American Standard Ameristar 2A7M3018-060A1000A Assembly instructions

© 2005 American Standard Inc. All Rights Reserved
Since the manufacturer has a policy of continuous product
and product data improvement, it reserves the right to
change design and specifications without notice.
11-AC20D1-1
These instructions do not cover all variations in systems
nor provide for every possible contingency to be met in
connection with installation. All phases of this installa-
tion must comply with NATIONAL, STATE AND LOCAL
CODES. Should further information be desired or should par-
ticular problems arise which are not covered sufficiently for the
purchaser’s purposes, the matter should be referred to your
installing dealer or local distributor.
A. GENERAL
▲ WARNING:
This information is intended
for use by individuals possessing adequate backgrounds
of electrical and mechanical experience. Any attempt to
repair a central air conditioning product may result in
personal injury and or property damage. The manufac-
turer or seller cannot be responsible for the interpreta-
tion of this information, nor can it assume any liability in
connection with its use.
NOTE: AMERICAN STANDARD HAS ALWAYS RECOM-
MENDED INSTALLING AMERICAN STANDARD AP-
PROVED MATCHED INDOOR AND OUTDOOR SYSTEMS.
THE BENEFITS OF INSTALLING APPROVED MATCHED
SYSTEMS ARE MAXIMUM EFFICIENCY, OPTIMUM PER-
FORMANCE AND BEST OVERALL SYSTEM RELIABILITY.
Check for transportation damage after unit is uncrated. Report
promptly, to the carrier, any damage found to the unit.
To determine the electrical power requirements of the unit, refer
to the nameplate of the unit. The electrical power available must
agree with that listed on the nameplate.
B. LOCATION AND PREPARATION OF THE UNIT
1. When removing unit from the pallet, notice the tabs on the
basepan. Remove tabs by cutting with a sharp tool as shown in
Figure 2 (see page 2).
2. The unit should be set on a level support pad at least as large
as the unit base pan, such as a concrete slab. If this is not the
application used please reference ALG-APG0*-EN (*latest revi-
sion number).
3. The support pad must NOT be in direct contact with any
structure. Unit must be positioned a minimum of 12" from any
wallorsurroundingshrubberytoinsureadequateairflow. Clear-
ancemustbeprovidedinfrontofcontrolbox(accesspanels)&any
other side requiring service access to meet National Electrical
Code. Also, the unit location must be far enough away from any
structure to prevent excess roof run-off water from pouring
directly on the unit. When choosing the location of the unit(s),
soundtransmissionthrough air and refrigerant linesetshouldbe
taken into consideration. It is recommended to locate unit(s)
away from areas (bedrooms, etc.) where such sound could be
objectionable.
4. The top discharge area must be unrestricted for at least
five (5) feet above the unit.
5. When the outdoor unit is mounted on a roof, be sure the roof
will support the unit’s weight. Properly selected isolation is
recommended to prevent transmission to the building structure.
6. The maximum length of refrigerant lines from outdoor to
indoor unit should NOT exceed sixty (60) feet.
7. If outdoor unit is mounted above the air handler, maximum
lift should not exceed sixty (60) feet (suction line). If air handler
is mounted above condensing unit, maximum lift should not
exceed sixty (60) feet (liquid line).
Condensing Units
INSTALLER'S GUIDE
ALL phases of this installation must comply with NATIONAL, STATE AND LOCAL CODES
5 FT. ABOVE UNIT — UNRESTRICTED
1
Models: 2A7M3018-060A1000A
IMPORTANT — This Document is customer property and is to remain with this unit. Please return to service information pack
upon completion of work.

PAGE 2 Pub. No. 11-AC20D1-1
INSTALLER'S GUIDE
8. Locate and install indoor coil or air handler in accordance
with instruction included with that unit.
NOTE: Refer to “Refrigerant Piping Software” Pub. No.
32-3312-0*, and “Refrigerant Piping Manual” Pub. No.
32-3009-0* (the position of the * denotes latest revision
number).
C. INSTALLING REFRIGERANT LINES
▲
C
A
U
TI
O
N:
If using existing refrigerant lines
make certain that all joints are brazed, not soldered.
Condensing units have provisions for braze connections.
Pressure taps are provided on the service valves of outdoor unit
for compressor suction and liquid pressures.
The indoor end of the recommended refrigerant line sets may be
straight or with a 90 degree bend, depending upon situation
requirements. This should be thoroughly checked out before
ordering refrigerant line sets.
The gas line must always be insulated.
▲
C
A
U
TI
O
N:
Inscrollcompressorapplications,
dome temperatures may be hot. Do not touch top of
compressor, may cause minor to severe burning.
The units are factory charged with the system charge required
when using fifteen (15) feet of rated connecting line. Unit
nameplate charge is the same.
Final refrigerant charge adjustment is necessary. Use the
Charging Information on Page 6 or in the outdoor unit Service
Facts.
1. Determine the most practical way to run the lines.
2. Consider types of bends to be made and space limitations.
NOTE: Largediameter tubing will be very difficult to rebend once
it has been shaped.
3. Determine the best starting point for routing the refrigerant
tubing — INSIDE OR OUTSIDE THE STRUCTURE.
4. Provide a pull-thru hole of sufficient size to allow both liquid
and gas lines.
5. Be sure the tubing is of sufficient length.
6. Uncoil the tubing — do not kink or dent.
7. Route the tubing making all required bends and properly
secure the tubing before making connections.
8. To prevent a noise within the building structure due to
vibration transmission from the refrigerant lines, the following
precautions should be taken:
a. When the refrigerant lines have to be fastened to floor
joists or other framing in a structure, use isolation type hangers.
b. Isolation hangers should also be used when refrigerant
lines are run in stud spaces or enclosed ceilings.
c. Where the refrigerant lines run through a wall or sill, they
should be insulated and isolated.
d. Isolate the lines from all ductwork.
D. SERVICE VALVE OPERATION
BRASS LIQUID AND GAS LINE SERVICE VALVES
The Brass Liquid and Gas Line Service Valves are factory shipped
in the seated position to hold factory charge. The pressure tap
service port (when depressed) opens only to the field brazing side
of the valve when the valve is in the seated position. The liquid
line valve is not a back seating valve (see WARNING below).
▲ WARNIN
G
:
Extreme caution should be ex-
ercised when opening the Liquid and Gas Line Service
Valves. Turn valve stem counterclockwise only until the
stem contacts the rolled edge. (See Figures 3 and 5) No
torque is required.
BRASS GAS LINE BALL SERVICE VALVE
The Brass Gas Line Ball Service Valve is shipped in the closed
position to hold the factory refrigerant charge. The pressure tap
service port (when depressed) opens only to the field brazing side
when the valve is in the closed position.
The Gas Line Service Valve is full open with a 1/4 turn. See
Figure 4.
BRAZING REFRIGERANT LINES
1. Remove lower access cover to access service valves.
2. Before brazing, remove plugs from external copper stub
tubes. Clean internal and external surfaces of stub tubes prior
to brazing.
3. Cut and fit tubing, minimizing the use of sharp 90° bends.
4. Insulate the entire gas line and its fittings.
5. Do NOT allow uninsulated liquid line to come in direct
contact with bare gas line.
BASEPAN TAB REMOVAL
2
3LIQUID LINE SERVICE VALVE

Pub. No. 11-AC20D1-1 PAGE 3
INSTALLER'S GUIDE
6. Precautions should be taken to avoid heat damage to
the pressure tap valve core during brazing. It is recom-
mended that the pressure tap port valve core be removed
and a wet rag wrapped around the valve body.
NOTICE: Use care to make sure that no moisture enters pressure
tap port, while wet rag is being used.
NOTICE: Precautions should be taken to avoid heat damage to
basepan during brazing. It is recommended to keep the flame
directly off of the basepan.
7. Use a Dry Nitrogen Purge and Brazing Alloy without flux
whenbrazing the field line tothe copper factory connection. Flow
dry nitrogen into either valve pressure tap port, thru the tubing
and out the other port while brazing.
8. Braze using accepted good brazing techniques.
LEAK CHECK
IMPORTANT: Replace pressure tap port valve core before
attaching hoses for evacuation.
After the brazing operation of refrigerant lines to both the
outdoor and indoor unit is completed, the field brazed connec-
tions must be checked for leaks. Pressurize through the service
valve ports, the indoor unit and field refrigerant lines with dry
nitrogen to 350-400 psi. Use soap bubbles or other leak-checking
methods to see that all field joints are leak-free! If not, release
pressure; then repair!
SYSTEM EVACUATION
NOTE: Since the outdoor unit has a refrigerant charge, the gas
and liquid line valves must remain closed.
CAP 1/4 TURN ONLY
COUNTERCLOCKWISE
FOR FULL OPEN
POSITION
VALVE STEM
GAS LINE CONNECTION
UNIT SIDE
OF VALVE
CAP
BODY
COOLING
CORE
PRESSURE TAP PORT
HEATING
GAS LINE BALL SERVICE VALVE
1. Upon completion of leak check, evacuate the refrigerant lines
and indoor coil before opening the gas and liquid line valves.
2. Attach appropriate hoses from manifold gauge to gas and
liquid line pressure taps.
NOTE: Unnecessary switching of hoses can be avoided and
complete evacuation of all lines leading to sealed system can be
accomplished with manifold center hose and connecting branch
hose to a cylinder of HCFC-22 and vacuum pump.
3. Attach center hose of manifold gauges to vacuum pump.
4. Evacuate until the micron gauge reads no higher than
350 microns.
5. Close off valve to vacuum pump and observe the micron
gauge. If gauge pressure rises above 500 microns in one (1)
minute, then evacuation is incomplete or system has a leak.
6. If vacuum gauge does not rise above 500 microns in one (1)
minute, the evacuation should be complete.
7. With vacuum pump and micron gauge blanked off, open valve
on HCFC-22 cylinder and charge refrigerant lines and indoor coil
with vapor to tank pressure of HCFC-22 supply.
NOTE: DO NOT VENT REFRIGERANT INTO THE
ATMOSPHERE.
8. Close valve on HCFC-22 supply cylinder. Close valves on
manifold gauge set and remove refrigerant charging hoses from
liquid and gas pressure tap ports.
NOTE: A 3/16" Allen wrench is required to open liquid line
service valve. A 1/4" Open End or Adjustable wrench is required
to open gas line valve. A 3/4" Open End wrench is required to take
off the valve stem cap.
9. The liquid line shut-off valve can now be opened. Remove
shut-off valve cap. Fully insert hex wrench into the stem and
back out counterclockwise until valve stem just touches rolled
edge (approximately five [5] turns) observing WARNING state-
ment on page 2. See Figure 3.
10. Replace liquid service pressure tap port cap and valve stem
cap. These caps MUST BE REPLACED to prevent leaks.
Replace valve stem and pressure tap cap finger tight, then
tighten an additional 1/6 turn.
45
GAS LINE SERVICE VALVE

PAGE 4 Pub. No. 11-AC20D1-1
INSTALLER'S GUIDE
11. The gas valve can now be opened. For a ball type gas valve,
openthegasvalveby removing the shut-off valve cap and turning
the valve stem 1/4 turn counterclockwise, using 1/4" Open End or
Adjustable wrench. See Figure 4. For brass gas line service valve
opening, follow 9 and 10 above. See Figure 5.
12. The gas valve is now open for refrigerant flow. Replace valve
stem cap to prevent leaks. Again, these caps MUST BE RE-
PLACED to prevent leaks. Replace valve stem and pressure tap
cap finger tight, then tighten an additional 1/6 turn. See Figure 4.
If refrigerant lines are longer than 15 feet and/or a different size
than recommended, it will be necessary to adjust system refriger-
ant charge upon completion of installation. See page 6 or the unit
Service Facts.
E. ELECTRICAL CONNECTIONS
▲ WARNIN
G
:
When installing or servicing
this equipment, ALWAYS exercise basic safety precau-
tions to avoid the possibility of electric shock.
1. Power wiring and grounding of equipment must comply with
local codes.
2. Power supply must agree with equipment nameplate.
3. Install a separate disconnect switch at the outdoor unit.
4. Ground the outdoor unit per local code requirements.
5. Provide flexible electrical conduit whenever vibration trans-
mission may create a noise problem within the structure.
6. The use of color coded low voltage wire is recommended to
simplify connections between the outdoor unit, the thermostat
and the indoor unit.
Table 1 — NEC Class II Wiring
FAULT IDENTIFICATION
A fault condition is indicated by the flashing light on the defrost
control inside the heat pump control box.
In normal operation, the defrost control light will flash once each
second. If the light is flashing more than once per second or not
at all, refer to the service manual for that unit.
PIN IDENTIFICATION (See Figure 6)
1. TEST_COMMON (Shorting any of the other pins to this pin
causes the function of the other pin to be executed. Leaving this
pin open results in the normal mode of operation.)
2. TST = Test (Shorting TEST_COMMON to this pin speeds up
all defrost board timings.)
3. FRC_DFT = Forced Defrost (Short TEST_COMMON to this
pin for two (2) seconds to initiate a forced defrost. Remove the
short after defrost initiates.)
DEFROST CONTROL CHECKOUT
Normal operation requires:
a LED on board flashing 1 time/second.
b. 24V AC between R & B
c. 24V AC between Y & B with unit operating
d. Defrost initiation when FRC_DFT pin is shorted to
TEST_COMMON pin.
If a defrost control problem is suspected, refer to the service
information in control box.
▲ WARNIN
G
:
Do NOT connect 24 VAC to T1
(ODS-A) terminal. ODS-A thermistor WILL BE BLOWN.
G. COMPRESSOR START-UP
After all electrical wiring is complete, SET THE THERMOSTAT
SYSTEMSWITCH IN THE OFF POSITION SO COMPRESSOR
WILL NOT RUN, and apply power by closing the system main
disconnect switch. This will activate the compressor sump heat
(where used). Do not change the Thermostat System Switch
until power has been applied for one (1) hour. Following this
procedure will prevent potential compressor overload trip at the
initial start-up.
FRC_DFT
TEST_COMMON
TST
7. Table 1 defines maximum total length of low voltage wiring
from outdoor unit, to indoor unit, and to thermostat.
8. Mount the indoor thermostat in accordance with instruction
included with the thermostat. Wire per appropriate hookup
diagram (included in these instructions).
F. DEFROST CONTROL
The demand defrost control measures heat pump outdoor ambi-
ent temperature with a sensor located outside the outdoor coil. A
second sensor located on the outdoor coil is used to measure the
coil temperature. The difference between the ambient and the
coldercoiltemperatureisthe difference or delta-T measurement.
This delta-T measurement is representative of the operating
state and relative capacity of the heat pump system. By measur-
ing the change in delta-T, we can determine the need for defrost.
The coil sensor also serves to sense outdoor coil temperature for
termination of the defrost cycle.
6PIN IDENTIFICATION
24 VOLTS
WIRE SIZE MAX. WIRE LENGTH
18 AWG 150 FT
16 AWG 225 FT.
14 AWG 300 FT.

Pub. No. 11-AC20D1-1 PAGE 5
INSTALLER'S GUIDE
TYPICAL FIELD WIRING DIAGRAMS
Notes:
1. Be sure power supply agrees with equipment nameplate.
2. Power wiring and grounding of equipment must comply with local codes.
3. Low voltage wiring to be No. 18 AWG minimum conductor.
4. ODT-B must be set lower than ODT-A.
5. If outdoor thermostats (ODT) are not used, connect W1 to W2 and W3.
6. N/A to programmable thermostat.
LEGEND
FACTORY WIRING
FIELD WIRING
H. OPERATIONAL AND CHECKOUT PROCEDURES
Final phases of this installation are the unit Operational and
Checkout Procedures which are found in this instruction on
page 8. To obtain proper performance, all units must be operated
and charge adjustments made in accordance with procedures
found on page 6 and in the Service Facts.
I. ELECTRIC HEATERS
Electric heaters, if used, are to be installed in the air handling
device according to the instructions accompanying the air han-
dler and the heaters.
J. OUTDOOR THERMOSTAT
An outdoor thermostat TAYSTAT250B may be field installed.
For data, see wiring diagram attached to unit and instruction
sheet packaged with outdoor thermostat.
K. SEACOAST SALT SHIELD
BAYSEAC001 (Seacoast Kit) is available for application on units
installed within one mile of salt water, including seacoasts and
inland waterways.
REFRIGERANT CIRCUIT
Liquid Pressure Too High
Liquid Pressure Too Low
Suction Pressure Too High
Suction Pressure Too Low
Liquid Refrig. Floodback TXV System
I.D. Coil Frosting
Compressor Runs Inadequate or No Cooling
ELECTRICAL
Compressor & O.D. Fan Do Not Start
Compressor Will Not Start But O.D. Fan Runs
O.D. Fan Won’t Start
Compressor Hums But Won’t Start
Compressor Cycles on IOL
I.D. Blower Won’t Start
SYSTEM FAULTS
P - Primary Causes S - Secondary Causes
P
P
P
S
S
PS
S
S
S
S
P
S
S
S
P
P
P
S
S
S
S
S
S
S
P
P
P
S
P
P
S
S
S
P
P
P
P
P
P
P
P
P
P
S
S
S
S
P
P
PP
P
S
S
PSPSS S S S
S
S
P
P
P
P
P
S
P
P
POWER SUPPLY
HIGH VOLTAGE WIRING
COMPR. IOL
RUN CAPACITOR
START CAPACITOR
START RELAY
CONTACTOR CONTACTS
LOW VOLTAGE WIRING
CONTROL TRANSFORMER
CONTACTOR COIL
LOW VOLTAGE FUSE
STUCK COMPRESSOR
INEFFICIENT COMPRESSOR
REFRIGERANT UNDERCHARGE
REFRIGERANT OVERCHARGE
EXCESSIVE EVAP. LOAD
NONCONDENSABLES
RESTRICTED O.D. AIRFLOW
O.D. AIR RECIRCULATION
TXV STUCK OPEN
SUPERHEAT
RESTRICTED I.D. AIRFLOW
REF. CIRCUIT RESTRICTIONS
O.D. FAN SPEED SWITCH
TROUBLESHOOTING CHART — WHAT TO CHECK
L. TROUBLESHOOTING

PAGE 6 Pub. No. 11-AC20D1-1
INSTALLER'S GUIDE
SUBCOOLING CHARGING IN COOLING ABOVE 55°F OD AMBIENT
R-22 SUBCOOLING CHARGING TABLE
LIQUID
TEMP.
(°F)
DESIGN SUBCOOLING VALUES (°F)
8101214
LIQUID LINE PRESSURE (psi)
45 89 93 96 100
50 98 102 105 109
55 107 111 115 119
60 117 121 126 130
65 128 132 137 141
70 139 144 148 153
75 151 156 161 166
80 163 168 174 179
85 176 182 187 193
90 190 196 202 208
95 205 211 217 223
100 220 226 233 239
105 236 243 249 256
110 253 260 267 274
115 271 278 285 293
120 289 297 305 313
125 309 317 325 333
AmericanStandardhasalwaysrecommended installingAmerican
Standard approved matched indoor and outdoor systems.
All 13 SEER Ameristar™ split systems are ARI rated with only
TXV indoor systems.
The benefits of installing approved indoor and outdoor split
systems are maximum efficiency, optimum performance and
the best overall system reliability.
The following charging methods are therefore prescribed for
systems with indoor TXVs.
1. Subcooling (in the cooling mode) is the only recommended
method of charging above 55°F ambient temperatures.
2. For best results - the indoor temperature should be kept
between 70°F to 80°F. Add system heat if needed.
3. At start-up, or whenever charge is removed or added, the
system must be operated for a minimum 20 minutes to
stabilize before accurate measurements can be made.
4. Measure Liquid Line Temperature and Refrigerant Pres-
sure at service valves.
5. Determine total refrigerant line length, and height (lift) if
indoor section is above the condenser.
6. Determinethe Design Subcool Charging Temperaturefrom
the unit nameplate.
7. Locatethisvalueinthe appropriate columnoftheSubcooling
Charging Table. Locate your liquid line temperature in the
left column of the table, and the intersecting liquid line
pressure under your nameplate subcool value column. Add
refrigerant to raise the pressure to match the table, or
removerefrigerant tolowerthepressure. Again, wait20 min-
utes for the system conditions to stabilize before adjusting
charge again.
8. When system is correctly charged, you can refer to System
Pressure Curves (in Service Facts) to verify typical performance.
SUBCOOL CHARGING TABLE CORRECTIONS FOR LINE LENGTH AND RISE
60
50
40
30
25 Add 5 psig to Subcool Charging Table Pressure
20
15 Use Design Subcool Value from Table
10
0Subtract 5 psig from S.C. Table Pressure
10 20 25 30 40 60 80
TOTAL REFRIGERANT LINE LENGTH (FEET)
REFRIGERANT LINE LIFT (FEET)

Pub. No. 11-AC20D1-1 PAGE 7
INSTALLER'S GUIDE
From Dwg. 21D153074 Rev. 10
2A7M3 OUTLINE DRAWING
NOTE: ALL DIMENSIONS ARE IN MM (INCHES).
MODELS BASE FIG. A B C D E F G H J K
2A7M3018A 2 2 651 (25-5/8) 724 (28-1/2) 651 (25-5/8) 5/8 1/4 127 (5) 57 (2-1/4) 181 (7-1/8) 44 (1-3/4) 457 (18)
2A7M3024A 2 2 832 (32-3/4) 724 (28-1/2) 651 (25-5/8) 3/4 5/16 137 (5-3/8) 65 (2-5/8) 210 (8-1/4) 57 (2-1/4) 457 (18)
2A7M3030A 3 2 832 (32-3/4) 829 (32-5/8) 756 (29-3/4) 3/4 5/16 137 (5-3/8) 86 (3-3/8) 210 (8-1/4) 79 (3-1/8) 508 (20)
2A7M3036A 3 2 832 (32-3/4) 829 (32-5/8) 756 (29-3/4) 7/8 3/8 137 (5-3/8) 86 (3-3/8) 210 (8-1/4) 79 (3-1/8) 508 (20)
2A7M3042A 4 1 841 (33-1/8) 946 (37-1/4) 870 (34-1/4) 7/8 3/8 152 (6) 98 (3-7/8) 219 (8-5/8) 86 (3-3/8) 508 (20)
2A7M3048A 4 1 1045 (41-1/8) 946 (37-1/4) 870 (34-1/4) 1-1/8 3/8 152 (6) 98 (3-7/8) 219 (8-5/8) 86 (3-3/8) 508 (20)
2A7M3060A 4 1 1045 (41-1/8) 946 (37-1/4) 870 (34-1/4) 1-1/8 3/8 152 (6) 98 (3-7/8) 219 (8-5/8) 86 (3-3/8) 508 (20)

Pub. No. 11-AC20D1-1
P.I. 9/05
INSTALLER'S GUIDE
Technical Literature - Printed in U.S.A.
American Standard Inc.
Troup Highway
Tyler, TX 75707-9010
MOUNTING HOLE LOCATION Note: All Dimensions Are In MM (Inches).
NOTE:
For model base size,
see table on page 7.
From Dwg. 21D152989 Rev. 0
CHECKOUT PROCEDURE
After installation has been completed, it is recommended that the entire system be checked against the following list:
1. Refrigerant Line, Leak checked...................... [ ]
2. Suction Lines and Fittings
properly insulated ........................................... [ ]
3. Have all Refrigerant Lines been secured and
isolated properly? ........................................... [ ]
4. Have passages through masonry been
sealed? If mortar is used, prevent mortar
from coming into direct contact with
copper tubing.................................................. [ ]
5. Verify tightness of all electrical connects ........ [ ]
6. Observe outdoor fan during on cycle for
clearance and smooth operation .................... [ ]
7. Indoor coil drain line drains freely.
Pour water into drain pan ............................... [ ]
8. Supply registers and return grilles
open and unobstructed................................... [ ]
9. Return air filter installed.................................. [ ]
10. Thermostat thermometer is accurate.
Check against a reliable thermometer.
Adjust per instructions with thermostat........... [ ]
11. Is correct speed tap being used?
(Indoor blower motor) ..................................... [ ]
12. Operate complete system in each mode
to insure safe operation. ................................. [ ]