 8 shows how to
place the outdoor unit and line set.

L15−26

15 ft. − 50 ft.

(4.6 m − 15 m)

L15−41

15 ft. − 50 ft.

(4.6 m − 15 m)

L15−65

15 ft. − 50 ft.

(4.6 m − 15 m)

Field

Fabricated

−018

024

−030

−036

−042

−048

−060

3/8 in.

(10 mm)

3/8 in.

(10 mm)

3/8 in.

(10 mm)

3/8 in.

(10 mm)

5/8 in.

(16 mm)

3/4 in.

(19 mm)

7/8 in.

(22 mm)

1−1/8 in.
(29 mm)

3/8 in.

(10 mm)

3/8 in.

(10 mm)

3/8 in.

(10 mm)

3/8 in.

(10 mm)

5/8 in.

(19 mm)

3/4 in.

(19 mm)

7/8 in.

(22 mm)

1−1/8 in.
(29 mm)

NOTE − Units are designed for line sets of up to fifty feet (15
m). For applications longer than fifty feet, consult the Len­nox Refrigerant Piping Guide (Corp. 9351−L9). Select line
set diameters from table 1 to ensure that oil returns to the
compressor.

Page 5

Refrigerant Line Sets

How To Install Vertical Runs

(new construction shown)

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

Outside Wall

Wood Block

Between Studs

Liquid Line

Vapor Line

(wrapped with Armaflex)

Outside Wall

IMPORTANT - Refrigerant

lines must not contact wall.

Liquid LineVapor Line

Wire Tie

Inside Wall

Strap

Sleeve

Wire Tie

Wood Block

Wire Tie

Caulk

PVC Pipe

Fiberglass

Insulation

IMPORTANT - Refrigerant

lines must not contact

structure.

Strap

Sleeve

Figure 5

Page 6

Installing Horizontal Runs

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

Floor Joist or

Roof Rafter

Refrigerant Line Sets:

Wire Tie

(around vapor line only)

8 feet

Tape or Wire Tie

8 feet

Strapping Material (around vapor line only)

Tape or Wire Tie

Metal Sleeve

Floor Joist or Roof Rafter

Strap the vapor line to the joist or rafter at 8 ft.
intervals then strap the liquid line to the vapor line.

Figure 6

Page 7

Refrigerant Line Sets:

Transition From Vertical To Horizontal

Anchored Heavy

Nylon Wire Tie

Wall
Stud

Metal

Sleeve

Vapor Line

Wrapped in

Armaflex

Strap Liquid Line

To Vapor Line

Liquid Line

Figure 7

Automotive

Muffler-Type

Hanger

Wall
Stud

Metal

Sleeve

Strap Liquid Line

To Vapor Line

Liquid Line

Vapor Line

Wrapped in

Armaflex

Outside Unit Placement and Installation

Install unit away from windows.

Two 90° elbows
installed in line set
will reduce line set
vibration.

Figure 8

Page 8

WARNING

Polyol ester (POE) oils used with R410A 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 ser-

vice valve stub caps until you are ready to make

connections.

Brazing Connection Procedure

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.

2 − Before making line set connections, use dry nitrogen to

purge the refrigerant piping. This will help to prevent
oxidation and the introduction of moisture into the sys­tem.

3 − Use silver alloy brazing rods (5 or 6 percent minimum

silver alloy for copper−to−copper brazing or 45 percent
silver alloy for copper−to−brass or copper−to−steel braz­ing) which are rated for use with R410A refrigerant.
Wrap a wet cloth around the valve body and the copper
tube stub. Remove light maroon washers from service
valves and shield light maroon stickers in order to pro­tect them during brazing. Braze the line set to the ser­vice valve.

4 − Wrap a wet cloth around the valve body and copper

tube stub to protect it from heat damage during braz­ing. Wrap another wet cloth underneath the valve body
to protect the base paint.

Quench the joints with a wet cloth to prevent possible
heat damage to the valve core and opening port.

NOTE − The tube end must stay bottomed in the fitting
during final assembly to ensure proper seating, sealing
and rigidity.

5 − Install the provided fixed orifice (or thermal expan-

sion valve which is sold separately and approved
for use with R410A refrigerant) in the liquid line at the

indoor coil.

6 − Install the provided filter drier (approved for use with

R410A refrigerant) in the liquid line as close as pos­sible to the expansion device. Do not leave the filter

drier uncapped for more than 10 to 15 minutes
prior to brazing, evacuation, and leak testing.
Polyol ester oils used in this system absorb mois­ture quickly. Failure to install the filter drier will
void the warranty.

Flushing Existing Line Set & Indoor Coil

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. App­plication of a brazing torch while pres­surized may result in ignition of the
refrigerant and oil mixture − check the
high and low pressures before unbra­zing.

IMPORTANT

If this unit is being matched with an approved line
set or indoor 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 R410A 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.

CAUTION

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

Required Equipment

You will need the following equipment in order to flush the
existing line set and indoor coil: two clean R22 recovery
bottles, an oilless recovery machine that has a pump down
feature, and two sets of gauges (one for use with R22 and
one for use with the R410A).

Flushing Procedure

1 − Remove existing R22 refrigerant using the appropri-

ate procedure below.

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 R22 refrigerant
to flush the system − Disconnect all power to the ex-

isting outdoor unit. Connect to the existing unit, a

Page 9

clean recovery cylinder and the recovery machine
according to the instructions provided with the recov­ery machine. Remove all R22 refrigerant from the ex­isting system. Refer to gauges after shutdown to con­firm that the entire system is completely void of refrig­erant. Disconnect the liquid and vapor lines from the
existing outdoor unit.

If the existing outdoor unit is equipped with
manual shut−off valves AND you plan to use NEW
R22 refrigerant to flush the system − Start the exist-

ing R22 system in the cooling mode and close the liq­uid line valve. Pump all of the existing R22 refrigerant
back into the outdoor unit. (It may be necessary to by­pass the low pressure switches to ensure complete
refrigerant evacuation.) When the low side system
pressures reach 0 psig, close the vapor line valve.
Disconnect all power to the existing outdoor unit. Re­fer to gauges after shutdown to confirm that the
valves are not allowing refrigerant to flow back into
the low side of the system. Disconnect the liquid and
vapor lines from the existing outdoor unit.

Flushing Connections

2 − Remove the existing outdoor unit. Set the new R410A

unit and follow the brazing connection procedure
which begins on the previous page to make line set
connections. DO NOT install the provided fixed ori-

fice yet.

Make low voltage and line voltage connections to the
new outdoor unit. DO NOT turn on power to the unit

or open the outdoor unit service valves at this
time.

3 − Remove the existing refrigerant flow control orifice or

thermal expansion valve before continuing with flush­ing procedures. The existing devices are not ap­proved for use with R410A refrigerant and may pre­vent proper flushing. Use a field−provided fitting to re­connect the lines.

IMPORTANT

The line set and indoor 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.

Existing

Indoor Coil

RECOVERY CYLINDER

Inverted R22 Cylinder

(Contains clean R22 to

be used for flushing)

Existing Vapor Line

Existing Liquid Line

Vapor Line

Service Valve

Liquid Line

Service Valve

Tank Return

Inlet

Discharge

RECOVERY MACHINE

Figure 9

Low

Pressure

HSXA12

Unit

NOTE − The inverted R22 cylin­der must contain at least the
same amount of refrigerant as
was recovered from the existing
system.

GAUGE MANIFOLD

High

Pressure

ClosedOpened

Page 10

4 − Remove the pressure tap valve cores from the

HSXA12 unit’s service valves. Connect an R22 cylin­der with clean refrigerant to the vapor service valve.
Connect the R22 gauge set to the liquid line valve and
connect a recovery machine with an empty recovery
tank to the gauge set.

5 − 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 coil.

6 − Invert the cylinder of clean R22 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 coil
before it enters the recovery machine.

7 − After all of the liquid refrigerant has been recovered,

switch the recovery machine to vapor recovery so that
all of the R22 vapor is recovered. Allow the recovery
machine to pull a vacuum on the system.

NOTE − A single system flush should remove all of the
mineral oil from the existing refrigerant lines and in­door coil. A second flushing may be done (using clean
refrigerant) if insufficient amounts of mineral oil were
removed during the first flush. Each time the system

is flushed, you must allow the recovery machine
to pull a vacuum on the system at the end of the
procedure.

8 − Close the valve on the inverted R22 drum and the

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

9 − Use nitrogen to break the vacuum on the refrigerant

lines and indoor coil before removing the recovery ma­chine, gauges and R22 refrigerant drum. Reinstall
pressure tap valve cores into HSXA12 service valves.

10 −Install the provided fixed orifice in the liquid line at the

indoor coil.

Refrigerant Metering Device

may not be appropriately sized. Refer to the Engineering
Handbook for specific orifice information.

Table 2

Fixed Orifice Drill Sizes

Unit Fixed Orifice Part # Drill Size

HSXA12−018 29M88 .05

HSXA12−024 42J43 .063

HSXA12−030 42J43 .063

HSXA12−036 42J47 .071

HSXA12−042 42J51 .078

HSXA12−048 29M93 .081

HSXA12−060 42J57 .090

Install the fixed orifice as shown in figure 10. Do not twist
the cap tubes when loosening the seal nut from the orifice
housing. Use a wrench to back up the distributor.

Metering Device Installation

orifice

(factory−installed)

distributor

valve OR orifice

o−ring

expansion
valve (opt.)

o−ring

strainer

liquid line

stub

Figure 10

Expansion Valve Systems

Expansion valves equipped with Chatleff type fittings are
available from Lennox. Refer to the Engineering Handbook
for expansion valves for use with specific match−ups.

If you install an expansion valve with an indoor coil that
includes a fixed orifice, remove the orifice before the
expansion valve is installed.

HSXA12 units are applicable to either fixed orifice or an
expansion valve system. See the indoor coil installation
instructions and the Lennox Engineering Handbook for
approved TXV and fixed orifice match−ups and application
information. Table 1 lists the unit liquid and vapor line sizes
and corresponding line sets.

Fixed Orifice Systems

HSXA12 units are shipped with a fixed orifice refrigerant
metering device. Replace the existing indoor unit fixed ori­fice with the orifice supplied with the outdoor unit. Place the
supplied fixed orifice sticker on the indoor cabinet after
installation. See table 2 for the fixed orifice size for each
unit. In nonstandard applications, the provided fixed orifice

IMPORTANT

Failure to remove a fixed orifice when installing an
expansion valve to the indoor coil will result in im­proper operation and damage to the system.

Manifold Gauge Set

Manifold gauge sets used with systems charged with
R410A refrigerant 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.

Page 11

Service Valves

The liquid line and vapor line service valves (figures 11 and

12) and gauge ports are used for leak testing, evacuating,
charging and checking charge. See table 3 for torque re­quirements.

Each valve is equipped with a service port which has a fac­tory−installed Schrader valve. A service port cap protects
the Schrader valve from contamination and serves as the
primary leak seal.

Table 3

Torque Requirements

Part Recommended Torque

Service valve cap 8 ft.− lb. 11 N M

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 N M

To Access Schrader Port:

1 − Remove service port cap with an adjustable wrench.
2 − Connect gauge to the service port.
3 − When testing is completed, replace service port cap.

Tighten finger tight, then tighten an additional 1/6 turn.

To Open Service Valve:

1 − Remove stem cap with an adjustable wrench.
2 − Use a service wrench with a hex−head extension to

back the stem out counterclockwise as far as it will go.

NOTE − Use a 3/16" hex head extension for liquid line
sizes or a 5/16" extension for vapor line sizes.

3 − Replace the stem cap. Tighten finger tight, then tighten

an additional 1/6 turn.

To Close Service Valve:

1 − Remove the stem cap with an adjustable wrench.
2 − Use a service wrench with a hex−head extension to

turn the stem clockwise to seat the valve. Tighten it
firmly.

NOTE − Use a 3/16" hex head extension for liquid line
sizes or a 5/16" extension for vapor line sizes.

3 − Replace the stem cap. Tighten finger tight, then tighten

an additional 1/6 turn.

Service Valve

(Valve Closed)

service

port

to outdoor coil

service

port cap

Schrader valve open

to line set when valve is

closed (front seated)

wrench here

(valve front seated)

stem cap

insert hex

to indoor coil

Service Valve

insert hex

wrench here

to outdoor coil

service port

cap

(Valve Open)

service

port

Schrader

valve

stem cap

to indoor coil

Figure 11

Vapor Line (Ball Type) Service Valve

Vapor line service valves function the same way as the oth-

er valves; the difference is in the construction. These

valves are not rebuildable. If a valve has failed, you must

replace it. A ball valve is illustrated in figure 12.

The ball valve is equipped with a service port with a factory−

installed Schrader valve. A service port cap protects the

Schrader valve from contamination and assures a leak−

free seal.

Page 12

Ball Valve (Valve Open)

Use Adjustable Wrench

To open: rotate Stem Counter-clockwise 90°.

To close: rotate Stem Clockwise 90°.

stem cap

to outdoor coil

stem

ball

(shown open)

to indoor coil

service port

cap

service port

Schrader valve

Figure 12

Leak Testing

After the line set has been connected to the indoor and
outdoor units, check the line set connections and indoor
unit for leaks.

WARNING

2 − With both manifold valves closed, connect the cylinder

of R410A refrigerant. Open the valve on the R410A cyl­inder (vapor only).

3 − Open the high pressure side of the manifold to allow

R410A into the line set and indoor unit. Weigh in a trace
amount of R410A. [A trace amount is a maximum of 2

ounces (57 g) refrigerant or 3 pounds (31 kPa) pres­sure]. Close the valve on the R410A cylinder and the

valve on the high pressure side of the manifold gauge
set. Disconnect R410A cylinder.

4 − Connect a cylinder of nitrogen with a pressure regulat-

ing valve to the center port of the manifold gauge set.

5 − Connect the manifold gauge set high pressure hose to

the vapor valve service port. (Normally, the high pres-

sure hose is connected to the liquid line port; however,
connecting it to the vapor port better protects the man­ifold gauge set from high pressure damage.)

6 − Adjust 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.

7 − After a few minutes, open a refrigerant port to ensure

the refrigerant you added is adequate to be detected.
(Amounts of refrigerant will vary with line lengths.)
Check all joints for leaks. Purge nitrogen and R410A
mixture. Correct any leaks and recheck.

Refrigerant can be harmful if it is inhaled. Refriger-

ant must be used and recovered responsibly.

Failure to follow this warning may result in personal

injury or death.

WARNING

Danger of explosion: Can cause
equipment damage, injury or death.
Never use oxygen to pressurize a re­frigeration or air conditioning system.
Oxygen will explode on contact with
oil and could cause personal injury.

WARNING

Danger of explosion: Can cause equipment damage,

injury or death. 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).

Using an Electronic Leak Detector

1 − Connect a cylinder of R410A to the center port of the

manifold gauge set.

IMPORTANT

Leak detector must be capable of sensing HFC re­frigerant.

Evacuation

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

IMPORTANT

Use a thermocouple or thermistor electronic vacuum
gauge that is calibrated in microns. Use an instrument
that reads from 50 microns to at least 10,000 microns.

1 − Connect manifold gauge set to the service valve ports

as follows:
 low pressure gauge to vapor line service valve

 high pressure gauge to liquid line service valve

2 − Connect micron gauge.

Page 13

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). 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 absolute pressure.
A rapid rise in pressure 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 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.

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.

7 − Shut off the nitrogen cylinder and remove the manifold

gauge hose from the cylinder. Open the manifold
gauge valves to release the 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 R410A
refrigerant. Open the manifold gauge valves to break
the vacuum from 1 to 2 psig positive pressure in the line
set and indoor unit. Close manifold gauge valves and
shut off the R410A cylinder and remove the manifold
gauge set.

Start−Up

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 frozen bearings or binding.

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

connections.

3 − After evacuation is complete, open the liquid line and

vapor 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 pow-

er 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.

Charging

This system is charged with R410A refrigerant which oper­ates at much higher pressures than R22. The provided liq­uid line filter drier is approved for use with R410A. Do not
replace it with components designed for use with R22. This
unit is NOT approved for use with coils which use capillary
tubes as a refrigerant metering device.

Factory Charge

Units are factory charged with the amount of R410A refrig­erant indicated on the unit rating plate. This charge is
based on a matching indoor coil and outdoor coil with 15 ft.
(4.6 m) line set. For varying lengths of line set, refer to table
4 for refrigerant charge adjustment.

Table 4

Liquid Line Set

Diameter

3/8 in.

(10 mm)

*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.

Oz. per 5 ft. (grams per 1.5 m) adjust

from 15 ft. (4.6 m) line set*

3 ounces per 5 feet

(85g per 1.5 m)

IMPORTANT

Mineral oils are not compatible with R410A. If oil
must be added, it must be a polyol ester oil.

Page 14

The compressor is charged with sufficient polyol ester
oil for line set lengths up to 50 feet (15.2 m). If oil must
be added to the compressor in the field, Copeland has
approved Mobil EALt Arctic 22CC and ICI EMKA­RATEt RL32CF.

Units 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 leaks, if possible.

2 − Evacuate the system to remove as much of the mois-

ture as possible.

3 − Use nitrogen to break the vacuum and install the pro-

vided filter drier in the system.

4 − Evacuate the system again. Then, weigh the appropri-

ate amount of R410A refrigerant (listed on unit name­plate) into the system.

5 − Monitor the system to determine the amount of mois-

ture remaining in the oil. Use test kit 10N46 to verify
that the moisture content is within the kit’s dry color
range. 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.

Checking Charge

The outdoor unit should be charged during warm weather.
However, applications arise in which charging must occur
in the colder months. The method of charging is deter-

mined by the unit’s refrigerant metering device and the
outdoor ambient temperature.

Measure the liquid line temperature and the outdoor ambi­ent temperature as outlined below:

1 − Connect the manifold gauge set to the service valves:

 low pressure gauge to vapor valve service port
 high pressure gauge to liquid valve service port

Close manifold gauge set valves. Connect the center
manifold hose to an upright cylinder of R410A .

2 − Set the room thermostat to call for heat. This will create

the necessary load for properly charging the system in
the cooling cycle.

3 − Use a digital thermometer to record the outdoor ambi-

ent temperature.

4 − When the heating demand has been satisfied, switch

the thermostat to cooling mode with a set point of 68F
(20C). When pressures have stabilized, use a digital
thermometer to record the liquid line temperature.

5 − The outdoor temperature will determine which charg-

ing method to use. Proceed with the appropriate charg­ing procedure.

Weighing in the Charge Fixed Orifice or

TXV Systems – Outdoor Temp. < 65F (18C)

If the system is void of refrigerant, or if the outdoor ambient
temperature is cool, the refrigerant charge should be
weighed into the unit. Do this after any leaks have been re­paired.

1 − Recover the refrigerant from the unit.

2 − Conduct a leak check, then evacuate as previously

outlined.

3 − Weigh in the unit nameplate charge.

If weighing facilities are not available or if you are charging
the unit during warm weather, follow one of the other proce­dures outlined below.

Charging Using the Subcooling Method

Fixed Orifice Systems

Outdoor Temp. >

If you charge a fixed orifice system when the outdoor ambi­ent is 65F (18C) or above, use the subcooling method to
charge the unit.

1 − With the manifold gauge hose still on the liquid service

port and the unit operating stably, use a digital ther-

mometer to record the liquid line temperature.
2 − At the same time, record the liquid line pressure reading.
3 − Use a temperature/pressure chart for R410A to deter-

mine the saturation temperature for the liquid line pres-

sure reading. See table 5.

4 − Subtract the liquid line temperature from the saturation

temperature (according to the chart) to determine sub-

cooling. (Saturation temperature − Liquid line tem-

perature = Subcooling)

5 − Compare the subcooling value with those in table 6. If

subcooling is greater than shown, recover some refrig-

erant. If subcooling is less than shown, add some re-

frigerant.

65F (18C))

Page 15

Table 5

Outdoor

R410A Temperature/Pressure Chart

Temperature°FPressure

Psig

32 100.8 63 178.5 94 290.8 125 445.9

33 102.9 64 181.6 95 295.1 126 451.8

34 105.0 65 184.3 96 299.4 127 457.6

35 107.1 66 187.7 97 303.8 128 463.5

36 109.2 67 190.9 98 308.2 129 469.5

37 111.4 68 194.1 99 312.7 130 475.6

38 113.6 69 197.3 100 317.2 131 481.6

39 115.8 70 200.6 101 321.8 132 487.8

40 118.0 71 203.9 102 326.4 133 494.0

41 120.3 72 207.2 103 331.0 134 500.2

42 122.6 73 210.6 104 335.7 135 506.5

43 125.0 74 214.0 105 340.5 136 512.9

44 127.3 75 217.4 106 345.3 137 519.3

45 129.7 76 220.9 107 350.1 138 525.8

46 132.2 77 224.4 108 355.0 139 532.4

47 134.6 78 228.0 109 360.0 140 539.0

48 137.1 79 231.6 110 365.0 141 545.6

49 139.6 80 235.3 111 370.0 142 552.3

50 142.2 81 239.0 11 2 375.1 143 559.1

51 144.8 82 242.7 11 3 380.2 144 565.9

52 147.4 83 246.5 11 4 385.4 145 572.8

53 150.1 84 250.3 11 5 390.7 146 579.8

54 152.8 85 254.1 11 6 396.0 147 586.8

55 155.5 86 258.0 11 7 401.3 148 593.8

56 158.2 87 262.0 11 8 406.7 149 601.0

57 161.0 88 266.0 11 9 412.2 150 608.1

58 163.9 89 270.0 120 417.7 151 615.4

59 166.7 90 274.1 121 423.2 152 622.7

60 169.6 91 278.2 122 428.8 153 630.1

61 172.6 92 282.3 123 434.5 154 637.5

62 195.5 93 286.5 124 440.2 155 645.0

Temperature°FPressure

Psig

Temperature°FPressure

Psig

Temperature°FPressure

Psig

Subcooling Values for Fixed Orifice Systems

Outdoor

Temp. °F (°C)

65 (18) 13 (7.2) 13 (7.2) 16 (8.9) 12 (6.7) 11 (6.4) 14 (7.8) 13 (7.2)
70 (21) 12 (6.7) 11 (6.1) 15 (8.3) 11 (6.1) 10 (5.6) 13 (7.2) 12 (6.7)
75 (24) 11 (6.1) 10 (5.6) 14 (7.8) 10 (5.6) 9 (5) 12 (6.7) 11 (6.1)
80 (27) 9 (5) 9 (5) 13 (7.2) 9 (5) 8 (4.5) 11 (6.1) 10 (5.6)
85 (29) 8 (4.5) 7 (3.9) 12 (6.7) 8 (4.5) 7 (3.9) 10 (5.6) 10 (5.6)
90 (32) 6 (3.3) 6 (3.3) 10 (5.6) 7 (3.9) 6 (3.3) 9 (5) 9 (5)

95 (35) 5 (2.8) 5 (2.8) 9 (5) 6 (3.3) 6 (3.3) 8 (4.5) 8 (4.5)
100 (38) 5 (2.8) 4 (2.2) 8 (4.5) 5 (2.8) 5 (2.8) 7 (3.9) 7 (3.9)
105 (41) 4 (2.2) 4 (2.2) 7 (3.9) 4 (2.2) 4 (2.2) 7 (3.9) 6 (3.3)
110 (43) 3 (1.7) 3 (1.7) 6 (3.3) 4 (2.2) 3 (1.7) 6 (3.3) 6 (3.3)
115 (45) 2 (1.1) 3 (1.7) 5 (2.8) 3 (1.7) 3 (1.7) 6 (3.3) 5 (2.8)

−018 −024 −030 −036 −042 −048 −060

Table 6

Liquid Subcooling [± 1°F (.6°C)]

Page 16

Approach Method and

Mode

Normal Operating Pressures

TXV Systems – Outdoor Temp. >

The following procedure is intended as a general guide and
is for use on expansion valve systems only. For best results,
indoor temperature should be 70°F (21°C) to 80°F (26°C).
Monitor system pressures while charging.

1 − Record outdoor ambient temperature using a digital

thermometer.

2 − Attach high pressure gauge set and operate unit for

several minutes to allow system pressures to stabilize.

3 − Compare stabilized pressures with those provided in

table 8, Normal Operating Pressures." Minor varia­tions in these pressures may be expected due to differ­ences in installations. Significant differences could
mean that the system is not properly charged or that a
problem exists with some component in the system.
Pressures higher than those listed indicate that the
system is overcharged. Pressures lower than those
listed indicate that the system is undercharged. Verify
adjusted charge using the approach method.

Approach Method

4 − Use the same digital thermometer you used to check

the outdoor ambient temperature to check the liquid
line temperature.

5 − The difference between the ambient and liquid temper-

atures should match values given in table 7. If the val­ues don’t agree with the those in table 7, add refriger­ant to lower the approach temperature, or recover re-

65F (18C)

frigerant from the system to increase the approach
temperature.
Be aware of the R410A refrigerant cylinder. It will be
rose−colored. Refrigerant should be added through the
vapor valve in the liquid state. Some R410A cylinders

are equipped with a dip tube which allows you to
draw liquid refrigerant from the bottom of the cylin­der without turning the cylinder upside−down. The
cylinder will be marked if it is equipped with a dip
tube.

Table 7

HSXA12 Approach Values

Model No.

−018 10 (5.6)

−024 12 (6.7)

−030 13 (7.2)

−036 12 (6.7)

−042 11 (6.1)

−048 13 (7.2)

−060 14 (7.8)

Approach Temperature

Liquid Line −

Outdoor Ambient °F (°C)

IMPORTANT

Use table 8 to perform maintenance checks. Table 8
is not a procedure for charging the system. Minor
variations in these pressures may be due to 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.

Table 8

Normal Operating Pressures In psig (liquid +/− 10 and vapor +/− 5 PSIG)*

Out. Coil

Mode

fixed
orifice

TXV

Entering Air

Temp.

°F (°C)

65 (18.3) 238 123 261 131 261 128 268 130 254 121 270 124 280 121

75 (23.9) 275 131 300 135 300 133 308 134 296 128 311 130 332 126

85 (29.4) 317 136 343 139 343 138 351 138 340 133 356 134 379 130

95 (35.0) 362 141 391 143 387 141 398 142 389 138 404 139 427 135

105 (40.6) 410 144 441 147 434 145 447 146 440 142 456 143 479 140

65 (18.3) 234 133 256 134 256 137 264 135 256 124 269 131 262 121

75 (23.9) 270 135 298 137 296 139 305 138 296 127 312 133 304 127

85 (29.4) 312 137 344 140 339 141 349 139 341 133 357 135 349 132

95 (35.0) 361 138 394 142 384 144 396 140 389 136 406 137 397 136

105 (40.6) 409 141 448 143 432 146 446 143 440 140 460 140 449 140

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

−018 −024 −030 −036 −042 −048 −060

LIQ SUC LIQ SUC LIQ SUC LIQ SUC LIQ SUC LIQ SUC LIQ SUC

Page 17

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.

Compressor Time Delay (TD1)

A compressor time delay is used to prevent compressor
short cycling and to prevent the compressor from running
backwards. When there is demand for a cooling cycle, the
control delays compressor operation for about 5 minutes (+
2 minutes). Do not bypass the control.

High Pressure Switch

HSXA12 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 discharge pressure rises
above factory setting at 640 + 10 psi.

Low Pressure Switch

HSXA12 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.

Filter Drier

A filter drier is shipped with each HSXA12 unit. The filter
drier must be field installed in the liquid line between the
liquid line service valve and the expansion valve. This fil-

ter drier must be installed to ensure a clean, moisture−
free system. Failure to install the filter drier will void
the warranty. A replacement filter drier is available as

from Lennox.

1 − Clean and inspect the outdoor coil. The coil may be

flushed with a water hose. Ensure the power is turned
off before you clean the coil.

2 − Outdoor fan motor is prelubricated and sealed. No fur-

ther lubrication is needed.

3 − Visually inspect connecting lines and coils for evidence

of oil leaks.

4 − Check wiring for loose connections.

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

6 − Check amp−draw outdoor fan motor.

Unit nameplate _________ Actual ____________ .

NOTE − If owner complains of insufficient cooling, the
unit should be gauged and refrigerant charge
checked. Refer to section on refrigerant charging in
this instruction.

Indoor Coil

1 − Clean coil, if necessary.

2 − Check connecting lines and coils for evidence of oil

leaks.

3 − Check condensate line and clean, if necessary.

Indoor Unit

1 − Clean or change filters.

2 − 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.

3 − Belt Drive Blowers − Check belt for wear and proper

tension.

4 − Check all wiring for loose connections

5 − Check for correct voltage at unit (blower operating).
6 − Check amp−draw on blower motor

Unit nameplate_________ Actual ____________.

Maintenance

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.

Maintenance and service must be performed by a qualified
installer or service agency. At the beginning of each cooling
season, the system should be checked as follows:

Optional Accessories

Refer to the Engineering Handbook for optional accesso­ries that may apply to this unit. The following may or may
not apply:

 Loss of Charge Kit
 High Pressure Switch Kit
 Compressor Monitor
 Compressor Crankcase Heater
 Hail Guards
 Mounting Bases
 Timed Off Control
 Stand−off Kit
 Sound Cover
 Low Ambient Kit

Page 18

HSXA12 Check Points

Job Name

Job Location

Installer

Unit Model No.

Nameplate Voltage

Rated Load Ampacity

Maximum Fuse or Circuit Breaker

Electrical Connections Tight?

Indoor Blower RPM

Discharge Pressure

Refrigerant Lines:

Service Valves Fully Opened?

Voltage With Compressor Operating

Leak Checked?

Start−up and Performance Check List

Job No.

City

City

Serial No.

Compressor

Indoor Filter Clean?

S.P. Drop Over Indoor (Dry)

Vapor Pressure

Properly Insulated?

Service Valve Caps Tight?

Calibrated? Properly Set?

Date

State

State

Service Technician

Outdoor Fan

Supply Voltage (Unit Off)

Outdoor Coil Entering Air Temp.

Refrigerant Charge Checked?

Outdoor Fan Checked?

Thermostat

Level?

Page 19