American Standard TRANE 2TWZ9C Assembly instructions

ALL phases of this installation must comply with NATIONAL, STATE AND LOCAL CODES
IMPORTANT — This Document is customer property and is to remain with this unit. Please return to service information pack upon
completion of work.
Installer’s Guide
3. Avoid locating the unit where condensation and freezing of
defrost vapor may annoy the customer. For instance, installing
the unit under a bedroom, kitchen, or picture window may be
annoying to the customer since condensate and fog will occur
during the defrost cycle.
4. Avoid locating the unit under the eaves or other overhead
structures as sizeable icicles may form and the unit may be
damaged by these falling icicles.
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) and slide unit off of pallet.
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 refer to application bulletin
“Trane XR-APG**-EN” (* denotes latest revision number).
3. The support pad must NOT be in direct contact with any
structure. Unit must be positioned a minimum of 12" from any
wall or surrounding shrubbery to insure adequate airflow.
Clearance must be provided in front of control box (access
panels) and 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. Do not locate unit(s)
close to bedroom(s).
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.
Heat Pumps
2TWZ9C with ComfortLink™II and Charge Assist™
These instructions do not cover all variations in systems nor
provide for every possible contingency to be met in connec-
tion with installation. All phases of this installation must
comply with NATIONAL, STATE AND LOCAL CODES. Should
further information be desired or should particular 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 manufacturer or
seller cannot be responsible for the interpretation of this informa-
tion, nor can it assume any liability in connection with its use.
NOTICE:
Trane has always recommended installing Trane approved
matched indoor and outdoor systems.
The benefits of installing approved matched systems are
maximum efficiency, optimum performance 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.
The Weathertron® Heat Pump has been designed and manufactured
to withstand and operate in severe winter conditions. However,
there are precautionary steps which should be taken at the time of
installation which will help assure the efficient operation of the unit.
It is recommended that these precautions be taken for units
being installed in areas where snow accumulation and
prolonged below freezing temperatures occur.
1. Units should be elevated three (3) to twelve (12) inches above the
pad or rooftop, depending on local weather. This additional
height will allow better drainage of snow and ice (melted during
defrost cycle) prior to its refreezing. This should prevent a build-
up of ice around the unit which occurs when unit is not
elevated. Insure that drain holes in unit base pan are not
obstructed preventing draining of defrost water.
2. If possible, avoid locations that are likely to accumulate
snow drifts. If not possible, a snow drift barrier should be
installed around the unit to prevent a build-up of snow on
the sides of the unit and should be of sufficient distance from
the unit to prevent restriction of airflow to and from the
unit. Also allow for proper maintenance space. The barrier
should be constructed of materials which will blend in with
the building design.
18-BC53D1-4
15 FT. ABOVE UNIT — UNRESTRICTED

© 2007 American Standard Inc. All Rights Reserved 18-BC53D1-4
Installer’s Guide
7. If outdoor unit is mounted above the air handler, maximum lift
should not exceed twenty-five (25) feet (suction line). If air
handler is mounted above condensing unit, maximum lift
should not exceed twenty-five (25) feet (liquid line).
8. Locate and install indoor coil or air handler in accordance with
instruction included with that unit.
C. INSTALLING REFRIGERANT LINES
CAUTION
!
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 ninety (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.
CAUTION
!
In scroll compressor applications, 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 with twenty-five (25) feet of line set.
Final refrigerant charge adjustment is necessary. Use the
Subcooling Charging procedure 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:
Large diameter 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 LINE SERVICE VALVE
The Brass Liquid Line Service Valve is 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).
WARNING
!
Extreme caution should be exercised when opening the Liquid Line
Service Valve. Turn valve stem counterclockwise only until the
stem contacts the rolled edge. (See Figures 3 and 5). No torque is
required. Failure to follow this warning will result in abrupt release
of system charge and may result in personal injury and/or
property damage.
BRASS GAS LINE BALL SERVICE VALVE
The Brass Gas Line 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 Ball 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.
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 re-
moved and a wet rag wrapped around the valve body.
NOTE:
Use care to make sure that no moisture enters pressure tap port,
while wet rag is being used.
NOTE:
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 when
brazing the field line to the 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.
LIQUID LINE SERVICE VALVE
3
BASEPAN
TAB REMOVAL
2

18-BC53D1-4 3
Installer’s Guide
After the brazing operation of refrigerant lines to both the outdoor
and indoor unit is completed, the field brazed connections 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.
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 accom-
plished 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. Blank off vacuum pump and micron gauge, close valves on
manifold gauge set.
NOTE:
DO NOT VENT REFRIGERANT INTO THE ATMOSPHERE.
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.
8. The liquid line shut-off valve can now be opened. Remove shut-
off valve cap. Fully insert hex wrench into the stem and
backout counterclockwise until valve stem just touches rolled
edge (approximately five [5] turns) observing WARNING
statement on page 2. See Figure 3.
9. 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.
10. The gas valve can now be opened. For a ball type gas valve, open
the gas valve by 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 8 and 9 above. See Figure 5.
11. The gas valve is now open for refrigerant flow. Replace valve
stem cap to prevent leaks. Again, these caps MUST BE
REPLACED 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 fifteen (15) feet and/or a different
size than recommended, it will be necessary to adjust system
refrigerant charge upon completion of installation. See unit Service
Facts.
E. ELECTRICAL CONNECTIONS
WARNING
!
When installing or servicing this equipment, ALWAYS exercise
basic safety precautions 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 transmis-
sion 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
ComfortLink™ II control and the indoor unit.
Table 1 – NEC Class II Control Wiring
CAP 1/4 TURN ONLY
COUNTERCLOCKWISE
FOR FULL OPEN
POSITION
VALVE STEM
GAS LINE CONNECTION
UNIT SIDE
OF VALVE
PRESSURE TAP PORT
GAS LINE BALL SERVICE VALVE
4GAS LINE SERVICE VALVE 5
NOTE:
The maximum total cable length for the entire Comfort Control
communicating system is 500 ft. 18 AWG.
7. Mount the ComfortLink™ II control in accordance with
instruction included with the ComfortLink™ II control.
Wire per appropriate hook-up diagram (included in these
instructions).
F. DEFROST CONTROL
The demand defrost control measures heat pump outdoor ambient
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 colder coil
temperature is the difference or delta-T measurement. This delta-T
measurement is representative of the operating state and relative
capacity of the heat pump system. By measuring 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.
FAULT IDENTIFICATION
A fault condition is indicated by the fault LED on the control board
inside the heat pump control box.
In normal operation, the status LED 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.
ComfortLink™ II Control Wiring
WIRE SIZE MAX. WIRE LENGTH
18 AWG 250 FT

418-BC53D1-4
Installer’s Guide
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.)
B
BK
Y2
Y1
O
R
D
W1
W3
G
W2
B
D
B
R
D
X2
Y2
Y1
O
CLII
COMFORT
CONTROL
24VAC HOT
24VAC
Common
DATA
CLII
INDOOR
UNIT
CLII
OUTDOOR
UNIT
FIELD WIRING DIAGRAM
COMMUNICATING INDOOR UNIT – COMMUNICATING OUTDOOR UNIT
NOTE: For non-communicating systems, use
the 24 volt wire harness found with
Installation Guide (BAYACHP024A).
7
DEFROST CONTROL CHECKOUT
Normal operation requires:
a. Status LED on board flashing 1 time/second.
b. 12VDC between D & B.
c. 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.
G. COMPRESSOR START UP
After all electrical wiring is complete, SET THE COMFORTLINK™ II
CONTROL SWITCH 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 ComfortLink™ II control 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
6PIN
IDENTIFICATION

18-BC53D1-4 5
Installer’s Guide
SYSTEM FAULTS
REFRIGERANT CIRCUIT
Head Pressure Too High
Head Pressure Too Low
Suction Pressure Too High
Suction Pressure Too Low
Liquid Refrig. Floodback (TXV)
Liquid Refrig. Floodback
(Cap. Tube)
I.D. Coil Frosting
Compressor Runs
Inadequate or No Cooling/Htg
ELECTRICAL
Compressor & O.D. Fan
Won’t 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
DEFROST
Unit Won’t Initiate Defrost
Defrost Terminates on Time
Unit Icing Up
WHAT TO CHECK MODE
POWER SUPPLY
HIGH VOLTAGE WIRING
COMPRESSOR IOL
RUN CAPACITOR
START CAPACITOR
START RELAY
CONTACTOR CONTACTS
LOW VOLTAGE WIRING
CONTROL TRANSFORMER
THERMOSTAT
CONTACTOR COIL
LOW VOLTAGE FUSE
STUCK COMPRESSOR
INEFFICIENT COMP.
REF. UNDERCHARGE
REF. OVERCHARGE
EXCESSIVE EVAP. LOAD
NONCONDENSABLES
RES. O.D. AIRFLOW
O.D. AIR RECIRCULATION
TXV STUCK OPEN
SUPERHEAT
RES. I.D. AIRFLOW
REF. CIR. RESTRICTIONS
SOV LEAKING
SOV COIL DEFECTIVE
CHECK VALVE LEAKING
*DEFROST RELAY DEF.
DEFROST CONTROL DEF.
C
H
C
H
C
H
C
H
C
H
C
H
C
H
C
H
C
H
C
H
C
H
C
H
C
H
C
H
C
H
C
H
C
H
P
P
P
P
P
P
P
P
P
P
P
P
P
P
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
P
P
P
P
S
S
S
S
P
P
P
P
S
S
P
P
P
P
P
P
P
P
P
P
P
P
P
P
S
S
S
S
S
S
S
S
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
S
S
S
S
S
S
S
P
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
P
P
S
S
S
S
S
S
S
S
S
S
S
S
P
P
P
P
P
P
S
S
S
S
S
S
S
S
S
S
S
P
P
S
S
S
S
S
S
S
S
P
P
P
P
P
P
P
S
S
PP
P
P
C - Cooling H - Heating P - Primary Causes S - Secondary Causes *- 3 Phase Only
TROUBLESHOOTING CHART — WHAT TO CHECK
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 in the
Service Facts.
IMPORTANT:
Perform a final unit inspection to be sure that factory tubing has not
shifted during shipment. Adjust tubing if necessary so tubes do not rub
against each other when the unit runs. Also be sure that wiring
connections are tight and wire routing is secure.
I. ELECTRIC HEATERS
Electric heaters, if used, are to be installed in the air handling
device according to the instructions accompanying the air handler
and the heaters.
J. SEACOAST SHIELD
Units installed within one (1) mile of salt water, including seacoasts
and inland waterways, require the addition of BAYSEAC001
(Seacoast Kit) at the time of installation.
IMPORTANT:
See Limited Warranty information in Use and Care Manual.
K. TROUBLESHOOTING

618-BC53D1-4
Installer’s Guide
NOTE: Outdoor Temperature (ODT) must be between 65°F
and 100°F.
Be sure to set Dip Switches for Line Length and Lift before
entering Charge Assist™ Mode. (See Subcool Charging Table
Corrections for Line Length and Rise in the Service Facts for the
outdoor unit.)
To enter Charge Assist™ Mode, press the MODE button for at
least one (1) second. The on-board LEDs will indicate if the
system is capable of continuing. For a detailed description of on-
board LEDs and their function, see the Charge Assist™ Proce-
dure (18-AC72D1-*) contained in the Outdoor Unit (the
position of the * denotes the latest revision number).
The system will take approximately 12-20 minutes to stabilize
before the charge can be checked by Charge Assist™. Once the
system is stabilized, watch to see which LED turns on next. If the
DIRECTION FOR CHARGE ASSIST™
system charge is correct, the “CHARGED” LED will turn on and
remain on for one (1) hour. Once charged, the system will exit
Charge Assist™ and control will return to the Comfort Control.
If the system charge is low, the “ADD” LED will turn on and
stay on up to one (1) hour or until enough refrigerant is added
to reach the required system charge level and turn on the
“CHARGED” LED.
When the “ADD” LED is on, the charging solenoid output will be
active. This feature works to automatically control refrigerant flow
with BAYCAKT001.
If the system charge is high, the “REC” LED will turn on and the
unit will exit Charge Assist™. You must recover refrigerant from
the system before re-entering Charge Assist™.
For additional information on manual charging, please see the Service Facts shipped with the outdoor unit.
CHARGE ASSIST™ CHARGE ASSIST™ PORT
89

18-BC53D1-4 7
Installer’s Guide
2TWZ9 OUTLINE DRAWING
NOTE: ALL DIMENSIONS ARE IN MM (INCHES).
From Dwg. 21D152635 Rev. 14
MODELS BASE A B C D E F G H J K
2TWZ9030C 4 1267 (49-7/8) 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) 933 (36-3/4)
2TWZ9036C 4 1267 (49-7/8) 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) 933 (36-3/4)
2TWZ9048C 4 1267 (49-7/8) 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) 933 (36-3/4)
2TWZ9060C 4 1267 (49-7/8) 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) 933 (36-3/4)

18-BC53D1-4
Trane
A business of
American Standard Companies
www.trane.com
Trane has a policy of continuous product and product data improvement and it reserves the right to change
design and specifications without notice.
MOUNTING HOLE LOCATION
NOTE: ALL DIMENSIONS ARE IN MM (INCHES).
From Dwg. 21D152637 Rev. 1
NOTE: For model base size,
see table on page 7.
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. ComfortLink™ II control is accurate. Check
against a reliable thermometer. Adjust per
instructions with ComfortLink™ II control ......................... [ ]
11. Is correct speed tap being used?
(Indoor blower motor) ............................................................ [ ]
12. Operate complete system in each mode to
insure safe operation. ............................................................ [ ]
Installer’s Guide
P.I. 08/07