Trane Relay Panel User manual

18-HD68D1-3
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.
These instructions do not cover all variations in systems or provide for every possible contingency to be met in connection with
the installation. 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.
Table of Contents
Section 1. Safety................................................1
Section 2. General Information.........................2
Section 3. Installation........................................3
Section 4. Terminal Locations & Identification .....6
Section 5. Field Wiring Diagrams.....................8
Section 6. LED Indicators ...............................11
Section 7.Troubleshooting.............................12
▲WARNING
!
This information is intended for use by individuals possess-
ing adequate backgrounds of electrical and mechanical
experience. Any attempt to repair a central air conditioning
product may result in personal injury and/or property dam-
age. The manufacturer or seller cannot be responsible for
the interpretation of this information, nor can it assume any
liability in connection with its use.
▲WARNING
!
LIVE ELECTRICAL COMPONENTS!
During installation, testing, servicing, and troubleshoot-
ing of this product, it may be necessary to work with live
electrical components. Failure to follow all electrical safety
precautions when exposed to live electrical components
could result in death or serious injury. 06/12
Installation Guide
Other Installation Guides may be necessary, based on system configuration.
A list of other system components is shown below.
1 Control (required) *ZONE950AC52ZA
2Relay Panel
For use with 24V or communicating
indoor unit and 24V
controlled outdoor unit
3Zone Panel (optional)
4Zone Sensor with Display (optional)
5Zone Sensor (optional)
6Zone Dampers (optional)
Relay Panel
BAY24VRPAC52DB
* A or T
Section 1. Safety

2 18-HD68D1-3
2.4 Specifications
Specification Description
Product Model: BAY24VRPAC52DB
Product: Relay Panel for use with 24V indoor systems
Size: 8.0” width x 9.3” height x 1.9” depth
Storage Temperature: -40° to 175°F, 5% - 95% RH non-condensing
Operating Temperature: -40° to 150°F, 5% - 95% RH non-condensing
Input Power: 24 VAC from HVAC System (Range: 18-32 VAC)
Power Consumption: 4VA* (See the following table for system transformer sizing guidelines.)
Wire usage: Minimum 18 gauge NEC approved control wiring
HVAC System Type Compatible: Standard (gas/electric), Heat Pump, Dual Fuel
Multistage System Compatible: Standard HVAC Systems: 3-stage heating, 2-stage cooling
Heat Pump Systems: 5-stage heating (2-compressor, 3 aux heat), 2-stage cooling
LEDs: 11 green, 1 amber
Communications: 12 VDC
AUX Contacts: 18–30 VAC, 2A max
2.3 Optional Accessories
Sensor Description
ZZSENSAL0400AA Indoor Temperature Sensor
BAYSEN01ATEMPA Outdoor Temperature Sensor
2.2 Contents in Box
The following parts are included in product model
BAY24VRPAC52DB:
1 - Relay Panel cover
1 - Relay Panel base
4 - Mounting screws/anchors
4 - Wire ties
1 - Installation Guide
Aux2
Relay Panel
Bit Master
Comm
HVACSystem
Sensors
Thermostat
and Indoor Unit
Outdoor Remote
Data Hot Com
D R B
Indoor
RS
RS
ODT
ODT
24Vac
Only 24 Vac
Only 24 Vac
Only
Aux2
Aux1
Aux1
Hum
Hum
BK PWM
Fan
G
W3 Stg3
W2 Stg2
W1 Stg1
Y1 Stg1
Y2 Stg2
0 SOV
NORM
DualFuel
Switch
DUAL
Relay Panel
2.1 Overview
The Relay Panel is a wall mounted low voltage
panel that enables the communicating *ZONE950
control to operate with 24 VAC HVAC equipment.
Only three wires are required from the control to
the Relay Panel.
This Relay Panel controls the operation of heating,
cooling, heat pump and dual fuel systems.
For specific wiring applications, see Field Wiring
Diagrams.
*A or T
Relay Panel
Section 2. General Information

18-HD68D1-3 3
Unit Location Considerations
The unit’s rugged design allows installation in closet, attic or other non-condensing locations free from obstruc-
tions or other hazards.
Remove cover by grasping at edges and gently
pulling the cover straight towards you. It should
release without much effort.
Aux2
Relay Panel
Bit Master
Comm
HVAC System
Sensors
Thermostat
and Indoor Unit
Outdoor Remote
Data Hot Com
D R B
Indoor
RS
RS
ODT
ODT
24 Vac
Only 24 Vac
Only 24 Vac
Only
Aux2
Aux1
Aux1
Hum
Hum
BK PWM
Fan
G
W3 Stg3
W2 Stg2
W1 Stg1
Y1 Stg1
Y2 Stg2
0 SOV
NORM
Dual Fuel
Switch
DUAL
Aux2
Relay Panel
Bitmaster
Comm
HVAC System
Sensors
Thermostat
and Indoor Unit
Outdoor Remote
Data Hot Com
D R B
Indoor
RS
RS
ODT
ODT
24 Vac
Only 24Vac
Only 24Vac
Only
Aux2
Aux1
Aux1
Hum
Hum
BK PWM
Fan
G
W3 Stg3
W2 Stg2
W1 Stg1
Y1 Stg1
Y2 Stg2
0 SOV
NORM
Dual Fuel
Switch
DUAL
Relay Panel
Section 3. Installation
Remove Cover
Mark Mounting Location
1
2
Mark four holes on the wall using the base as a
template. A level may be used to ensure accuracy.
Indoor Unit Type
Comm
Furnace
Comm
Air Handler
24V
Furnace
24V
Air Handler
OD Unit Type Minimum Indoor 24V Control Power
Transformer Size, VA*
Communicating Heat Pump 35 35 See Below
Communicating Air Conditioner 35 35
24Volt-Controlled Single Stage Heat Pump 35 40 35 40
24Volt-Controlled Single Stage Air Conditioner 35 40 35 40
24Volt-Controlled 2-Stage Single Compressor Heat Pump 65 75 65 75
24Volt-Controlled 2-Stage Single Compressor Air Conditioner 50 40 50 40
24Volt-Controlled 2-Stage Dual Compressor Heat Pump 50 75 50 75
24Volt-Controlled 2-Stage Dual Compressor Air Conditioner 35 40 35 40
*Note: The VA rating of all 24V field-installed accessories must be added to the above for sizing indoor unit control transformers or the accessories
must be powered separately.
2.5 System Transformer Sizing Guidelines

4 18-HD68D1-3
CAUTION: EQUIPMENT DAMAGE HAZARD - Improper
wiring can lead to equipment damage. Follow the terminal
connection information carefully to ensure the control is
wired properly. After wires are secure, bare wires
MUST NOT touch each other. See the Field Wiring Dia-
grams for specific system applications.
▲
CAUTION
!
Attach base to wall using four screws provided. Do
not overtighten.
Wires may enter the Relay Panel through openings
on each corner and at the center of each side.
Necessary wire lengths should be considered when
determining entry points.
▲WARNING
!
LIVE ELECTRICAL COMPONENTS!
During installation, testing, servicing, and troubleshoot-
ing of this product, it may be necessary to work with live
electrical components. Failure to follow all electrical safety
precautions when exposed to live electrical components
could result in death or serious injury.
Aux2
Relay Panel
Bitmaster
Comm
HVAC System
Sensors
Thermostat
Outdoor Remote
Data Hot Com
D R B
Indoor
RS
RS
ODT
ODT
24 Vac
Only 24 Vac
Only 24 Vac
Only
Aux2
Aux1
Aux1
Hum
Hum
BK PWM
Fan
G
W3 Stg3
W2 Stg2
W1 Stg1
Y1 Stg1
Y2 Stg2
0 SOV
NORM
Dual Fuel
Switch
DUAL
Relay Panel
1/8” for screws
into studs
3/16” for drywall
anchors
DRILL HOLES
Wires may
enter at
any of 8
locations
Mounting to studs: Drill 1/8” pilot holes in the four
locations marked above.
Mounting to drywall:
If mounting to drywall with no studs behind it, en-
large pilot holes to 3/16” for anchors (included with
the relay panel).
Gently tap anchors into the holes.
Mount Panel
General Wiring Information
3
4

18-HD68D1-3 5
Using 1/8” blade screwdriver, attach all wires se-
curely to the proper terminals on the Relay Panel.
Refer to the following section for detailed terminal
information.
(See the Field Wiring Diagrams section for com-
mon system configurations.)
Secure all wires with the supplied wire ties to en-
sure that wires are kept in place and not strained.
Run wires within the recessed wire “raceway”. Be
sure there is ample length to reach the connectors.
Bi
t
m
Co
HVAC System
Thermo
s
and Indo
o
Data Hot
D R
B
KPW
M
Fan
G
W3 Stg3
W2 Stg2
W1 Stg1
Y1 Stg1
Y2 Stg2
0 SOV
Aux2
Relay Panel
Fault
Comm
Bit Master
HVAC System
Sensors
Thermostat
Outdoor Remote
Data Hot Com
DRB
Indoor
RS
RS
ODT
ODT
24 Vac Only 24 Vac
Only 24 Vac
Only
Aux2
Aux1
Aux1
Hum
Hum
BK PWM
Fan
G
W3 Stg3
W2 Stg2
W1 Stg1
Y1 Stg1
Y2 Stg2
0 SOV
NORM
Dual Fuel
Switch
DUAL
Aux2
Relay Panel
Fault
Comm
Bit Master
HVAC System
Sensors
Thermostat
Outdoor Remote
Data Hot Com
DRB
Indoor
RS
RS
ODT
ODT
24 Vac Only 24 Vac
Only 24 Vac
Only
Aux2
Aux1
Aux1
Hum
Hum
BK PWM
Fan
G
W3 Stg3
W2 Stg2
W1 Stg1
Y1 Stg1
Y2 Stg2
0 SOV
NORM
Dual Fuel
Switch
DUAL
Route wires into “Raceways”
Secure wires with Wire Ties
Attaching Wires
Securing Wires
Routing Wires
6
7
5

6 18-HD68D1-3
KEY Terminal
Identification
ADual Fuel Switch
BThermostat +
24VAC Input
COptional Sensors
DHVAC System
Aux2
Relay Panel
Bit Master
Comm
HVAC System
Sensors
Thermostat
and Indoor Unit
Outdoor Remote
Data Hot Com
D R B
Indoor
RS
RS
ODT
ODT
24 Vac Only 24 Vac
Only 24 Vac
Only
Aux2
Aux1
Aux1
Hum
Hum
BK PWM
Fan
G
W3 Stg3
W2 Stg2
W1 Stg1
Y1 Stg1
Y2 Stg2
0 SOV
NORM
Dual Fuel
Switch
DUAL
A
B
DC
Refer to the following diagrams for descriptions
of each terminal.
This switch ships in the NORM position by
default. Refer to the following section for com-
plete Field Wiring Diagrams.
Aux2
Relay Panel
Bit Master
Comm
HVAC System
Sensors
Thermostat
and Indoor Unit
Outdoor Remote
Data Hot Com
D R B
Indoor
RS
RS
ODT
ODT
24 Vac Only 24 Vac
Only 24 Vac
Only
Aux2
Aux1
Aux1
Hum
Hum
BK PWM
Fan
G
W3 Stg3
W2 Stg2
W1 Stg1
Y1 Stg1
Y2 Stg2
0 SOV
NORM
Dual Fuel
Switch
DUAL
A
ADual Fuel Switch
Switch Position Description
NORM For HP or conventional
Heat/Cool systems.
DUAL For dual fuel systems.
Section 4.Terminal Locations and Identification

18-HD68D1-3 7
Aux2
Relay Panel
Bit Master
Comm
HVAC System
Sensors
Thermostat
and Indoor Unit
Outdoor Remote
Data Hot Co
m
D R B
Indoor
RS
RS
ODT
ODT
24 Vac Only 24 Vac
Only 24 Vac
Only
Aux2
Aux1
Aux1
Hum
Hum
BK PWM
Fan
G
W3 Stg3
W2 Stg2
W1 Stg1
Y1 Stg1
Y2 Stg2
0 SOV
NORM
Dual Fuel
Switch
DUAL
C
DHVAC System Connections
Terminal Name Description Color Used:
O - SOV Switch Over Valve
Y1 - Stg1 First Stage Compressor
Y2 - Stg2 Second Stage
Compressor
W1 - Stg1 First Stage ID Heating
W2 - Stg2 Second Stage ID Heating
W3 - Stg3 Third Stage ID Heating
G - Fan Indoor Blower
BK - PWM PWM Signal for indoor
blower modulation
Hum* Humidifier Contact
Hum* Humidifier Contact
Aux 1* Dehumidifier/Ventilation ---
Aux 1* Dehumidifier/Ventilation ---
Aux 2* Dehumidifier/Ventilation ---
Aux 2* Dehumidifier/Ventilation ---
COptional Remote Sensor Connections
Terminal Name Description Color Used:
Remote
Indoor
RS Remote Indoor
temp sensor
ZZSENSAL0400AA
RS
Outdoor
ODT 1 Outdoor temp sensor
BAYSEN01ATEMPA
ODT
BThermostat and Indoor Unit Connections
Terminal Name Description Color Used:
D - Data Data
R - Hot 24 V hot
B - Com 24 V common
Aux2
Relay Panel
Bit Master
Comm
HVAC System
Sensors
Thermostat
and Indoor Unit
Outdoor Remote
Data Hot Com
D R B
Indoor
RS
RS
ODT
ODT
24 Vac Only 24 Vac
Only 24 Vac
Only
Aux2
Aux1
Aux1
Hum
Hum
BK PWM
Fan
G
W3 Stg3
W2 Stg2
W1 Stg1
Y1 Stg
1
Y2 Stg
2
0 SO
V
NORM
Dual Fue
l
Switch
DUAL
B
For convenience, you may record the color of each wire
used in the blanks provided.
Note: R & B must receive 24 volts from the indoor unit transformer.
Note: The Relay Panel uses 5 VDC to obtain temperature feedback from
remote sensors. Do not run these sensors in a wiring bundle that contains
24 volts AC. See remote sensor literature for troubleshooting.
1Wired outdoor temperature sensor must be enabled at the 950 Control.
*Note: Hum & Aux terminals are dry contacts only. Input voltage will need to be
supplied. Refer to humidifier’s installer’s guide. AUX 1 and AUX 2 contact con-
trol requires a 950 control with software version 2.1 or later
Aux2
Relay Panel
Bit Master
Comm
HVAC System
Sensors
Thermostat
and Indoor Unit
Outdoor Remote
Data
Hot Com
D
RB
Indoor
RS
RS
ODT
ODT
24 Vac Only 24 Vac
Only 24 Vac
Only
Aux2
Aux1
Aux1
Hum
Hum
BK PWM
Fan
G
W3 Stg3
W2 Stg2
W1 Stg1
Y1 Stg1
Y2 Stg2
0 SOV
NORM
Dual Fuel
Switch
DUAL
D
LEDs

8 18-HD68D1-3
DUAL FUEL
R
G
Y1
W1
B
24VAC HOT
24VAC common
RELAY
PANEL
DUAL FUEL VARIABLE SPEED GAS FURNACE
FAN
SOV
DATA
COOL/HEAT -
1st STAGE
HEATING -
3rd STAGE
HEATING -
4th STAGEW2
O
R
G
W2
Y1/
YLO Y1
B
ONE OR TWO STAGE
HEAT PUMP
D
W1
TWO STAGE
VARIABLE SPEED
GAS FURNACE
BC
W3
Y2
COOL/HEAT
-2nd STAGE
BK
VS MODE -fan
Y/
Y2 Y2
BK
THERMOSTAT
R
B
D
OO
R
X2
Note: Enable "BK" (turn on dehumidifier switch or cut “BK” jumper).
Note: Dual fuel switch on Relay Panel must be set to DUAL.
Note: Blower delay profiles must be turned off. See indoor unit
service facts for details.
REMOTE
INDOOR
SENSOR
RS
RS
I D
SENSOR
OUTDOOR
SENSOR
ODT
ODT
O D
SENSOR
DUAL FUEL NON-VARIABLE SPEED GAS FURNACE
THERMOSTAT
R
B
D
Note: Dual fuel switch on Relay Panel must be set to DUAL.
R
G
Y1
W1
B
24VAC HOT
24VAC common
FAN
SOV
DATA
COOL/HEAT -
1st STAGE
HEATING -
2nd STAGE
HEATING -
3rd STAGEW2
O
W3
Y2
BK
R
G
W/
W1
W2
YY
B
SINGLE STAGE
HEAT PUMP
O
R
NON-V.S. ONE
OR TWO STAGE
GAS FURNACE
BC
X2
D
RELAY
PANEL
REMOTE
INDOOR
SENSOR
RS
RS
I D
SENSOR
OUTDOOR
SENSOR
ODT
ODT
O D
SENSOR
R
G
Y1
W1
B
24VAC HOT
RELAY
PANEL
24VAC common
DU
AL FUEL WITH NON-VARIABLE SPEED OIL FURNACE
FAN
SOV
DATA
COOL/HEAT -
1st STAGE
HEATING -
2nd STAGE
HEATING -
3rd STAGEW2
O
R
G
YY
B
SINGLE STAGE
HEAT PUMP
NON-VARIABLE
SPEED
OIL FURNACE
BC
W3
Y2
BK
R1
Note: Dual fuel switch on Relay Panel must be set to DUAL.
Note: BT (Bonnet Thermostat) model THT1248 (BAYSEN03ATEMPAA)
required for dual fuel, oil furnace applications.
W/
W1
R
O
OIL BURNER PRIMARY
T
T
R1
BT X2
D
THERMOSTAT
R
B
D
REMOTE
INDOOR
SENSOR
RS
RS
I D
SENSOR
OUTDOOR
SENSOR
ODT
ODT
O D
SENSOR
R
G
Y1
W1 W1
B
24VAC HOT
COOL/HEAT
2nd STAGE
24VAC common
VS MODE -fan
DUAL FUEL WITH VARIABLE SPEED OIL FURNACE
FAN
SOV
DATA
COOL/HEAT -
1st STAGE
HEATING -
3rd STAGE
HEATING -
4th STAGEW2
O
R
G
YLO Y1
B
BK
VARIABLE
SPEED
OIL FURNACE
BC
W3
Y2 Y Y2
BK
R1
Note: Remove the "R" to "BK" jumper at the low voltage control board.
Note: Cut the factory installed "R" to "O" jumper at the LVTB.
Note: Blower delay profiles must be turned off. See indoor unit
service facts for details.
Note: Dual fuel switch on Relay Panel must be set to DUAL.
Note: BT (Bonnet Thermostat) model THT1248 (BAYSEN03ATEMPAA)
required for dual fuel, oil furnace applications.
R
O
O
ONE OR TWO
STAGE HEAT PUMP
OIL BURNER PRIMARY
T
T
R1
BT X2
RELAY
PANEL
D
THERMOSTAT
R
B
D
REMOTE
INDOOR
SENSOR
RS
RS
I D
SENSOR
OUTDOOR
SENSOR
ODT
ODT
O D
SENSOR
Section 5. Field Wiring Diagrams

18-HD68D1-3 9
HEAT PUMP
R
G
Y1
W1
B
24VAC HOT
24VAC common
HEAT PUMP WITH *AM7 Air Handlers
FAN
DATA
SOV
COOL/HEAT -
1st STAGE
HEATING -
3rd STAGE
HEATING -
4th STAGEW2
O
R
G
W1
W2
Y1
B
ONE OR TWO STAGE
HEAT PUMP
AIR HANDLER
W3
HEATING -
5th STAGE
Y2
COOL/HEAT -
2nd STAGE
VS MODE -fan
Y2 Y2
W3
OO
R
X2
B
BK
Note: Cut the factory installed "BK" jumper at the indoor unit.
Yo Y
BK
RELAY
PANEL
D
THERMOSTAT
R
B
D
REMOTE
INDOOR
SENSOR
RS
RS
I D
SENSOR
OUTDOOR
SENSOR
ODT
ODT
O D
SENSOR
HEAT PUMP WITH VARIABLE SPEED INDOOR
Non-Communicating Air Handler
R
G
Y1
W1
B
24VAC HOT
24VAC common
FAN
SOV
COOL/HEAT -
1st STAGE
HEATING -
3rd STAGE
HEATING -
4th STAGEW2
O
R
G
W1
W2
Y1/
YLO Y1
B
ONE OR TWO STAGE
HEAT PUMP
TWE & 2/4TEE3F
VARIABLE SPEED
AIR HANDLER
W3
HEATING -
5th STAGE
Y2
COOL/HEAT -
2nd STAGE
BK
VS MODE -fan
DATA
Y/
Y2 Y2
BK
W3
OO
R
X2
B
RELAY
PANEL
D
THERMOSTAT
R
B
D
Note: Remove the “R” to “BK” jumper at the low voltage control board.
Note: DIP Switches 5 & 6 must be set to OFF on indoor unit.
REMOTE
INDOOR
SENSOR
RS
RS
I D
SENSOR
OUTDOOR
SENSOR
ODT
ODT
O D
SENSOR
R
G
Y1
W1
B
24VAC HOT
24VAC common
HEAT PUMP WITH 2/4TEE3C
Communicating Air Handler in 24 Volt Mode
FAN
SOV
DATA
COOL/HEAT -
1st STAGE
HEATING -
3rd STAGE
HEATING -
4th STAGEW2
O
R
G
W1
W2
Y1 Y
B
ONE OR TWO STAGE
HEAT PUMP
AIR HANDLER
W3
HEATING -
5th STAGE
Y2
COOL/HEAT -
2nd STAGE
VS MODE -fan
Y2 Y2
BK
W3
OO
R
X2
B
Note: Remove the “R” to “BK” jumper at the low voltage control board.
BK
RELAY
PANEL
D
THERMOSTAT
R
B
D
REMOTE
INDOOR
SENSOR
RS
RS
I D
SENSOR
OUTDOOR
SENSOR
ODT
ODT
O D
SENSOR
R
G
Y1
W1
B
24VAC HOT
24VAC common
HEAT PUMP WITH NON-VARIABLE SPEED INDOOR
FAN
SOV
DATA
COOL/HEAT -
1st STAGE
HEATING -
3rd STAGE
HEATING -
4th STAGEW2
O
R
G
W1
W2
YY
B
SINGLE STAGE
HEAT PUMP
AIR HANDLER
W3
HEATING -
5th STAGE
Y2
COOL/HEAT -
2nd STAGE
W3
OO
R
X2
B
RELAY
PANEL
D
THERMOSTAT
R
B
D
REMOTE
INDOOR
SENSOR
RS
RS
I D
SENSOR
OUTDOOR
SENSOR
ODT
ODT
O D
SENSOR

10 18-HD68D1-3
R
G
Y1
W1
B
24VAC HOT
24VAC
common
COOLING WITH VARIABLE SPEED INDOOR
FAN
DATA
COOLING -1st
HEATING -1st
HEATING -2nd W2
O
R
G
W1
W2
Y/
Y1
B
ONE OR TWO STAGE
AIR CONDITIONER
TWO STAGE VS
GAS FURNACE or
VS AIR HANDLER
& ELECTRIC HEAT
BC
W3
HEATING -3rd
Y2
COOLING-2nd
BK
VS MODE -fan
Y/
Y2 Y2
BK
Y1/
YLO
O
R*
W3
D
THERMOSTAT
R
B
D
Note: Enable "BK" (turn on dehumidifier switch or cut “BK” jumper).
RELAY
PANEL
REMOTE
INDOOR
SENSOR
RS
RS
I D
SENSOR
OUTDOOR
SENSOR
ODT
ODT
O D
SENSOR
Note: *R is only connected on two-compressor models
R
G
Y1
W1
B
24VAC HOT
24VAC common
COOLING WITH NON-VARIABLE SPEED INDOOR
FAN
DATA
COOLING -1st
HEATING -1st
HEATING -2nd W2
O
R
G
W/
W1
W2
YY
B
SINGLE STAGE
AIR CONDITIONER
ONE OR TWO STAGE
GAS FURNACE or
AIR HANDLER &
ELECTRIC HEAT
BC
W3
HEATING -3rd
Y2
BK
W3
RELAY
PANEL
D
THERMOSTAT
R
B
D
REMOTE
INDOOR
SENSOR
RS
RS
I D
SENSOR
OUTDOOR
SENSOR
ODT
ODT
O D
SENSOR
R
G
Y1
W1
B
24VAC HOT
24VAC common
FAN
DATA
SOV
COOL/HEAT -
1st STAGE
HEATING -
3rd STAGE
HEATING -
4th STAGEW2
O
R
G
W1
W2
Y1 Y
B
ONE OR TWO STAGE
AIR CONDITIONER
AIR HANDLER
W3
HEATING -
5th STAGE
Y2
COOL/HEAT -
2nd STAGE
VS MODE -fan
Y2 Y2
W3
O
R*
B
Note: First stage blower air flow is set on air handler interface control board.
Note: Remove the “R” to “BK” jumper at the low voltage control.
BK BK
RELAY
PANEL
D
THERMOSTAT
R
B
D
REMOTE
INDOOR
SENSOR
RS
RS
I D
SENSOR
OUTDOOR
SENSOR
ODT
ODT
O D
SENSOR
COOLING WITH 2/4TEE3C
Communicating Air Handler in 24 Volt Mode
Note: *R is only connected on two-compressor models
R
G
Y1
W1
B
24VAC HOT
24VAC
common
COOLING WITH *AM7 AIR HANDLERS
FAN
DATA
COOLING -1st
HEATING -1st
HEATING -2nd W2
O
R
G
W1
W2
Y
B
ONE OR TWO STAGE
AIR CONDITIONER
AIR HANDLER
B
BK
W3
HEATING -3rd
Y2
COOLING-2nd
VS MODE -fan
Y2 Y2
Y1
O
R*
W3
Yo
BK
Note: Remove the factory installed "BK" jumper at the indoor unit.
RELAY
PANEL
D
THERMOSTAT
R
B
D
REMOTE
INDOOR
SENSOR
RS
RS
I D
SENSOR
OUTDOOR
SENSOR
ODT
ODT
O D
SENSOR
Note: *R is only connected on two-compressor models
HEAT/COOL

18-HD68D1-3 11
R
G
Y1
W1
B
24VAC HOT
24VAC common
COOLING WITH NON-VARIABLE SPEED OIL FURNACE
FAN
DATA
COOLING
OIL BURNER PRIMARY
HEATING
W2
O
R
G
W
YY
B
T
T
SINGLE STAGE
AIR CONDITIONER
SINGLE STAGE
OIL FURNACE
BC
W3
Y2
BK
R1
R1
RELAY
PANEL
D
THERMOSTAT
R
B
D
REMOTE
INDOOR
SENSOR
RS
RS
I D
SENSOR
OUTDOOR
SENSOR
ODT
ODT
O D
SENSOR
COOLING WITH VARIABLE SPEED OIL FURNACE
R
G
Y1
W1 W1
B
24VAC HOT
COOL/HEAT
2nd STAGE
24VAC common
VS MODE -fan
FAN
SOV
DATA
COOL/HEAT -
1st STAGE
HEATING -
3rd STAGE
HEATING -
4th STAGEW2
O
R
G
YLO Y1
B
BK
VARIABLE
SPEED
OIL FURNACE
BC
W3
Y2 Y Y2
BK
R1
Note: Remove the "R" to "BK" jumper at the low voltage control board.
Note: Cut the factory installed "R" to "O" jumper at the LVTB.
Note: Blower delay profiles must be turned off. See indoor unit
service facts for details.
R*
O
ONE OR TWO STAGE
AIR CONDITIONER
OIL BURNER PRIMARY
T
T
R1
RELAY
PANEL
D
THERMOSTAT
R
B
D
REMOTE
INDOOR
SENSOR
RS
RS
I D
SENSOR
OUTDOOR
SENSOR
ODT
ODT
O D
SENSOR
Note: *R is only connected on two-compressor models
HEAT/COOL
R
G
Y1
W1
B
24VAC HOT
24VAC common
RELAY
PANEL
COMMUNICATING
FURNACE
COMMUNICATING FURNACE WITH 24V OUTDOOR
24V FROM RELAY PANEL
FAN
SOV
DATA
COOL/HEAT -
1st STAGE
HEATING -
3rd STAGE
HEATING -
4th STAGEW2
O
R
G
W2
Y1/
Y
LO
Y1
B
ONE OR TWO STAGE
HEAT PUMP
D D
W1
BC
W3
Y2
COOL/HEAT
-2nd STAGE
BK
VS MODE -fan
Y/
Y2 Y2
BK
THERMOSTAT
R
B
D
OO
R
X2
Note: Enable "BK" (turn on dehumidifier switch or cut “BK” jumper).
Note: Dual fuel switch on Relay Panel must be set to DUAL.
Note: Blower delay profiles must be turned off. See indoor unit
service facts for details.
REMOTE
INDOOR
SENSOR
RS
RS
I D
SENSOR
OUTDOOR
SENSOR
ODT
ODT
O D
SENSOR

12 18-HD68D1-3
The manufacturer has a policy of continuous product and product data improvement
and it reserves the right to change design and specifications without notice.
Representative-only illustrations included in this document.
6200 Troup Highway
Tyler, TX 75707
© 2011 Trane
Section 7.Troubleshooting
Troubleshooting
Symptom Possible Cause Action
COMM LED is not
flashing the ap-
propriate number
of devices
Loss of 24VAC between power (R) and common (B) Check for proper incoming 24VAC power
One or more communicating devices is not com-
municating
• ~12VDC between D & B = Proper communication
• ~16VDC between D & B = Loss of communication
• Less than ~12VDC between D & B = shorted or no power
Check for open or shorts in field wiring
Evaluate other communicating devices and use
the service facts of that device if not communi-
cating properly
Bit Master LED is
off or fluttering
Loss of 24VAC between power (R) and common (B) Check for proper incoming 24VAC power
Loss of communication
• 0VDC between D & B (shorted or no power)
• Less than ~12VDC between D & B (low level short)
Check for shorted wire between data (D) and
common (B) wires
HVAC System
LED is not illumi-
nating when Relay
Panel is calling for
a particular relay
Control is not calling Check the System Report screen at the control
to verify demand
Relay Panel failed
Verify 24VAC between relay output terminal and
common (B)
**Relay output contains snubber circuits; always
check with a load applied
Section 6. LED Indicators
Aux2
Relay Panel
Bit Master
Comm
HVAC System
Sensors
Thermostat
and Indoor Unit
Outdoor Remote
Data Hot Com
D R B
Indoor
RS
RS
ODT
ODT
24 Vac Only 24 Vac
Only 24 Vac
Only
Aux2
Aux1
Aux1
Hum
Hum
BK PWM
Fan
G
W3 Stg3
W2 Stg2
W1 Stg1
Y1 Stg1
Y2 Stg2
0 SOV
NORM
Dual Fuel
Switch
DUAL
Comm
Communication LED – Amber
• LED on when first powering up
• LED flashes number of communicating com-
ponents in the system.
• (ex. communicating control with relay panel
will equal two flashes)
Bit Master
Bitmaster/Clock Signal LED – Green
• LED on when Clock is working
HVAC System
HVAC System LEDs – Green
• A Green LED will illuminate when the relay is
energized.