Trane ACONT900AC43UA User manual

Air Conditioning Procedures
Service Guide
Communicating Residential
Comfort Systems
FirstEdition
© 2010 Trane Inc.
All rights reserved. No part of this book
may be reproduced, in any form or by
any means, without permission in
writing from the publisher.
Produced and printed in the USA
A Comprehensive Reference for Service of Communicating
Residential Air Conditioning, Heat Pump & Gas Furnace Systems
1.0

Air Conditioning Procedures
We appreciate your feedback.....
We value your opinion. If you feel this service guide can be improved in some way, please
give us your thoughts. Simply email your opinion to [email protected]. You may also
write in the space below, tear out this page and mail it to:
Trane Company
Attn: Loran Dailey
6200 Troup Hwy.
Tyler, TX 75707
Comments
Name:
Address:
Email:
Phone# Pub#034-3457-01

Air Conditioning Procedures
We appreciate your feedback.....
Name:
Address:
Email:
Phone# Pub# 034-3457-01
Comments
We value your opinion. If you feel this service guide can be improved in some way, please
give us your thoughts. Simply email your opinion to [email protected]. You may also
write in the space below, tear out this page and mail it to:
Trane Company
Attn: Loran Dailey
6200 Troup Hwy.
Tyler, TX 75707

Cautions & Warnings
A 1
SAFETYHAZARD
THIS INFORMATION IS INTENDED FOR USE BY
INDIVIDUALSPOSSESSINGADEQUATEBACKGROUNDS
OFELECTRICALANDMECHANICALEXPERIENCE.ANY
ATTEMPT TO REPAIR ACENTRALAIR CONDITIONING
PRODUCTMAYRESULTINPERSONALINJURYAND OR
PROPERTYDAMAGE.THEMANUFACTURERORSELLER
CANNOTBERESPONSIBLEFORTHEINTERPRETATION
OF THIS INFORMATION, NOR CAN IT ASSUME ANY
LIABILITYINCONNECTION WITHITSUSE.
WARNING
!
!WARNING
!WARNING
!WARNING
!WARNING
!WARNING
FIREOREXPLOSIONHAZARD
FAILURE TO FOLLOW THE SAFETY WARNINGS EXACTLY
COULDRESULTINSERIOUSPERSONALINJURY,PROPERTY
DAMAGE,ORDEATH.IMPROPERSERVICINGCOULDRESULT
INDANGEROUSOPERATION,SERIOUSPERSONALINJURY,
PROPERTYDAMAGE,ORDEATH.
SERVICEPROCEDURESHAZARD
BODILY INJURY CAN RESULT FROM HIGH VOLTAGE
ELECTRICAL COMPONENTS, FAST MOVING FANS,AND
COMBUSTIBLE GAS. FOR PROTECTION FROM THESE
INHERENT HAZARDS DURING INSTALLATION AND
SERVICING, THE ELECTRICAL SUPPLY MUST BE
DISCONNECTED AND THE MAIN GAS VALVE MUST BE
TURNEDOFF.IFOPERATINGCHECKSMUSTBEPERFORMED
WITH THE UNIT OPERATING, IT IS THE TECHNICIAN’S
RESPONSIBILITY TO RECOGNIZE THESE HAZARDS AND
PROCEEDSAFELY.
Throughout this manual there are procedures where voltage may be
present and gas or refrigerant system checks may be required. Read all
cautions and warnings on this page before proceeding.
Voltage Hazard
Disconnect power to the unit before removing the
blower door. Allow a minimum of 10 seconds for IFC
power supply to discharge to 0 volts. Failure to follow
this warning could result in property damage, personal
injury or death.
CARBONMONOXIDEPOISONINGHAZARD
FAILURE TO FOLLOW THE SERVICEAND/ OR PERIODIC
MAINTENANCE INSTRUCTIONS FOR THE FURNACE AND
VENTINGSYSTEM,COULDRESULTINCARBONMONOXIDE
POISONINGORDEATH.
!WARNING
FIREOREXPLOSIONHAZARD
SHOULDOVERHEATINGOCCUR,ORTHEGASSUPPLYFAIL
TO SHUT OFF, SHUT OFF THE GAS VALVE TO THE UNIT
BEFORESHUTTINGOFFTHEELECTRICALSUPPLY.FAILURE
TOFOLLOWTHISWARNINGCOULDRESULTINPROPERTY
DAMAGE,PERSONALINJURY,ORDEATH.
!CAUTION
Safety Hazard
Sharp Edge Hazard
Be careful of sharp edges on equipment or any cuts
made on sheet metal while installing or servicing.
Personal injury may result.
Where there is no complete return duct system, the
return connection must be run full size from the furnace
to a location outside the utility room, basement, attic,
or crawl space.
Do NOT install return air through the back of the furnace
cabinet.
Do NOT installreturnair throughthe sideof thefurnace cabinet
on horizontal applications.
NOTE: Minimum return air temperature is 55°F.
!CAUTION
CONTAINS REFRIGERANT!
SYSTEMCONTAINS OILAND REFRIGERANT UNDERHIGH
PRESSURE. RECOVER REFRIGERANT TO RELIEVE
PRESSUREBEFOREOPENINGSYSTEM.
Failure to follow proper procedures can result in
personal illness or injury or severe equipment damage.
LABELINGWIRES!
LABEL ALL WIRES PRIOR TO DISCONNECTION WHEN
SERVICING CONTROLS. WIRING ERRORS CAN CAUSE
IMPROPERANDDANGEROUSOPERATION.VERIFYPROPER
OPERATIONAFTERSERVICING.
!CAUTION
!CAUTION
BURNHAZARD
DONOTTOUCHIGNITER.ITIS EXTREMELYHOT.

Cautions & Warnings
A 2

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(A/T)CONT900AC43UA Installer Guide
4 Heat/3 Cool/ Heat Pump
Communicating Programmable 3-Wire Hookup
Introduction........................................................................................................................................ 3
Product specifications ................................................................................................................... 3
Installation.......................................................................................................................................... 3
When installing this product .......................................................................................................... 3
Location......................................................................................................................................... 4
Selecting Comfort Control location ............................................................................................... 4
Sub-base installation ..................................................................................................................... 4
Wiring............................................................................................................................................ 5
Mounting Comfort Control on sub-base......................................................................................... 6
Initial power-up .................................................................................................................................. 6
Power-upsequence ....................................................................................................................... 6
Discovery mode ............................................................................................................................ 6
Communicating indoor unit - Communicating outdoor unit ........................................................... 7
Communicating indoor unit - Single stage cooling unit ................................................................. 7
Adjusting real time clock .................................................................................................................. 7
Setting calendar and time ............................................................................................................. 7
Installer setup (ISU) ........................................................................................................................... 8
Entering installer setup .................................................................................................................. 8
Operation: Using the Comfort Control .......................................................................................... 18
System and fan settings .............................................................................................................. 18
Fan settings................................................................................................................................. 18
LED indication ............................................................................................................................. 18
Filter indication............................................................................................................................ 18
Pre-programmed ......................................................................................................................... 18
Alert code numbers ..................................................................................................................... 18
Equipment damage hazard. Minimum compressor off-time is bypassed during installer
System test ..................................................................................................................................19
System checkout ............................................................................................................................. 19
Installer system test..................................................................................................................... 19
Advanced features........................................................................................................................... 19
Adjustable continuous air flow ..................................................................................................... 19
Control response rate .................................................................................................................. 20
Cycle rate .................................................................................................................................... 20
Auto changeover ......................................................................................................................... 20
Communicating Controller
Section A

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Setpoint deadband ...................................................................................................................... 21
Backlit display ............................................................................................................................. 21
Filter reminders ........................................................................................................................... 21
Fan selections ............................................................................................................................. 21
Screen locked.............................................................................................................................. 21
Installer system tests ................................................................................................................... 21
Default factory settings................................................................................................................ 21
Wait indicator .............................................................................................................................. 22
Calibrate indoor temperature....................................................................................................... 22
Calibrate outdoor temperature .................................................................................................... 22
Outdoor temperature sensor ....................................................................................................... 22
Humidification.................................................................................................................................. 22
Indoor humidification control ....................................................................................................... 22
Frost control ................................................................................................................................ 22
Dehumidification ............................................................................................................................. 22
Integrated temperature and humidity control (ITHC)................................................................... 22
Droop ............................................................................................................................................23
Comfort-R™delay .........................................................................................................................23
Dehumidificationairflow .................................................................................................................23
Proprietaryhumidity control...........................................................................................................23
Special heat pump features ............................................................................................................ 23
Auxiliary heat lockout temperature..............................................................................................23
Compressor heat lockout temperature ........................................................................................ 23
Operation in heat mode............................................................................................................... 24
Defrost heater balance point control ........................................................................................... 24
Operation in emergency heat mode ............................................................................................ 24
Heat pump with fossil fuel heat (dual fuel) and outdoor temperature sensor .............................. 24
Troubleshooting guide ................................................................................................................... 25

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(A/T)CONT900AC43UA Installer Guide
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Table 1
Introduction
The(A/T)CONT900AC43UA isacommunicatingpro-
grammable Comfort Control (See Table 1) that sup-
ports single-stage or multi-stage heat/cool and heat
pump applications. It is a wall mounted, low voltage
(24VAC)communicatingComfort Control with backlit
LCD and a touch screen display. Room temperature
is maintained by controlling the operation of heating,
cooling,heat pump, and dual fuel systems viadigital,
two-way communications. The Comfort Control will
communicatewithandidentifyallComfortLink™IIcom-
ponents in the system. It is easily manually config-
ured via the user friendly Installer Setup menu. The
ComfortControlfeatureincludes separateheatingand
cooling setpoints, selectable auto or manual
changeover,menudriven7-day programming,adjust-
able filter reminders, and outdoor temperature sens-
ing. Setup selections and diagnostics are stored in-
definitelyinthe ComfortControl’snonvolatilememory,
eliminatingthe need for battery backup.
Product specifications
Power source: 18-30 VAC, Class II, 50/60 Hz
Storage range: -30°F to 150°F, 5% to 90% RH non-
condensing
Operating temperature range: 0°F to 120°F, 5% to
90% RH non-condensing
System mode: Heat, Cool, Auto, Emergency Heat,
and Off
Fan mode: On, Auto and Circ
Cooling setpoint temperature range: 60°F to 99°F,
1°F resolution
Heating setpoint temperature range: 50°F to 90°F,
1°Fresolution
Indoortemperature display range:40°Fto 99°F,
Outdoortemperature displayrange:-40°F to127°F
Indoor humidity display range: 0% to 99%, 1% reso-
lution
Minimum cycle off time delay: Compressor, 5 min-
utes. Heat, 0 minutes.
The comfort control contains a Lithium battery which
may contain Perchlorate material.
DuetoStateLawin California,the followingstatement
isrequired:
PerchlorateMaterial-specialhandlingmayapply. See
www.dtsc.ca.gov/hazardouswaste/perchlorate
Installation
When installing this product
Step 1
Read these instructions carefully. Failure to follow
these instructions may damage the product or cause
ahazardous condition.

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Communicating Programmable 3-Wire Hookup
(A/T)CONT900AC43UA Installer Guide
Step 2
Check the ratings given in the instructions and on
the product to make sure the product is suitable for
your application.
Step 3
Installermust beatrained, experienced service tech-
nician.
Step 4
After completing installation, use these instructions
to check out the product operation.
WARNING
Voltage Hazard. Can cause electrical shock or
equipment damage. Disconnect power before
beginning instructions.
Figure 1
Selecting Comfort Control location
Do not install the Comfort Control where it can be
affected by
• Drafts or dead spots behind doors and in
corners.
• Hot or cold air from ducts.
• Radiant heat from sun or appliances.
• Concealed pipes and chimneys.
• Unheated (uncooled) areas such as an outside
wall behind the Comfort Control.
Sub-base installation
The Comfort Control can be mounted horizontally
on the wall or on a two inch by four inch wiring box.
Positionsub-base horizontally on thewallor on a two
inch by four inch wiring box.
Step 1
Turn OFF all power to heating and cooling equip-
ment.
Step 2
If an existing Comfort Control is being replaced:
a.)Removeexisting Comfort Control from thewall.
b.)Disconnect wires from existing control, one at
a time. Be careful not to allow wires to fall back
into wall.
c.) As each wire is disconnected, record wire color
and terminal marking.
d.)Discard or recycle old Comfort Control.
Step 3
Separate the Comfort Control from the sub-base to
expose mounting holes.
Step 4
Positionand level thesub-base wallplate (forappear-
ance only.) The Comfort Control functions properly
even when not level.
Location
Install the Comfort Control about five feet (1.5m)
above the floor in an area with good circulation at
average temperature (See Figure 1.)

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Communicating Programmable 3-Wire Hookup
Step 5
Use a pencil to mark the mounting holes.
Step 6
Remove the sub-base from the wall and drill two 3/
16” holes in the wall (if drywall) as marked.
Forfirmermaterialsuchasplaster,drilltwo7/32”holes.
Gentlytapanchors(provided)intothedrilledholesuntil
flush with the wall.
Step 7
Positionthesub-baseover theholes, pullingthe wires
through the wiring opening.
Step 8
Insert the mounting screws in the holes and tighten.
Wiring
Allwiring must comply with local electrical codesand
ordinances. See Figures 2 and 3 wiring diagrams
for specific equipment applications. Refer to Table
2 for terminal designations.
Figure 2
Field wiring diagram, Communicating indoor unit - Communicating outdoor unit
Figure 3
Field wiring diagram, Communicating indoor unit - Single stage cooling unit
WARNING
Voltage Hazard. Can cause electrical shock or
equipment damage. Disconnect power before
beginning instructions.
Note:
Themaximumcablelength fortheentireComfortControl com-
municating system is 500 feet 18 AWG. The maximum dis-
tance of any single cable from a transformer is 250 feet 18
AWG.
Table 2

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Communicating Programmable 3-Wire Hookup
(A/T)CONT900AC43UA Installer Guide
Step 1
Loosen the terminal screws on the sub-base. Insert
wires into the terminal block next to the loosened
screw (See Figure 4.)
Figure 4
Step 2
Securelytighten each terminal screw.
Step 3
Push excess wire back in the hole.
Step 4
Plugthe holeinthe wall withnonflammable insulation
tohelppreventdrafts fromadverselyaffecting Comfort
Controloperation.
Mounting Comfort Control on sub-base
Step 1
Align the terminal screw block with the pins on the
back of the Comfort Control.
Step 2
Push the Comfort Control straight onto the wallplate
(See Figure 4.)
Step 3
Perform installation of all other system equipment.
Step 4
Turn ON power to the heating and cooling equip-
ment.
Initial power-up
Power-up sequence
ThecommunicatingComfortControl willcommunicate
andidentifyall communicatingcomponents inthesys-
tem.
Discovery mode
DiscoverymodebeginswhenthecommunicatingCom-
fort Control is first installed and power is connected.
For communicating equipment, the Comfort Control
automaticallyconfigures theequipmenttype, number
ofstages, cycle rates for eachstageand compressor
stageratios based on the information it received dur-
ingDiscovery mode.
While in Discovery mode, the LED indicator located
in the upper right corner of the Comfort Control will
be illuminated.
All discovered values will be saved into memory. If
a communicating device goes missing (Err 89) or
changes in value (Err 126) the error will be broad-
cast to the Comfort Control screen (restoring com-
munications will clear this error or see ISU 0706 to
reset the system configuration.)
The communicating Comfort Control can be reset
(ISU0710) to factory default settings.
Note: ISU 0706 Will force a reinitialization without af-
fectingpresets. ISU 0710will reseteverythinginclud-
ing custom programs and presets.
Important: Use 18-gauge color-coded Comfort Control cable for proper
wiring. Shielded cable is not typically required. Keep this wiring at least
one foot away from large inductive loads such as Electronic Air Cleaners,
motors, line starters, lighting ballasts, and large distribution panels. Failure
to follow there wiring practices may introduce electrical interference (noise)
whichcancauseerraticsystemoperation. AllunusedComfortControlwire
to be grounded at indoor unit chassis ground only. Shielded cable may be
required if the above wiring guidelines cannot be met. Ground the shield
only to the system chassis.

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(A/T)CONT900AC43UA Installer Guide
4 Heat/3 Cool/ Heat Pump
Communicating Programmable 3-Wire Hookup
Ifno equipment is connectedduring theAuto-Discov-
ery process, the system mode will be stuck at “OFF”
andno equipment will run.
To changethe default/discoverysettings, enter thein-
staller Setup menu (See Table 4, Pages 9-17) and
select the desired item.
OnlyISU settingswith an “E”will beAuto-Discovered.
Manually changing an ISU setting to an option other
than“E” disablesDiscovery modeforthat ISUsetting.
See Table 3 for default cycle rate settings.
Table 3
Communicating indoor unit - Communicating
outdoor unit
For a fully communicating system, the communicat-
ing Comfort Control will automatically configure the
indoorandoutdoorequipment configurationand cycle
rates for each stage (See Figure 2.)
Communicating indoor unit - Single stage
cooling unit
For a partially communicating system, the commu-
nicating Comfort Control will automatically config-
ure the indoor equipment configuration and cycle
rates for each stage (See Figure 3.)
The outdoor equipment configuration will default to
a single stage cooling unit.
Adjusting real time clock
Setting calendar and time
Locate and remove the tab labeled “Remove” in the
lower left corner of the Comfort Control back. The
tab must be removed to activate the real time clock.
(See Figure 5.)
Figure 5
If the system is not powered, the real time clock bat-
tery life is approximately 20 weeks.
The Comfort Control is designed to automatically
keep the current time and day in memory for up to
ten years under normal use once calendar is set.
When the Comfort Control is powered, the display is
ready for the calendar date to be entered (See Fig-
ure6, next page)
Note: Clock accuracy is +/- 1 minute per month

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TCONT900AC43UA Installer’s Guide
4 Heat/3 Cool/ Heat Pump
Communicating Programmable 3-Wire Hookup
(A/T)CONT900AC43UA Installer Guide
Figure 6
Installer setup (ISU)
The Comfort Control works with many different sys-
tem types. The installer can use the Installer Setup
menu to change factory settings to customize instal-
lations(SeeTable4.)
Entering installer setup
Follow these steps to enter the Installer Setup:
Step 1
Be sure the Comfort Control is powered. If neces-
sary,presstheDonekey toreturn tothe homescreen.
Step 2
Press and release the system key.
Step 3
Press and hold the two blank keys on either side of
the center key for approximately five seconds until
screen changes (See Figure 7.)
Step 4
Release the two blank keys when the screen on the
ComfortControl matches the screen inFigure8 (See
Figure 8.)
Figure 7
Figure 8
Step 5
SeeFigure 8 to review how the Comfort Controlkeys
are used during Installer Setup (See Table 4, Pages
9-17) for the Installer Setup numbers and settings.

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(A/T)CONT900AC43UA Installer Guide
4 Heat/3 Cool/ Heat Pump
Communicating Programmable 3-Wire Hookup
Note:
Manually changing an ISU setting to an option other than “E”
disablesDiscovery modefor thatISU setting. Ifpower is lost,
allcustom settings areretainedin thememory.
Step 6
Press the Done key to exit the Installer Setup.
Table 4. Installer Setup Menu.

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(A/T)CONT900AC43UA Installer Guide
Table 4. Installer Setup Menu Continued.
Nohumidity option availableif 3 is
selected
Note:If single stageis configured,ODU will runLow Stage,
but ID airflow ill be 100%. If 3-Three Stage is configured,
therewill be anErr89 on statbut unit willrun.
For3 stagefurnace:
Option1 = Highstage heat only
Option2 = Mediumand high stageheatonly For modulating furnace:
Option1 = Highstage heat
Option2=Modulating
Option3= 40% or100%- No modulation
Note:If anything elseis configured, otherthan
“E1”,thenthe blower willnotrun in coolingwith
afurnace but continuous fan andheat will op-
erate blower okay/
Note:Auto discovered lowstage airflow for20
SEER:
2 Ton=50%
3Ton= 55%
4Ton= 50%
5Ton= 65%

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(A/T)CONT900AC43UA Installer Guide
4 Heat/3 Cool/ Heat Pump
Communicating Programmable 3-Wire Hookup
Table 4. Installer Setup Menu Continued.
Note:E1 = Autodiscovered w/com ODU
E0= Auto discoveredw/o comODU

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(A/T)CONT900AC43UA Installer Guide
Table 4. Installer Setup Menu Continued.
Note: Y2 counter only with Phase 2 product (serial date
code0904) if heatdemand is satisfiedby Y2- reset timer
HPwith EH =0 (no lockout)
DualFuel = 40degrees default
(Range is 5 - 60)
Note: “0” is not an option with Dual Fuel (must
havea lockouttemp configured)
DualFuel = 50degrees default
Must have option 2 selected in
ISU0350.
(Range is 45-65 with 40 degree de-
faultis selected inISU0350). (A5 de-
gree deadband is enforced between
comp lockout and aux heat lockout)
Note: Watch for cool air complaints during de-
frost if aux heat lockout is configured. Also be
awareof ISU0361, 362and 363.
Note:For phase 2 factory
setting= 0 -disabled.
(phase 2 = serial data code 0904)