Rheem A18AZ Series User manual

VARIABLE SPEED R-410A
HEAT PUMP/AIR CONDITIONER
OUTDOOR UNITS
92-104921-27-01 ( / ) Printed in USA
[ ] indicates metric conversions.
Do not destroy this manual.
Please read carefully and
keep in a safe place for future
reference by a serviceman.
WARNING
THESE INSTRUCTIONS
ARE INTENDED AS AN AID
TO QUALIFIED, LICENSED
SERVICE PERSONNEL FOR
PROPER INSTALLATION,
ADJUSTMENT, AND
OPERATION OF THIS UNIT.
READ THESE INSTRUCTIONS
THOROUGHLY BEFORE
ATTEMPTING INSTALLATION
OR OPERATION. FAILURE
TO FOLLOW THESE
INSTRUCTIONS MAY
RESULT IN IMPROPER
INSTALLATION,
ADJUSTMENT, SERVICE,
OR MAINTENANCE
POSSIBLY RESULTING IN
FIRE, ELECTRICAL SHOCK,
PROPERTY DAMAGE,
PERSONAL INJURY, OR
DEATH.
(-)A18AZ & (-)P18AZ (18 SEER2)
EQUIPPED WITH ECONET™
COMMUNICATIONS
WARNING:
RECOGNIZE THIS SYMBOL
AS AN INDICATION OF
IMPORTANT SAFETY
INFORMATION
ISO 9001:2015
Enabled
INSTALLATION INSTRUCTIONS

Contents
2
Contents
1.0 IMPORTANT SAFETY INFORMATION ............................................................3
2.0 GENERAL INFORMATION ...............................................................................4
2.1 Introduction ....................................................................................................4
2.3 Importance of Quality Installation..................................................................4
2.4 System Sizing and Selection.........................................................................4
2.5 Importance of Proper Indoor/Outdoor Match-Ups ........................................5
2.6 Checking Product Received ..........................................................................5
2.7 Compressor Break-In Notice .......................................................................5
3.0 UNIT SPECIFICATIONS ....................................................................................5
3.1 Model Number Nomenclature and Available Models....................................5
3.0 UNIT SPECIFICATIONS ....................................................................................6
3.2 Electrical and Physical Data..........................................................................6
4.0 INSTALLATION..................................................................................................7
4.1.1 Tools Required for Installing and Servicing R-410A Models.................7
4.1.2 Specications of R-410A .......................................................................7
4.1.3 Quick-Reference Guide for R-410A ......................................................7
4.1 Tools and Refrigerant.....................................................................................7
4.2 Choosing a Location ......................................................................................8
4.2.1 Allowable Clearances............................................................................8
4.2.2 Operational Issues Related to Unit Location........................................8
4.2.3 Corrosive Environment..........................................................................8
4.2.4 Customer Satisfaction Issues ...............................................................9
4.3 Unit Mounting.................................................................................................9
4.3.1 Unit Mounting Methods .........................................................................9
4.3.2 High Wind and Seismic Tie-Down Methods.........................................9
4.3.3 Elevating Unit ........................................................................................9
4.4 Refrigerant Line Set Selection.....................................................................10
4.4.1 Replacing Existing Systems................................................................10
4.4.2 Line Set Application Considerations...................................................10
4.4.2.1 Oil Return to Compressor ............................................................. 10
4.4.2.2 Refrigerant Migration During Off Cycle........................................ 10
4.4.2.3 Maximum Liquid Pressure Drop ................................................... 10
4.4.2.4 Liquid Line Refrigerant Flashing................................................... 10
4.4.2.5 Oil Level Adjustment for Long Line Set Applications ................... 10
4.4.2.6 Capacity Losses............................................................................ 10
4.4.4 Liquid Line Selection ........................................................................... 11
4.4.5 Vapor Line Selection ...........................................................................12
4.5 Line Set Installation .....................................................................................14
4.5.1 Important Tubing Installation Practices...............................................14
4.5.2 Relative Location of Indoor and Outdoor Units ..................................15
4.5.2.2 Outdoor Unit Below Indoor Coil (Long Line Set Applications)..... 16
4.5.3 Tubing Connections ............................................................................18
4.6 Initial Leak Testing ......................................................................................19
4.7 Evacuation ...................................................................................................19
4.8 Final Leak Testing........................................................................................20
4.9 Control Wiring ..............................................................................................20
4.9.1 EcoNet™Communications...................................................................20
4.9.2 EcoNet™Control Center Installation ...................................................20
4.9.3 EcoNet™Communication Wiring Connections ...................................20
4.9.4 Conventional 24VAC Thermostat Control Wiring Connections..........21
4.10 Power Wiring ..............................................................................................22
4.11 Grounding ...................................................................................................22
5.0 SYSTEM START-UP & REFRIGERANT CHARGING....................................23
5.1 System Start-Up Overview ..........................................................................23
5.2 Initial Power-Up............................................................................................23
and EcoNet™Communication Verification.........................................................23
5.3 EcoNet™ Control Center Set-Up.................................................................23
5.4 Initial System Start-Up.................................................................................23
5.5 Entering Charge Mode Using EcoNet™Control Center Service Menu.......23
5.6 Entering Charge Mode When Using a Conventional 24VAC Thermostat ..23
5.7 Indoor Air-Flow Verification ........................................................................24
5.8 Refrigerant Charging ...................................................................................24
5.8.1 Measurement Device Set-Up..............................................................25
5.8.2 Preliminary Charging by Weight .........................................................25
5.8.3 Preliminary Charging by Pressures (Optional)...................................25
5.8.5 R-410A Temperature Pressure Chart .................................................26
5.9 Completing Installation ...............................................................................26
5.8.4 Final Charging by Liquid Subcooling ..................................................26
6.0 NORMAL SEQUENCE OF OPERATION........................................................27
6.1 Cooling Mode ...............................................................................................27
6.2 On-Demand Cooling Dehumidification .......................................................27
6.3 Low Ambient Cooling Mode.........................................................................27
6.4 Heating Mode...............................................................................................27
6.5 Supplemental Electric Heat in Heating Mode.................................................28
6.6 Dual Fuel Applications – Heating Mode..........................................................28
6.7 Demand Defrost...........................................................................................28
6.8 Sequence of Operation for Conventional 24VAC Thermostat Controls .....29
7.1.1 Board Features and Connections .......................................................30
7.0 COMPONENTS & CONTROLS .......................................................................30
7.2 Power Inverter Compressor Control............................................................31
8.0 ACTIVE SYSTEM PROTECTION FEATURES ...............................................32
8.1 Minimum Run Timer.....................................................................................32
8.2 Oil Return Cycle...........................................................................................32
8.3 Off-Cycle Refrigerant Migration – Stator Heat............................................32
8.4 High Discharge Temperature.......................................................................32
8.5 High Discharge Pressure........................................................................................ 32
8.6 Low Suction Pressure /Loss of Charge ...................................................................... 32
8.7 Compressor Shut-Down Sequence for High or Low Refrigerant Pressure Fault.. 33
8.8 Overcurrent and Current Imbalance....................................................................... 33
8.9 Compressor Operation Outside Envelope ............................................................. 33
8.10 Over and Under Voltage ....................................................................................... 33
8.11 Inverter Over Temperature.................................................................................... 33
8.12 Controls and Communication Malfunction ........................................................... 33
8.13 Sensor Failure Default Operation ......................................................................... 33
8.14 Exiting Active Protection Lock-Out Mode............................................................. 33
9.0 DIAGNOSTICS & TROUBLESHOOTING............................................................. 34
9.1 Checking Transducers & Temperature Sensors..................................................... 36
9.3 Service Analyzer Charts......................................................................................... 39
9.4 Troubleshooting Tips .............................................................................................. 43
10.0 OUTDOOR UNIT MAINTENANCE...................................................................... 44
10.1 Outdoor Coil Cleaning........................................................................................... 44
10.2 Cabinet Cleaning and Care .................................................................................. 44
10.3 Motor Lubrication.................................................................................................. 44
10.4 Replacement Parts ............................................................................................... 44
11.0 WIRING DIAGRAM .............................................................................................. 45
12.0 APPENDIX............................................................................................................ 47
12.1 Agency Performance Audit Test Instructions ....................................................... 47
List of Tables
Table 1: Available Models............................................................................................5
Table 2: Electrical Data ................................................................................................6
Table 3: Physical Data ..................................................................................................6
Table 4: Dimensions.....................................................................................................6
Table 5: Equivalent Length for Fittings: ft [m] .......................................................11
Table 6A: Refrigerant Line Sizing Chart (English Units).......................................12
Table 6B: Refrigerant Line Sizing Chart (Metric Units) .........................................13
Table 7: Wire Color Code ...........................................................................................21
Table 8: Voltage Ranges (60 Hz) ...............................................................................22
Table 9: Cooling and Heating CFM Ratings.............................................................24
Table 10: R-410A Temperature Pressure Chart.......................................................26
Table 11: Coil Temperature Switch Settings ...........................................................29
Table 12: Features on the UODC and Location of Each ........................................30
Table 13: Features on the Power Inverter Compressor Control...........................31
Table 14: Sensor Failure Identification Chart .........................................................34
Table 15: EcoNetTM Fault Codes & Response Actions ...........................................34
Table 16: Temperature Sensor to Resistance Measurement Chart .....................37
Table 17: Troubleshooting Guide..............................................................................38
Table 18: Service Analyzer Chart .............................................................................39
Table 19: Cooling Mode Trouble Shooting Tips......................................................43
Table 20: Heating Mode Trouble Shooting Tips......................................................44
List of Figures
Figure 1: Unit Dimensions & Clearances................................................................... 6
Figure 2: Required Tools for Unit Installation .......................................................... 7
Figure 3: Required Clearances for Unit Installation ................................................ 8
Figure 4: Elevated Unit Mounting Recommendations............................................. 9
Figure 5: Temporary Hanger and Permanent Hanger............................................ 14
Figure 6: Isolate Vapor Line from Building Structure............................................ 14
Figure 7: Debur Cut Tubing Ends ............................................................................. 14
Figure 8: Slop Vapor Line Toward the Indoor Unit................................................. 15
Figure 9: Long Line Liquid Line Routing................................................................. 16
Figure 10: Liquid Line Routing for Unit Installed Above Indoor Coil .................. 17
Figure 11: "L" Type Refrigeration Tubing Locations.............................................. 18
Figure 12: Remove Caps and Schrader Cores........................................................ 18
Figure 13: Clean Inside Fittings and Outside Tubing ............................................ 18
Figure 14: Wrap Valves Before Applying Heat........................................................ 18
Figure 15: Braze the Tubing ...................................................................................... 18
Figure 16: Cool the Joint After Brazing ................................................................... 18
Figure 17: Do Allow the Vapor and Liquid Lines to Cross..................................... 18
Figure 18: Pressurize Line Set.................................................................................. 19
Figure 19: Insulate Vapor Line .................................................................................. 19
Figure 20: Evacuate Air and Moisture from System .............................................. 19
Figure 21: Open Both Service Valves ...................................................................... 20
Figure 22: Connect Gauges....................................................................................... 20
Figure 23: Low Voltage EcoNetTM Wiring................................................................ 21
Figure 24: Typical Single-Stage Thermostat: (-)P18AZ Heat Pump With Air Hand-
ler Using A Thermostat With Dehumidification............................................ 21
Figure 25: Typical Single-Stage Thermostat: Heat Pump With Air-Handler ...... 21
Figure 26: Typical Single-Stage Thermostat And Dual-Fuel Application ........ 22
Figure 27: Ground Lug Locations............................................................................. 22
Figure 28: Apply Power with EcoNetTM Switched Off............................................. 23
Figure 29: Run the Unit for 15 Minutes .................................................................... 25
Figure 30: EcoNet™ Universal Outdoor Control (UODC) Connection Diagram 30
Figure 31: Power Inverter Compressor Control Diagram...................................... 31
Figure 32: (-)A18AZ Wiring Diagram & Schematic Diagram.................................. 45
Figure 33: (-)P18AZ Wiring Diagram & Schematic Diagram.................................. 46
Figure 34: Thermostat Wiring for Heat Pump with Air Handler............................ 47
Figure 35: Thermostat Wiring for Heat Pump with Coil and Furnace.................. 47

Safety
3
1.0 IMPORTANT SAFETY INFORMATION
WARNINGS:
• These instructions are intended as an aid to
qualified, licensed service personnel for proper
installation, adjustment, and operation of this unit.
Read these instructions thoroughly before attempting
installation or operation. Failure to follow these
instructions may result in improper installation,
adjustment, service, or maintenance possibly
resulting in fire, electrical shock, property
damage, personal injury, or death.
• The unit must be permanently grounded. Failure
to do so can cause electrical shock resulting in
severe personal injury or death.
• Turn off electric power at the fuse box or service
panel before making any electrical connections.
• Complete the ground connection before making
line voltage connections. Failure to do so can
result in electrical shock, severe personal injury,
or death.
• Disconnect all power to unit before starting
maintenance. Failure to do so can cause
electrical shock resulting in severe personal
injury or death.
• Never assume the unit is properly wired and/or
grounded. Always test the unit cabinet with a
noncontact voltage detector available at most
electrical supply houses or home centers before
removing access panels or coming into contact
with the unit cabinet.
• DO NOT use oxygen to purge lines or pressurize
system for leak test. Oxygen reacts violently with
oil, which can cause an explosion resulting in
severe personal injury or death.
• The top of the scroll compressor shell is hot.
Touching the compressor top may result in serious
personal injury.
• The manufacturer’s warranty does not cover
any damage or defect to the unit caused by the
attachment or use of any components, accessories,
or devices (other than those authorized by the
manufacturer) into, onto, or in conjunction with the
heat pump. You should be aware that the use
of unauthorized components, accessories, or
devices may adversely affect the operation
of the heat pump and may also endanger life
and property. The manufacturer disclaims any
responsibility for such loss or injury resulting
from the use of such unauthorized components,
accessories, or devices.
• This product is not approved for installation at
6561 feet [2000 meters] above sea level or higher.
Installation at higher altitudes may result in control
and unit failures due to electrical arc tracking
between electrical components on the invertor drive
control board. Possibly resulting in fire, electrical
shock, property damage, personal injury, or death.
CAUTIONS:
• R-410A systems operate at approximately 60% higher
pressures (1.6 times) than R-22 systems. Do not use
R-22 service equipment or components on R-410A
equipment. Use appropriate care when using this
refrigerant. Failure to exercise care may result in
equipment damage or personal injury.
• Only match this outdoor unit with a matched indoor
coil or air handler approved for use with this outdoor
unit per the unit manufacturer’s specification sheet.
The use of unmatched coils or air handler will likely
result in a charge imbalance between the cooling
and heating modes which can cause unsatisfactory
operation including a high-pressure switch lockout
condition.
• Only use indoor coils approved for use on R-410A
systems. An R-22 coil will have a TXV or fixed
expansion device that is not designed to operate
properly in an R-410A system and will result in
serious operational issues. The R-22 coil could also
contain a significant amount of mineral oil which
is incompatible with the POE oil used in R-410A
systems and could result in reliability issues with the
compressor and expansion devices.
• When the indoor coil or air handler is installed over
a finished ceiling and/or living area, it is required that
an auxiliary overflow pan be constructed and installed
under the entire indoor unit. Failure to do so can
result in property damage.
• The blue cooling status LED shall blink (1 second
ON, 1 second OFF) if waiting for the short cycle
timer (LOCKTIMR) to expire, otherwise it shall blink
the first digit of the capacity percentage requested
(for example, blink 7 times for 70% capacity). At
100% capacity the LED shall be solid on. The
orange heating status LED shall blink (1 second ON,
1 second OFF) if waiting for the short cycle timer
(LOCKTIMR) to expire, otherwise it shall blink the
first digit of the capacity percentage requested (for
example, blink 7 times for 70% capacity). At 100%
capacity the LED shall be solid on.

4
2.0 GENERAL INFORMATION
2.1 Introduction
The (-)A18AZ/(-)P18AZ series heat pumps are
specifically designed to operate with matching
communicating EcoNet™ enabled air-handlers, gas
furnaces, and Control Center. A conventional 24VAC
2-stage thermostat can be used, but many features
and benefits are lost, so this is only recommended for
emergency situations when there are issues with the
EcoNet™ communications and the system must be
made operational until the communication issues are
resolved.
This installation instruction manual contains complete
instructions for installation and setup using the
EcoNet™ or conventional 24VAC controls. Please refer
to the manufacturer's specification sheets for complete
performance data, thermostat, and accessory listings.
The information contained in this manual has been
prepared to assist in the proper installation, operation,
and maintenance of the air conditioning system.
Read this manual and any instructions packaged with
separate equipment required to make up the system
prior to installation. Homeowner should retain this
manual for future reference.
2.2 Agency Performance Audit
Testing Notice
For purposes of verifying or testing efficiency
ratings, the test procedure in Title 10 APPENDIX M
to Subpart B of Part 430 (Uniform Test Method for
Measuring the Energy Consumption of Central Air
Conditioners and Heat Pumps) and the clarifying
provisions provided in the AHRI Operations
Manual 210/240 that were applicable at the date of
manufacture should be used for test set up and
performance.
Should this unit be selected for performance audit
testing, follow the instructions included in the Appendix
(Section 12.1) of this manual.
2.3 Importance of Quality
Installation
A quality installation is critical to assure safety, reliability, comfort,
and customer satisfaction. Strict adherence to applicable codes,
the information in this installation manual, the outdoor unit
installation manual, and the thermostat installation manual are
key to a quality installation. Read the entire instruction manuals
before starting the installation.
IMPORTANT: This product has been designed and manufactured
to meet certified AHRI capacity and efficiency ratings with the
appropriate outdoor units. However, proper refrigerant charge,
proper airflow, and refrigerant line sizing are critical to achieve
optimum capacity and efficiency and to assure reliable operation.
Installation of this product should follow the manufacturer’s
refrigerant charging and airflow instructions located in this
installation manual and the charging chart label affixed to the
outdoor unit. Failure to confirm proper charge and airflow may
reduce energy efficiency and shorten equipment life.
The equipment has been evaluated in accordance with the Code
of Federal Regulations, Chapter XX, Part 3280.
Install the unit in accordance with applicable national, state, and
local codes. Latest editions are available from: “National Fire
Protection Association, Inc., Batterymarch Park, Quincy, MA
02269.” These publications are:
• ANSI/NFPA No. 70-(Latest Edition) National
Electrical Code.
• NFPA90A Installation of Air Conditioning and
Ventilating Systems.
• NFPA90B Installation of warm air heating and air
conditioning systems.
• Install the unit in such a way as to allow necessary
access to the coil/filter rack and blower/control
compartment.
2.4 System Sizing and Selection
Before specifying any heat pump equipment, a
survey of the structure and heat loss and heat gain
calculations must be made. A heat loss calculation
involves identifying all surfaces and openings that
lose heat to the surrounding air in the heating mode
and quantifying that heat loss. A heat gain calculation
makes similar measurements and determines the
amount of heat required to be removed in the cooling
mode. A heat gain calculation also calculates the extra
heat load caused by sunlight and by humidity removal.
These factors must be considered before selecting
a heat pump system to provide year-round comfort.
The Air Conditioning Contractors of America (ACCA)
Manual J method of load calculation is one recognized
procedure for determining the heating and cooling
load.
After the proper equipment combination has
been selected, satisfying both sensible and latent
requirements, the system must be properly installed.
Only then can the system provide the comfort it was
designed to provide.
There are several factors that installers must consider.
• Outdoor unit location
• Indoor unit blower speed and airflow
• Proper equipment evacuation
• Supply and return air duct design and sizing
• Refrigerant charge
• System air balancing
• Diffuser and return air grille location and sizing
IMPORTANT: Excessive use of elbows in the
refrigerant line set can produce excessive pressure
General Information
WARNING:
Improper installation, or installation not made in
accordance with these instructions, can result in
unsatisfactory operation and/or dangerous conditions and
can cause the related warranty not to apply.

5
3.0 UNIT SPECIFICATIONS
General Information Unit Specications
drop. Follow industry best practices for installation.
Installation and commissioning of this equipment
is to be performed by trained and qualified HVAC
professionals. For technical assistance, contact your
Distributor Service Coordinator.
2.5 Importance of Proper Indoor/
Outdoor Match-Ups
To assure many years of reliable operation and
optimum customer comfort and to assure the outdoor
unit warranty remains valid, an air-handler model or
indoor coil/furnace combination should be selected
that is properly matched to the outdoor unit. This is
especially critical for heat pump systems to assure
proper refrigerant charge balance between the cooling
and heating modes. The recommended approach is to
select an air-handler or indoor coil and gas furnace that
has an AHRI match with the outdoor unit. Refer to the
AHRI directory at www.ahridirectory.org to confirm the
air-handler and outdoor unit are a certified combination
in the AHRI Directory.
2.6 Checking Product Received
Upon receiving unit, inspect it for any shipping damage.
Claims for damage, either apparent or concealed,
should be filed immediately with the shipping company.
Check model number, electrical characteristics, and
accessories to determine if they are correct. Check
system components (indoor coil, outdoor unit, air
handler/furnace, etc.) to make sure they are properly
matched.
2.7 Compressor Break-In Notice
Prior to agency testing, system must be operated for 20
hours at 115ºF [46.1ºC] outdoor ambient temperature
with 80ºF [26.7ºC] dry bulb 75ºF
[23.9ºC] wet bulb indoor ambient temperature to break
the compressor in.
3.1 Model Number Nomenclature and Available Models
R P 18
C
Y
24 A J V C A
MINOR SERIES
CONTROLS
TYPE
1 =-1 STAGE
2 =2 STAGE
3 =-3 STAGE
V =FULLY VARIABLE
VOLTAGE
J=1PH 208-230 VAC 60 Hz
MAJOR
SERIES
CAPACITY
24 = 24000BTU/HR
36 = 36000BTU/HR
48 = 48000BTU/HR
60 =60000BTU/HR
REFRIGERANT
Z=R-410A
Y=R-454B
W = FUTURE REFRIGERANT
REGION
C =COLD CLIMATE
SEER2
PRODUCT CATEGORY
P =HEAT PUMP
D =SIDE DISCHARGE HEAT PUMP
A =AIR CONDITIONER
BRAND
R = RHEEM
U = RUUD
S = SURE COMFO
ML = MAINLINE
RT
Table 1: Available Models
Heat Pumps Air Conditioners
(-)P18AZ24AJVCA (-)A18AZ24AJVCA
(-)P18AZ36AJVCA (-)A18AZ36AJVCA
(-)P18AZ48AJVCA (-)A18AZ48AJVCA
(-)P18AZ60AJVCA (-)A18AZ60AJVCA

6
“L”
“W”
“H”
ST-A1226-02-00
1
2
3
3.0 UNIT SPECIFICATIONS
Unit Specications
3.2 Electrical and Physical Data
Table 2: Electrical Data
Model
Number
(-)P18AZ
Phase
Frequency (Hz)
Voltage (Volts)
Compressor Fan Motor
Full Load
Amperes (FLA)
Minimum Circuit
Ampacity Amperes
Fuse or HACR Circuit Breaker
Rated Load
Amperes (RLA)
Locked Rotor
Amperes (LRA)
Minimum
Amperes
Maximum
Amperes
24 1-60-208/230 15.4 35 1.9 21 25 30
36 1-60-208/230 24.0 50 1.8 32 40 50
48 1-60-208/230 28.1 50 1.2 34 50 60
60 1-60-208/230 31.7 50 2.0 42 50 60
Table 3: Physical Data
Model Number
(-)P18AZ
Outdoor Coil Refrig. Per
Circuit Oz. [g]
Weight
Face Area
Sq. Ft. [m2]No. Rows Net. Lbs. [kg] Shipping Lbs. [kg]
24 28.40 [2.6] 1210 [5953] 278 [126] 282 [128]
36 32.44 [3.0] 1212 [6010] 298 [135] 306 [139]
48 32.44 [3.0] 1222 [6282] 298 [135] 306 [139]
60 32.44 [3.0] 1252 [7144] 301 [137] 309 [140]
Model Number
(-A20
Outdoor Coil Refrig. Per
Circuit Oz. [g]
Weight
Face Area
Sq. Ft. [m2]No. Rows CFM [L/s] Net. Lbs. [kg] Shipping Lbs. [kg]
24 22.23 13328/1796/1264 148 (4195) 198 206
36 22.34 14313/2065/1050 1936 (5488) 236 244
48 32.45 16242/3212/1853 196 (5556) 255 263
60 32.45 26173/2932/1466 376 (10659) 300 307
Table 4: Dimensions
(-)P18AZ 24A 36A 48A 60A
Height "H" inches [cm] 45 [114.3] 51 [129.5] 51 [129.5] 51 [129.5]
Length "L' inches [cm] 35.75 [90.8] 35.75 [90.8] 35.75 [90.8] 35.75 [90.8]
Width "W" inches [cm] 35.75 [90.8] 35.75 [90.8] 35.75 [90.8] 35.75 [90.8]
(-)A18AZ 24A 36A 48A 60A
Height "H" inches [cm] 39 [91.1] 39 [91.1] 51 [129.5] 51 [129.5]
Length "L' inches [cm] 33.75 [85.7] 33.75 [85.7] 35.75 [90.8] 35.75 [90.8]
Width "W" inches [cm] 33.75 [85.7] 33.75 [85.7] 35.75 [90.8] 35.75 [90.8]
Figure 1: Unit Dimensions & Clearances
Item Number Item Description Clearance Needed
1 Air Inlet Louvers 6" [15.2 cm] All Sides
12" [30.5 cm] Recommended
2Service Panels/ Inlet Connections /
High & Low Voltage Access 24" [61.0 cm]
3Air Discharge 60" [152.4 cm]
Fuse or HACR Circuit Breaker
Compressor
Rated Load
Amperes
(RLA)
Locked Rotor
Amperes
(LRA)
Model
Number
(-)A18AZ
Phase
Frequency (Hz)
Voltage (Volts)
Fan Motor
Full Load
Amperes
(FLA)
Minimum
Amperes
Maximum
Amperes
24
36
48
60
1-60-208/230
1-60-208/230
1-60-208/230
1-60-208/230
15.0/15.0
20.1/20.1
32.0/32.0
34.1/34.1
35
35
50
50
1.4
3.5
5.3
5.3
25
35
60
60
35
45
70
80

7
4.0 INSTALLATION
Tools
4.1 Tools and Refrigerant
4.1.1 Tools Required for Installing
and Servicing R-410A Models
Manifold Sets:
– Up to 800 PSIG [5,516 kPa] High-Side
– Up to 250 PSIG [1,724 kPa] Low-Side
– 550 PSIG [3,792 kPa] Low-Side Retard
Manifold Hoses:
– Service Pressure Rating of 800 PSIG [5,516 kPa]
Recovery Cylinders:
– 400 PSIG [2,758 kPa] Pressure Rating
– Dept. of Transportation 4BA400 or BW400
Item Number Descripton
1Ambient and Tube Thermometers
2Crescent Wrench
3Allen Wrench
4 Manifold Gauge Set
5Brazing Rods
6Recovery Cylinders
7Nitrogen
8Torch
9Reclaimer
Figure 2: Required Tools for Unit Installation
CAUTION:
R-410A systems operate at higher pressures than
R-22 systems. Do not use R-22 service equipment or
components on R-410A equipment.
4.1.2 Specications of R-410A
Application: R-410A is not a drop-in replacement
for R-22.Equipment designs must accommodate its
higher pressures. It cannot be retrofitted into R-22 heat
pumps.
Physical Properties: R-410A has an atmospheric
boiling point of -62.9°F [-52.7°C] and its saturation
pressure at 77°F [25°C] is 224.5 psig [1,548 kPa].
Composition: R-410A is a near-azeotropic mixture of
50% by weight difluoromethane (HFC-32) and 50% by
weight pentafluoroethane (HFC-125).
Pressure: The pressure of R-410A is approximately
60% (1.6 times) greater than R-22. Recovery and
recycle equipment, pumps, hoses, and the like must
have design pressure ratings appropriate for R-410A.
Manifold sets need to range up to 800 psig [5,516
kPa] high-side and 250 psig [1,724 kPa] low-side with
a 550 psig [3,792 kPa] low-side retard. Hoses need to
have a service pressure rating of 800 psig [5,516 kPa].
Recovery cylinders need to have a 400 psig [2,758
kPa] service pressure rating, DOT 4BA400 or DOT
BW400.
Combustibility: At pressures above 1 atmosphere, a
mixture of R-410A and air can become combustible.
R-410A and air should never be mixed in tanks
or supply lines or be allowed to accumulate in
storage tanks. Leak checking should never be
done with a mixture of R-410A and air. Leak-
checking can be performed safely with nitrogen or a
mixture of R-410A and nitrogen.
4.1.3 Quick-Reference Guide for
R-410A
• R-410A refrigerant operates at approximately 60%
higher pressure (1.6 times) than R-22. Ensure that
servicing equipment is designed to operate with
R- 410A .
• R-410A refrigerant cylinders are light rose in color.
• R-410A, as with other HFCs, is only compatible
with POE oils.
• Vacuum pumps will not remove moisture from POE
oil used in R-410A systems.
• R-410A systems are to be charged with liquid
refrigerants. Prior to March 1999, R-410A
refrigerant cylinders had a dip tube. These
cylinders should be kept upright for equipment
charging. Post-March 1999 cylinders do not have
a dip tube and should be inverted to ensure liquid
charging of the equipment.
• Do not install a suction line filter drier in the liquid
line.
• A factory-approved bi-flow liquid line filter drier
is shipped with every unit and must be installed
in the liquid line at the time of installation. Only
manufacturer-approved liquid line filter driers
should be used. Filter driers must have a working
pressure rating of at least 600 psig [4,137 kPa].
The filter drier will only have adequate moisture-
holding capacity if the system is properly
evacuated.
• Desiccant (drying agent) must be compatible for
POE oils and R-410A refrigerant.
12
3
4
5
6
7
89

8
4.2 Choosing a Location
4.2.1 Allowable Clearances
12" [30.5 cm] to side intake louvers
24" [61.0 cm] to service access panels
60" [152.4 cm] vertical for fan discharge
If space limitations exist, the following clearances will
have minimal impact to capacity and efficiency and
are permitted:
Single-Unit Applications: Minimum of 6" [15.2 cm]
to side intake louvers. DO NOT reduce the 60" [152.4
cm] for fan discharge or the 24" [61.0 cm] service
clearances.
Multiple-Unit Applications: For units positioned next
to each other, a minimum of 6" [15.2 cm] clearance
between units is recommended for 2 ton models and
9" [22.9 cm] for 3 ton to 5 ton models. Do not reduce
the 60" [152.4 cm] for fan discharge or the 24" [61.0
cm] service clearances.
IMPORTANT: Consult local and national building
codes and ordinances for special installation
requirements. Following location information will
provide longer life and simplified servicing of the
outdoor heat pump.
NOTICE: These units must be installed outdoors.
No ductwork can be attached, or other modifications
made, to the discharge grille. Modifications will affect
performance or operation.
Item Number Item Description Clearance Needed
1 Air Inlet Louvers 6" [15.2 cm] All Sides
12" [30.5 cm] Recommended
2
Service Panels
Inlet Connections
High & Low Voltage Access
24" [61.0 cm]
3Air Discharge 60" [152.4 cm]
4 Space Between Units 12” Min. (30.5 cm)
24” [61.0 CM] Recommended
Figure 3: Required Clearances for Unit Installation
4.2.2 Operational Issues Related to
Unit Location
IMPORTANT: Locate the unit in a manner that will
not prevent, impair, or compromise the performance
of other equipment installed in proximity to the
unit. Maintain all required minimum distances to
gas and electric meters, dryer vents, and exhaust
and inlet openings. In the absence of national
codes or manufacturers’ recommendations, local
code recommendations and requirements will take
precedence.
• Refrigerant piping and wiring should be properly
sized and kept as short as possible to avoid capacity
losses and increased operating costs.
• Locate the unit where water runoff will not create a
problem with the equipment. Position the unit away
from the drip edge of the roof whenever possible.
Units are weatherized, but can be affected by the
following:
• Water pouring into the unit from the junction
of rooflines, without protective guttering. Large
volumes of water entering the heat pump while in
operation can impact fan blade or motor life, and
coil damage may occur to a heat pump if moisture
cannot drain from the unit under freezing conditions.
• Freezing moisture or sleeting conditions can cause
the cabinet to ice-over prematurely and prevent
heat pump operation, requiring backup heat, which
generally results in less economical operation It is
highly recommended to switch the EcoNet™ Control
Center or thermostat to the "Emergency Heat" mode
during freezing rain or sleeting conditions to prevent
damage to the outdoor coil from ice accumulating on
the fan blade.
• Closely follow the clearance recommendations in
section 4.2.1.
• 24" [61.0 cm] to the service panel access.
• 60" [152.4 cm] above the fan discharge (unit
top) to prevent recirculation.
• 6" [15.2 cm] to the coil grille air inlets
with 12" [30.5 cm] minimum recommended.
4.2.3 Corrosive Environment
The metal parts of this unit may be subject to rust or
deterioration if exposed to a corrosive environment.
This oxidation could shorten the equipment’s useful
life.
Corrosive elements include, but are not limited to,
salt spray, fog or mist in seacoast areas, sulphur or
chlorine from lawn watering systems, and various
chemical contaminants from industries such as paper
mills and petroleum refineries.
If the unit is to be installed in an area where
contaminants are likely to be a problem, special
attention should be given to the equipment location
and exposure.
• Avoid having lawn sprinkler heads spray directly on
the unit cabinet.
• In coastal areas, locate the unit on the side of the
building away from the waterfront.
• Shielding provided by a fence or shrubs may give
some protection, but cannot violate minimum airflow
and service access clearances.
Location
ST-A1226-04-00
1
2
3
4

9
Location
WARNING:
Disconnect all power to unit before starting
maintenance. Failure to do so can cause electrical
shock resulting in severe personal injury or death.
Regular maintenance will reduce the buildup of
contaminants and help to protect the unit’s finish.
• Frequent washing of the cabinet, fan blade,
and coil with fresh water will remove most of
the salt or other contaminants that build up on
the unit.
• Regular cleaning and waxing of the cabinet
with a good automobile polish will provide
some protection.
• A good liquid cleaner may be used several
times a year to remove matter that will not wash
off with water.
4.2.4 Customer Satisfaction Issues
• The heat pump should be located away from the
living, sleeping, and recreational spaces of the
owner and those spaces on adjoining property.
• To prevent noise transmission, the mounting pad
for the outdoor unit should not be connected to
the structure and should be located a sufficient
distance above grade to prevent ground water
from entering the unit.
4.3 Unit Mounting
4.3.1 Unit Mounting Methods
The outdoor heat pump unit may be mounted in a
number of ways. The most common method is on the
ground mounted on a concrete or pre-fabricated pad.
It can also be mounted on a ground or roof mounted
metal frame, wooden frame, or 4” x 4” [10.2 cm x 10.2
cm] wooden stringers. It is extremely important to
properly secure the unit to the pad or frame so it does
not shift during high winds, seismic events, or other
outside forces to eliminate the possibility of a safety
hazard or physical damage to the unit. Local codes
in regions subject to frequent hurricanes and seismic
events will dictate specific mounting requirements and
must be followed. It is also important to elevate the
heat pump in areas that receive a significant amount
of snowfall so accumulated snow does not block
the outdoor coil and interfere with drainage of water
during the defrost cycle. Refer to Section 4.3.4 for
typical ground snow levels for different regions of the
USA.
4.3.2 High Wind and Seismic Tie-
Down Methods
The manufacturer-approved/recommended method
is a guide to securing equipment for wind and
seismic loads. Other methods might provide the
same result, but the manufacturer method is the
only one endorsed by the manufacturer for securing
equipment where wind or earthquake damage
can occur. Additional information is available on
the manufacturer's website or from the wholesale
distributor.
4.3.3 Elevating Unit
WARNING:
Secure an elevated unit and its elevating stand in
order to prevent tipping. Failure to do so may result in
severe personal injury or death.
If elevating the heat pump, either on a flat roof or on a
ST-A1226-03-00
1
2
3
Figure 4: Elevated Unit Mounting Recommendations
Item Number Descripton
1 Elevate Above Anticipated High Snow Fallt
2 Do Not Block Openings In Base Pan
3 Base Pad (Concrete Or Other Suitable Material)

10
Location
slab, observe the following guidelines.
• If elevating a unit on a flat roof, use 4" x 4"
[10.2 cm x 10.2 cm] or equivalent stringers
positioned to distribute unit weight evenly and
prevent noise and vibration.
• Heat pump products will need to be elevated per
local climate and code requirements to provide
clearance above the estimated snowfall level to
ensure the unit will be protected from damage.
Failure to follow these instructions may result in
equipment damage and improper operation.
NOTICE: Do not block drain openings on bottom of unit.
• If unit must be elevated because of anticipated
snowfall, secure unit and elevating stand such that
unit and/or stand will not tip over or fall off. Keep in
mind that someone may try to climb on unit.
4.4 Refrigerant Line Set Selection
4.4.1 Replacing Existing Systems
To prevent failure of a new unit, the existing line set must
be correctly sized for the new unit and must be cleaned
or replaced. Care must be taken so the expansion device
is not plugged. For new and replacement units, a liquid
line filter drier must be installed and the line set must be
properly sized. Test the oil for acid. If it tests positive for
acid, a suction line filter drier is mandatory.
IMPORTANT: When replacing an R-22 unit with an
R-410A unit, either replace the line set or ensure
that residual mineral oil is drained from existing lines
including oil trapped in low spots.
4.4.2 Line Set Application
Considerations
The following are special considerations that need to be
addressed when selecting and installing a line set.
• Additional refrigerant charge
• Fitting losses and maximum equivalent length
considerations
• Refrigerant migration during the off cycle
• Oil return to the compressor
• Capacity losses
• System oil level adjustment
4.4.2.1 Oil Return to Compressor
Small amounts of compressor crankcase oil is picked
up and carried out of the compressor by the moving
refrigerant and is circulated through the system along
with the refrigerant before it returns to the compressor
crankcase. It is critical to the life of the compressor for
the oil to be able to return to the compressor to maintain
an adequate level of oil in the compressor crankcase.
Oversized vapor lines result in inadequate refrigerant
velocities to carry the oil along with the refrigerant and
will cause the oil to accumulate in the low spots in the
vapor line instead of being returned to the compressor
crankcase. This is especially true for long line lengths.
Variable speed systems present an additional challenge
due to the fact that the system operates at a significantly
reduced refrigerant flow rate for a significant percentage
of operating time. Only use the vapor line sizes
listed in Table 2 to assure proper oil return. DO NOT
oversize vapor line!
4.4.2.2 Refrigerant Migration During O󰀨
Cycle
Long line set applications can require a considerable
amount of additional refrigerant. This additional
refrigerant needs to be managed throughout the
entire ambient operating envelope that the system will
go through during its life cycle. Off-Cycle migration
is where excess refrigerant condenses and migrates
to the coldest and/or lowest part of the system.
Excessive build-up of refrigerant at the compressor
will result in poor reliability and noisy operation during
startup. Section 4.5.2 demonstrates the required unit
configuration for different applications.
The outdoor unit controls can energize a portion of
the compressor motor stator as needed during the off
cycle to prevent liquid refrigerant from accumulating
inside the compressor, similar to how a crankcase
heater functions on conventional systems.
4.4.2.3 Maximum Liquid Pressure Drop
The total liquid line pressure drop must not exceed
50 psig [345 kPa] to assure a solid column of liquid at
the metering device and stable control of superheat.
Be sure to account for vertical separation, elbows,
filter driers, solenoid valves, sight glasses, and check
valves when calculating liquid line pressure drop.
4.4.2.4 Liquid Line Refrigerant Flashing
Excessive pressure drop and heat gain in long liquid
lines can result in the refrigerant flashing into a vapor
before it reaches the expansion device which will
dramatically reduce the capacity and efficiency of
the system. For this reason, the liquid line must be
sized properly using Table 2 and must be insulated in
unconditioned spaces.
4.4.2.5 Oil Level Adjustment for Long Line
Set Applications
Additional oil may need to be added if refrigerant is
added during installation. If the system contains more
than 20 lbs [9 kg] of refrigerant charge, add 1 fluid
oz of POE oil for every 5 lbs [13 ml/kg] of refrigerant
charge over 20 lbs [9 kg].
4.4.2.6 Capacity Losses
Long line lengths can result in a reduction in capacity
due to vapor line pressure drop and heat gain or
loss. Refer to Table 2 for capacity loss multipliers
for various vapor line diameters and equipment line
lengths. This table does not account for any capacity
loss due to heat gain or loss from the environment.
It is extremely important not to oversize the vapor line
to minimize capacity loss at the expense of proper
oil return. If the table shows an “NR” for a particular
vapor line diameter and length, or, if a vapor line
diameter is not listed, oil return will not be adequate.
Tubing

11
Tubing
4.4.3 Line Set Length and Fitting Losses
Refrigerant tubing is measured in terms of actual length and equivalent length. Actual length is used for
refrigerant charge applications. Equivalent length takes into account pressure losses from tubing length,
fittings, vertical separation, accessories, and filter driers. The table below references different commonly
used equivalent lengths.
Table 5: Equivalent Length for Fittings: ft [m]
Line Size
in [mm]
90° Short
Radius
Elbow
90° Long
Radius
Elbow
45°
Elbow
Solenoid
Valve
Check
Valve
Sight
Glass
Filter
Drier
3/8 [9.53] 1.3 [0.40] 0.8 [0.24] 0.3 [0.09] 6 [1.83] 4 [1.22] 0.4 [0.12] 6 [1.83]
1/2 [12.71] 1.4 [0.43] 0.9 [0.27] 0.4 [0.12] 9 [2.74] 5 [1.52] 0.6 [0.18] 6 [1.83]
5/8 [15.88] 1.5 [0.46] 1 [0.30] 0.5 [0.15] 12 [3.66] 6 [1.83] 0.8 [0.24] 6 [1.83]
3/4 [19.05] 1.9 [0.58] 1.3 [0.40] 0.6 [0.18] 14 [4.27] 7 [2.13] 0.9 [0.27] 6 [1.83]
7/8 [22.23] 2.3 [0.70] 1.5 [0.46] 0.7 [0.21] 15 [4.57] 8 [2.44] 1 [0.30] 6 [1.83]
1-1/8 [28.58] 2.7 [0.82] 1.8 [0.55] 0.9 [0.27] 22 [6.71] 12 [3.66] 1.5 [0.46] 6 [1.83]
4.4.4 Liquid Line Selection
The purpose of the liquid line is to transport warm sub-cooled liquid refrigerant between the outdoor unit to the
indoor unit in the cooling mode. In the heating mode, the liquid line returns sub-cooled liquid from the indoor unit
to the outdoor unit. It is important not to allow the refrigerant to flash into superheated vapor prior to entering the
expansion device of the indoor coil or outdoor unit. Flashing of refrigerant can occur for the following reasons:
• Low refrigerant charge
• Improperly selected liquid line size
• Absorption of heat prior to expansion device
• Excessive vertical separation between the outdoor unit and indoor coil
• Restricted liquid linear filter drier
• Kinked liquid line
The total pressure drop allowed for the liquid line is 50 PSI [345 kPa]. The procedure for selecting the proper liquid
line is as follows:
• Measure the total amount of vertical separation between the outdoor unit and indoor coil.
• Measure the total indoor length of liquid line required.
• Add all of the equivalent lengths associated with any fittings or accessories using Table 5.
• Add the linear length to the total fitting equivalent length. This will equal your total equivalent line length.
• Reference Table 6 to verify the calculated equivalent length is acceptable with the required vertical separation
and diameter of liquid line.
Example: A 3-ton heat pump unit is installed 25’ below the indoor unit, requires a 75’ of 1/2” diameter liquid line,
3/4" vapor line, 4 90° LR elbows and a filter drier.
• Fitting Equivalent Length (ft.) = 4 × .9' + 6' = 9.6’
• Total Equivalent Length (ft.) = 75’ + 9.6' = 84.6’
This application is acceptable because the 25’ vertical rise is less than the maximum rise of 50’ for this application.
Example Table (Excerpt from Table 6A)
Unit Size
Allowable
Liquid Line
Size
Allowable
Vapor Line
Size
Outdoor Unit ABOVE or BELOW Indoor Unit
Equivalent Length (Feet)
< 25 26-50 51-75 76-100 101-125 126-150
Maximum Vertical Separation / Capacity Multiplier
3 Ton
5/16" 5/8" 25 / 0.99 50 / 0.97 50 / 0.95 50 / 0.93 36 / 0.91 NR
3/8" 5/8" 25 / 0.99 50 / 0.97 50 / 0.95 50 / 0.93 50 / 0.91 NR
5/16" 3/4" 25 / 1.00 50 / 0.99 50 / 0.99 50 / 0.98 36 / 0.97 20 / 0.96
3/8" 3/4" 25 / 1.00 50 / 0.99 50 / 0.99 50 / 0.98 50 / 0.97 50 / 0.96
1/2" 3/4" 25 / 1.00 50 / 0.99 50 / 0.99 50 / 0.98 50 / 0.97 50 / 0.96

12
Tubing
4.4.5 Vapor Line Selection
The purpose of the vapor line is to return superheated vapor to the condensing unit from the indoor coil in the
cooling mode. While in the heating mode, the vapor line transports discharge vapor to the indoor coil from
the outdoor unit. Proper vapor line sizing is important because it plays an important role in returning oil to the
compressor to prevent potential damage to the bearings, valves, and scroll sets. Also, an improperly sized vapor
line can dramatically reduce capacity and performance of the system. The procedure for selecting the proper
vapor line is as follows:
1. Determine the total linear length of vapor line required.
2. Add all of the equivalent lengths associated with any fittings or accessories using Table 5.
3. Add the linear length and total fitting equivalent length. This will equal your total equivalent line length.
4. Reference Table 6 to verify that the calculated equivalent length falls within the compatibility region of
the chart.
5. Verify capacity loss is acceptable for the application.
Table 6A: Refrigerant Line Sizing Chart (English Units)
18 SEER2 Variable Speed Heat Pumps
Unit Size
Allowable
Liquid Line
Size
Allowable
Vapor Line
Size
Outdoor Unit ABOVE or BELOW Indoor Unit
Equivalent Length (Feet)
< 25 26-50 51-75 76-100 101-125 126-150
Maximum Vertical Separation / Capacity Multiplier
2.0 Ton
*SEE
NOTE 3
1/4" 5/8" 25 /1.00 50 / 0.99 33 / 0.98 6 / 0.97 NR NR
5/16" 5/8" 25 /1.00 50 / 0.99 33 / 0.98 50 / 0.97 50 / 0.96 50 / 0.95
3/8" 5/8" 25 /1.00 50 / 0.99 33 / 0.98 50 / 0.97 50 / 0.96 50 / 0.95
1/4" 3/4" * 25 /1.00 50 / 1.00 33 / 0.99 6 / 0.99 NR NR
5/16" 3/4" * 25 /1.00 50 / 1.00 50 / 0.99 50 / 0.99 50 / 0.99 50 / 0.98
3/8" 3/4" * 25 /1.00 50 / 1.00 50 / 0.99 50 / 0.99 50 / 0.99 50 / 0.98
3 Ton
5/16" 5/8" 25 / 0.99 50 / 0.97 50 / 0.95 50 / 0.93 36 / 0.91 NR
3/8" 5/8" 25 / 0.99 50 / 0.97 50 / 0.95 50 / 0.93 50 / 0.91 NR
5/16" 3/4" 25 / 1.00 50 / 0.99 50 / 0.99 50 / 0.98 36 / 0.97 20 / 0.96
3/8" 3/4" 25 / 1.00 50 / 0.99 50 / 0.99 50 / 0.98 50 / 0.97 50 / 0.96
1/2" 3/4" 25 / 1.00 50 / 0.99 50 / 0.99 50 / 0.98 50 / 0.97 50 / 0.96
4 Ton
3/8" 3/4" 25 / 0.99 50 / 0.98 50 / 0.96 50 / 0.95 50 / 0.93 50 / 0.92
1/2" 3/4" 25 / 0.99 50 / 0.98 50 / 0.96 50 / 0.95 50 / 0.93 50 / 0.92
3/8" 7/8" 25 / 1.00 50 / 0.99 50 / 0.99 50 / 0.98 50 / 0.98 50 / 0.97
1/2" 7/8" 25 / 1.00 50 / 0.99 50 / 0.99 50 / 0.98 50 / 0.98 50 / 0.97
5 Ton
**SEE
NOTE 4
3/8" 3/4" 25 / 0.98 50 / 0.97 50 / 0.95 50 / 0.93 46 / 0.91 NR
1/2" 3/4" 25 / 0.98 50 / 0.97 50 / 0.95 50 / 0.93 50 / 0.91 NR
3/8" 7/8" 25 / 0.99 50 / 0.99 50 / 0.98 50 / 0.97 50 / 0.96 38 / 0.95
1/2" 7/8" 25 / 0.99 50 / 0.99 50 / 0.98 50 / 0.97 50 / 0.96 50 / 0.95
3/8" 1-1/8" ** 25 / 1.00 50 / 1.00 50 / 1.00 50 / 0.99 50 / 0.99 38 / 0.99
1/2" 1-1/8" ** 25 / 1.00 50 / 1.00 50 / 1.00 50 / 0.99 50 / 0.99 50 / 0.99
Notes:
1) Do not exceed 150 ft linear line length.
2) Do not exceed 50 ft vertical separation between indoor and outdoor units.
3) * 3/4" vapor line should only be used for 2 ton systems if outdoor unit is below or at same level as indoor unit to assure proper
oil return.
4) ** 1-1/8" vapor line should only be used for 5 ton systems if outdoor unit is below or at same level as indoor unit to assure prop-
er oil return.
5) Always use the smallest liquid line allowable to minimize refrigerant charge.
6) Applications shaded in light gray indicate capacity multipliers between 0.90 and 0.96 which are not recommended, but are
allowed.
7) Applications shaded in dark gray are not recommended due to excessive liquid or suction pressure drop.

13
Tubing
Table 6B: Refrigerant Line Sizing Chart (Metric Units)
18 SEER2 Variable Speed Outdoor Units
Unit Size
Allowable
Liquid Line
Size
mm [in.]
Allowable
Vapor Line
Size
mm [in.]
Outdoor Unit ABOVE or BELOW Indoor Unit
Equivalent Length (Feet)
< 8 8-15 16-23 24-30 31-38 39-46
Maximum Vertical Separation / Capacity Multiplier
7.0 K W
[2.0 Ton]
*SEE
NOTE 3
6.35 [1/4] 15.88 [5/8] 8 / 1.00 15 / 0.99 10 / 0.98 2 / 0.97 NR NR
7.94 [5/16] 15.88 [5/8] 8 / 1.00 15 / 0.99 15 / 0.98 15 / 0.97 15 / 0.96 15 / 0.95
9.53 [3/8] 15.88 [5/8] 8 / 1.00 15 / 0.99 15 / 0.98 15 / 0.97 15 / 0.96 15 / 0.95
6.35 [1/4] 19.05 [3/4] * 8 / 1.00 15 / 0.99 10 / 0.99 2 / 0.99 NR NR
7.94 [5/16] 19.05 [3/4] * 8 / 1.00 15 / 0.99 15 / 0.99 15 / 0.99 15 / 0.99 15 / 0.98
9.53 [3/8] 19.05 [3/4] * 8 / 1.00 15 / 0.99 15 / 0.99 15 / 0.99 15 / 0.99 15 / 0.98
10.6 KW
[3 Ton]
7.94 [5/16] 15.88 [5/8] 8 / 0.99 15 / 0.97 15 / 0.95 15 / 0.93 11 / 0.91 NR
9.53 [3/8] 15.88 [5/8] 8 / 0.99 15 / 0.97 15 / 0.95 15 / 0.93 15 / 0.91 NR
7.94 [5/16] 19.05 [3/4] 8 / 1.00 15 / 0.99 15 / 0.99 15 / 0.98 11 / 0.97 6 / 0.96
9.53 [3/8] 19.05 [3/4] 8 / 1.00 15 / 0.99 15 / 0.99 15 / 0.98 15 / 0.97 15 / 0.96
12.7 [1/2] 19.05 [3/4] 8 / 1.00 15 / 0.99 15 / 0.99 15 / 0.98 15 / 0.97 15 / 0.96
14.1 K W
[4 Ton]
9.53 [3/8] 19.05 [3/4] 8 / 0.99 15 / 0.98 15 / 0.96 15 / 0.95 15 / 0.93 15 / 0.92
12.7 [1/2] 19.05 [3/4] 8 / 0.99 15 / 0.98 15 / 0.96 15 / 0.95 15 / 0.93 15 / 0.92
9.53 [3/8] 22.23 [7/8] 8 / 1.00 15 / 0.99 15 / 0.99 15 / 0.98 15 / 0.98 15 / 0.97
12.7 [1/2] 22.23 [7/8] 8 / 1.00 15 / 0.99 15 / 0.99 15 / 0.98 15 / 0.98 15 / 0.97
17. 6 K W
[5 Ton]
**SEE
NOTE 4
9.53 [3/8] 19.05 [3/4] 8 / 0.98 15 / 0.97 15 / 0.95 15 / 0.93 14 / 0.91 NR
12.7 [1/2] 19.05 [3/4] 8 / 0.98 15 / 0.97 15 / 0.95 15 / 0.93 15 / 0.91 NR
9.53 [3/8] 22.23 [7/8] 8 / 0.99 15 / 0.99 15 / 0.98 15 / 0.97 15 / 0.96 12 / 0.95
12.7 [1/2] 22.23 [7/8] 8 / 0.99 15 / 0.99 15 / 0.98 15 / 0.97 15 /0.96 15 / 0.95
9.53 [3/8] 28.58 [1-1/8] ** 8 / 1.00 15 / 1.00 15 / 1.00 15 / 0.99 15 / 0.99 12 / 0.99
12.7 [1/2] 28.58 [1-1/8] ** 8 / 1.00 15 / 1.00 15 / 1.00 15 / 0.99 15 / 0.99 15 / 0.99
Notes:
1) Do not exceed 46 meters linear line length.
2) Do not exceed 15 meters vertical separation between indoor and outdoor units.
3) * 19.05mm [3/4 in.] vapor line should only be used for 2 ton systems if outdoor unit is below or at same level
as indoor unit to assure proper oil return.
4) ** 28.58mm [1-1/8 in.] vapor line should only be used for 5 ton systems if outdoor unit is below or at same
level as indoor unit to assure proper oil return.
5) Always use the smallest liquid line allowable to minimize refrigerant charge.
6) Applications shaded in light gray indicate capacity multipliers between 0.90 and 0.96 which are not
recommended, but are allowed.
7) Applications shaded in dark gray are not recommended due to excessive liquid or suction pressure drop.

14
1. Use care in routing tubing and do not kink or
twist. Use a good quality tubing bender on the
vapor line to prevent kinking.
Item Number Description
1Temporary Hanger
2Permanent Hanger
Figure 5: Temporary Hanger and Permanent Hanger
2. Route the tubing using temporary hangers; then
straighten the tubing and install permanent hang-
ers. The tubing must be adequately supported.
3. Isolate the vapor line from the building structure.
If the vapor line comes in contact with inside
walls, ceiling, or flooring, the vibration of the
vapor line in the heating mode will result in noise
inside the structure.
4. Blow out the liquid and vapor lines with dry nitro-
gen before connecting to the outdoor unit and
indoor coil to remove debris that can plug the
expansion device.
Figure 6: Isolate Vapor Line from Building Structure
4.5.1 Important Tubing Installation
Practices
Observe the following when installing correctly sized
type “L” refrigerant tubing between the outdoor unit
and indoor coil:
•Check Table 5 for the correct vapor line size and
liquid line size.
•If a portion of the liquid line passes through a
very hot area where liquid refrigerant can be
heated to form vapor, insulating the liquid line is
required.
•Use clean, dehydrated, sealed refrigeration-grade
tubing.
•Always keep tubing sealed until tubing is in place
and connections are to be made.
•A high-quality biflow filter drier is included with all
R-410A heat pump units and must be installed in the
liquid line upon unit installation.
•When replacing an R-22 system with an R-410A
system and the line set is not replaced, blow out
the lines with dry nitrogen to remove as much of
the remaining mineral oil as possible. Check for low
spots where oil may be trapped and take measures
to drain the oil from those areas.
Figure 7: Debur Cut Tubing Ends
•If tubing has been cut, debur the ends while holding
the tubing in a position to prevent chips from
falling into tubing. Burrs such as those caused by
tubing cutters can affect performance dramatically,
particularly on small diameter liquid lines.
•For best operation, keep tubing run as short as
possible with a minimum number of elbows or bends.
•Locations where the tubing will be exposed to
mechanical damage should be avoided. If it is
necessary to use such locations, the copper
tubing should be protected by a housing to prevent
damage.
ST-A1226-05-00
4.5 Line Set Installation
12
Tubing

15
Figure 8: Slop Vapor Line Toward the Indoor Unit
4.5.2 Relative Location of Indoor and Outdoor Units
ST-A1219-01-01
1
2
3
4.5.2.1 Outdoor Unit Level or Near Level to Indoor Coil Line Set
For applications with the outdoor unit and indoor unit on the same level the following is required:
1. Insulated liquid line in unconditioned space only.
2. Insulated vapor line full length.
3. Vapor line should slope toward the indoor unit. (Reference Figure 8)
4. Follow the proper line sizing, maximum linear and equivalent length, charging requirements, and oil
level adjustments spelled out in this document.
5. Verify at least 5°F [2.8°C] sub-cooling at the indoor unit prior to expansion device.
Item
Number
Descripton
1 Reference Table 6 For Maximum Length Limitations
2 Ideally, Line Set Slopes Away From Outdoor Unit.
Verify Sub-Cooling Prior To Expansion Device,
Insulated Liquid Line In Unconditioned Space For
Long Line Applications.
3Insulated Vapor Line Full Length
Tubing

16
Tubing
4.5.2.2 Outdoor Unit Below Indoor Coil (Long Line Set Applications)
For applications with the outdoor unit below the indoor coil, the following is required:
1. Inverted vapor-line trap (Reference Figure 9)
2. Insulated liquid line in unconditioned space only.
3. Insulated vapor line full length.
4. Follow the proper line sizing, maximum linear and equivalent length, maximum vertical separation,
charging requirements, and oil level adjustments spelled out in this document.
5. Measure pressure at the liquid line service valve and prior to expansion device. Verify that the pressure
drop is not greater than 50 PSI [345 kPa].
6. For elevations greater that 25’ [8 m] a lower subcooling can be expected.
7. Verify there is at least 5ºF [2.8ºC] of liquid subcooling at the indoor coil prior to the expansion device.
ST-A1219-02-01
1
23
4
5
Figure 9: Long Line Liquid Line Routing
Item
Number
Descripton
1Insulated Vapor Line Full Length
2 Inverted Trap Even With Top Of The Coil
3Verify Liquid Subcooling Prior To Expansion Device
In The Cooling Mode
4Insulate Liquid Line In Unconditioned Space For
Long Line Applications
5Reference Table 6 For Maximum Length And.
Vertical Separation Limitations

17
Tubing
4.5.2.3 Outdoor Unit Above Indoor Coil
For applications with the outdoor unit above the indoor coil the following is required:
1. Insulated liquid line in unconditioned space only.
2. Follow the proper line sizing, maximum linear and equivalent length, maximum vertical separation,
charging requirements, and oil level adjustments spelled out in this document.
3. Insulated vapor line full length.
4. Verify at least 5°F [2.8ºC] of liquid subcooling at the outdoor unit prior to expansion device in the heat-
ing mode.
Figure 10: Liquid Line Routing for Unit Installed Above Indoor Coil
Item Number Descripton
1Insulated Vapor Line Full Length
2 Verify Liquid Sub-Cooling At Outdoor Unit Prior To
Expansion Device
3Insulated Liquid Line In Unconditioned Space For
Long Line Application.
4Reference Table 6 For Maximum Length And
Vertical Separation Limitations.

18
Tubing
4.5.3 Tubing Connections
Indoor coils have only a holding charge of dry nitrogen.
Keep all tube ends sealed until connections are to be
made.
1. Use type “L” copper refrigeration tubing. Braze the
connections with the following alloys:
• – Copper to copper, 5% silver minimum
• – Copper to steel or brass, 15% silver minimum
Figure 11: "L" Type Refrigeration Tubing Locations
2. Be certain both refrigerant shutoff valves at the
outdoor unit are closed.
Figure 12: Remove Caps and Schrader Cores
3. Remove the caps and Schrader cores from the
pressure ports to protect seals from heat damage.
Both the Schrader valves and the service valves
have seals that may be damaged by excessive
heat.
Figure 13: Clean Inside Fittings and Outside Tubing
4. Clean the inside of the fittings and outside of the
tubing with a clean, dry cloth before soldering.
Clean out debris, chips, dirt, etc., that enters tub-
ing or service valve connections.
Figure 14: Wrap Valves Before Applying Heat
5. Wrap valves with a wet rag or thermal barrier
compound before applying heat.
Figure 15: Braze the Tubing
6. Braze the tubing between the outdoor unit and
indoor coil. Flow dry nitrogen into a pressure port
and through the tubing while brazing, but do not
allow pressure inside tubing which can result in
leaks. Once the system is full of nitrogen, the
nitrogen regulator should be turned off to avoid
pressuring the system.
Figure 16: Cool the Joint After Brazing
7. A fter brazing, use an appropriate heatsink material
to cool the joint.
8. Reinstall the Schrader cores into both pressure
ports.
Figure 17: Do Allow the Vapor and Liquid Lines to Cross
9. Do not allow the bare vapor line and liquid line
to be in contact with each other. This causes an
undesirable heat transfer resulting in capacity loss
and increased power consumption.

19
Tubing
4.6 Initial Leak Testing
Indoor coils have only a holding charge of dry
nitrogen. Keep all tube ends sealed until connections
are to be made.
The variable speed inverter driven heat pumps are
equipped with an EXV and must be matched to
indoor coils or air-handlers that are also equipped
with EXVs. During shipment, vibration has been
found to move the EXV stem valve to a near closed
position despite being set to a fully open position in
the factory. Prior to leak testing it is recommended to
apply power to the indoor and outdoor units, making
sure there is no call for operation by disconnecting
the EcoNet™ control center or thermostat. By doing
this, the controls will immediately close the EXV's
followed immediately by opening them to the wide
open position, permitting free flow of nitrogen through
the system during the brazing process.
Figure 18: Pressurize Line Set
1. Pressurize line set and coil through service fit-
tings with dry nitrogen to 150 PSIG [1,034 kPa]
(maximum). Close nitrogen tank valve, let sys-
tem sit for at least 15 minutes, and check to see
if the pressure has dropped. If the pressure has
dropped, check for leaks at the line set braze
joints with soap bubbles and repair leak as nec-
essary. Repeat pressure test. If line set and coil
hold pressure, proceed with line set and coil
evacuation (see Sections 4.7 and 4.8 for evacu-
ation and final leak testing).
Figure 19: Insulate Vapor Line
2. The vapor line must be insulated for its entire
length to prevent dripping (sweating) and prevent
performance losses. Closed-cell foam insulation
such as Armaflex and Rubatex®are satisfactory
insulations for this purpose. Use 1/2" [12.7 mm]
minimum insulation thickness. Additional insula-
tion may be required for long runs. The liquid
line must be insulated in any unconditioned
space when long line sets are used and anytime
the liquid line is run through an attic due to hot
temperatures that occur there.
4.7 Evacuation
Figure 20: Evacuate Air and Moisture from System
Evacuation is one of the most important parts of the
entire installation and service procedure. The life
and efficiency of the equipment is dependent upon
the thoroughness exercised by the serviceman when
evacuating air and moisture from the system.
Air or nitrogen in the system increases condensing
temperature and pressure, resulting in increased
power consumption, erratic operation, and reduced
capacity.
Moisture chemically reacts with the refrigerant and oil
to form corrosive acid which attacks the compressor
motor windings and internal parts and which can
result in compressor failure.
3. After the system has been leak-checked and
proven sealed, connect the vacuum pump and
evacuate system to 500 microns and hold 500
microns or less for at least 15 minutes. The
vacuum pump must be connected to both the
high and low sides of the system by connecting
to the two pressure ports. Use the largest size
connections available since restrictive service
connections may lead to false readings because
of pressure drop through the fittings.
ST-A1226-07-00
ST-A1226-06-00
ST-A1226-08-00
WARNING:
Do not use oxygen to purge lines or pressurize
system for leak test. Oxygen reacts violently with
oil, which can cause an explosion resulting in
severe personal injury or death.

20
Figure 21: Open Both Service Valves
4. After adequate evacuation, open both service
valves by removing both brass service valve
caps with an adjustable wrench. Insert a 3/16"
[5 mm] or 5/16" [8 mm] hex wrench into the stem
and turn counterclockwise until the wrench stops.
Figure 22: Connect Gauges
5. If not already connected from evacuation pro-
cess, gauges must be connected at this point to
check and adjust charge.
IMPORTANT: Compressors (especially scroll
type) should never be used to evacuate the air
conditioning system because internal electrical
arcing in near vacuum conditions may result in a
damaged or failed compressor. Never run a scroll
compressor while the system is in a vacuum or
compressor failure will occur.
4.8 Final Leak Testing
After the unit has been properly evacuated and
service valves opened, a halogen leak detector
should be used to detect leaks in the system. All joints
and piping within the outdoor unit, indoor coil, and
interconnecting tubing should be checked for leaks. If
a leak is detected, the refrigerant should be recovered
before repairing the leak. The Clean Air Act prohibits
releasing refrigerant into the atmosphere.
4.9 Control Wiring
4.9.1 EcoNet™Communications
The EcoNetTM enabled (-)A18AZ/(-)P18AZ Series heat
pumps and air conditioners are specifically designed
to be matched with and EcoNetTM enabled air-handler
or gas furnace and the EcoNetTM Control Center.
While they can be controlled by conventional 24
VAC control wiring and a conventional thermostat for
temporary emergency situations until communication
issues are resolved. Unit operates as a single stage
system, and this eliminates many of the advanced
operating and diagnostic features.
4.9.2 EcoNet™Control Center
Installation
The EcoNetTM Control Center should be mounted 4
to 5 feet [1.2 to 1.5 m] above the floor on an inside
wall of the living room or a hallway that has good
air circulation from the other rooms being controlled
by the Control Center. It is essential that there
be free air circulation at the location of the same
average temperature as other rooms being controlled.
Movement of air should not be obstructed by furniture,
doors, draperies, etc. The Control Center should not
be mounted where it will be affected by drafts, hot
or cold water pipes or air ducts in walls, radiant heat
from fireplace, lamps, the sun, T.V. or an outside wall.
See instructions packaged with Control Center for
detailed mounting and installation instructions.
4.9.3 EcoNet™Communication
Wiring Connections
The four 18 AWG low-voltage control wires must be
installed from the EcoNet™ Control Center to the
indoor unit and from the indoor unit to the outdoor
unit. The wire length between the Control Center and
indoor unit should not be greater than 100 feet [30.5
m].
The wire length between the indoor unit and outdoor
unit should not be greater than 125 feet [38.1 m].
Running low-voltage wires in conduit with line voltage
power wires is not recommended. Low-voltage wiring
must be connected to the low voltage terminal block
on the Universal Outdoor Control . The terminal block
can be unplugged from the control board to facilitate
wiring.
•An EcoNet™ communicating heat pump system
consists of these matched components:
•EcoNet™ communicating outdoor unit.
•EcoNet™ communicating air handler or EcoNet™
communicating furnace.
•EcoNet™ Control Center.
WARNING:
Turn off electric power at the fuse box or service
panel before making any electrical connections.
Also, the ground connection must be completed
before making line voltage connections. Failure
to do so can result in electrical shock, severe
personal injury, or death.
Wiring