Page 1
▲
WARNING
!
▲
WARNING
!
Relay Panel
BAY24VRPAC52DB
18-HD68D1-3
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
Relay Panel
For use with 24V or communicating
2
indoor unit and 24V
controlled outdoor unit
Zone Panel (optional)
3
Zone Sensor with Display (optional)
4
Zone Sensor (optional)
5
Zone Dampers (optional)
6
* A or T
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.
Section 1. Safety
Table of Contents
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 information, nor can it assume any
liability in connection with its use.
LIVE ELECTRICAL COMPONENTS!
During installation, testing, servicing, and troubleshooting 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.
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
06/12
Page 2
Section 2. General Information
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
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
2.3 Optional Accessories
Sensor Description
ZZSENSAL0400AA Indoor Temperature Sensor
BAYSEN01ATEMPA Outdoor Temperature Sensor
Relay Panel
Relay Panel
NORM
DUAL
Dual Fue
Switch
l
0 SO
V
Y1 Stg1
D
Y2 Stg2
R
B
Data
Hot
Thermosta
Com
and Indoor Unit
W1 Stg1
t
W2 Stg2
W3 Stg3
G
AC System
Fan
BK
RS
HV
PWM
Remote
Hum
Indoor
RS
ac
Hum
Comm
24 V
Sensors
Aux1
Only
ac
Aux1
ODT
Bit Master
24 V
Aux2
ODT
Only
Outdoor
ac
Aux2
24 V
Only
Relay Panel
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 18-HD68D1-3
Page 3
2.5 System Transformer Sizing Guidelines
Indoor Unit Type
Comm
Furnace
OD Unit Type
Communicating Heat Pump 35 35
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.
Comm
Air Handler
24V
Furnace
Minimum Indoor 24V Control Power
Transformer Size, VA*
See Below
24V
Air Handler
Section 3. Installation
Unit Location Considerations
The unit’s rugged design allows installation in closet, attic or other non-condensing locations free from obstructions or other hazards.
Remove Cover
1
Remove cover by grasping at edges and gently
pulling the cover straight towards you. It should
release without much effort.
Mark Mounting Location
2
Mark four holes on the wall using the base as a
template. A level may be used to ensure accuracy.
Relay Pane
l
N
OR
M
DUA
L
Dual Fuel
Switch
0 SOV
Y1 Stg1
Y2 Stg2
W1 Stg1
W2 Stg2
W3 Stg3
G
Fan
BK
PWM
Hum
ac
Hum
24 V
Only
Aux1
ac
Aux1
24 V
Only
Aux2
ac
Aux2
24 V
Only
Relay Panel
D
Data
Thermostat
and Indoor Unit
AC System
HV
NORM
DUAL
Dual Fue
Switch
l
0 SO
V
Y1 Stg1
D
Y2 Stg2
R
B
Data
Hot
Thermostat
Com
and Indoor Unit
W1 Stg1
W2 Stg2
W3 Stg3
G
AC System
Fan
BK
RS
HV
PWM
Remote
Hum
Indoor
RS
ac
Hum
Comm
24 V
Sensors
Aux1
Only
ac
Aux1
ODT
Bitmaster
24 V
Aux2
ODT
Only
Outdoor
ac
Aux2
24 V
Only
Relay Pane
l
R
B
Hot
Com
RS
RS
Indoor
Remote
Sensors
ODT
ODT
Comm
Outdoor
Bit Master
18-HD68D1-3 3
Page 4
▲
CAUTION
!
▲
WARNING
!
Mount Panel
3
DRILL HOLES
1/8” for screws
into studs
3/16” for drywall
anchors
Hum
Hum
Aux1
Aux1
Aux2
Aux2
ac
24 V
Only
ac
24 V
Only
ac
24 V
Only
Bitmaster
Relay Panel
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, enlarge pilot holes to 3/16” for anchors (included with
the relay panel).
Gently tap anchors into the holes.
General Wiring Information
4
LIVE ELECTRICAL COMPONENTS!
During installation, testing, servicing, and troubleshooting 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.
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.
Attach base to wall using four screws provided. Do
not overtighten.
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 Diagrams for specific system applications.
Wires may
enter at
any of 8
locations
Relay Panel
4 18-HD68D1-3
Page 5
t
Co
s
o
B
Data
Hot
Com
DR
B
Dual Fuel
Switch
DUAL
Routing Wires
5
Run wires within the recessed wire “raceway”. Be
sure there is ample length to reach the connectors.
Attaching Wires
6
Using 1/8” blade screwdriver, attach all wires securely to the proper terminals on the Relay Panel.
Refer to the following section for detailed terminal
information.
(See the Field Wiring Diagrams section for common system configurations.)
Route wires into “Raceways”
Data
0 SOV
Y1 Stg1
Y2 Stg2
Thermo
and Indo
R
D
Hot
Securing Wires
7
Secure all wires with the supplied wire ties to ensure that wires are kept in place and not strained.
W1 Stg1
W2 Stg2
W3 Stg3
Fan
G
M
Secure wires with Wire Ties
AC System
HV
Bi
18-HD68D1-3 5
Page 6
Section 4. Terminal Locations and Identification
Refer to the following diagrams for descriptions
of each terminal.
KEY
A
B
C
D
Terminal
Identification
Dual Fuel Switch
Thermostat +
24VAC Input
Optional Sensors
HVAC System
D
A
NORM
Dual Fuel
Switch
0 SOV
Y1 Stg1
Y2 Stg2
W1 Stg1
W2 Stg2
W3 Stg3
G
PWM
BK
Hum
Hum
Aux1
Aux1
Aux2
Aux2
Fan
DUAL
24 Vac
Only
24 Vac
Only
24 Vac
Only
Relay Panel
D R
B
Data
Hot
Thermostat
and Indoor Unit
HVAC System
Comm
Bit Master
Com
B
Indoor
Remote
Sensors
Outdoor
ODT
ODT
RS
RS
C
A
Dual Fuel Switch
Switch Position Description
A
NORM
NORM
DUAL
For HP or conventional
Heat/Cool systems.
DUAL For dual fuel systems.
Dual Fuel
Switch
This switch ships in the NORM position by
default. Refer to the following section for complete Field Wiring Diagrams.
6 18-HD68D1-3
Page 7
DUAL
Thermosta
and Indoor Unit
Switch
V
1
2
For convenience, you may record the color of each wire
used in the blanks provided.
B
Thermostat and Indoor Unit Connections
l
Terminal Name Description Color Used:
D - Data Data
D R
B
B
R - Hot 24 V hot
B - Com 24 V common
Data
Hot
Com
Note: R & B must receive 24 volts from the indoor unit transformer.
Thermostat
and Indoor Unit
m
C
Optional Remote Sensor Connections
Terminal Name Description Color Used:
Remote Indoor
temp sensor
ZZSENSAL0400AA
1 Outdoor temp sensor
BAYSEN01ATEMPA
HVAC System Connections
Second Stage
Compressor
Indoor
Remote
Sensors
ODT
ODT
Outdoor
RS
RS
0 SOV
Y1 Stg1
Y2 Stg2
C
Data
RS
Indoor
Remote
RS
ODT
Outdoor
ODT
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.
1 Wired outdoor temperature sensor must be enabled at the 950 Control.
D
D
Terminal Name Description Color Used:
O - SOV Switch Over Valve
Y1 - Stg1 First Stage Compressor
Y2 - Stg2
W1 - Stg1 First Stage ID Heating
D
W1 Stg1
W2 Stg2
W3 Stg3
Fan
G
PWM
BK
Hum
Hum
Aux1
Aux1
Aux2
Aux2
24 Vac
Only
24 Vac
Only
24 Vac
Only
HVAC System
LEDs
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 ---
*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 control requires a 950 control with software version 2.1 or later
18-HD68D1-3 7
Page 8
DUAL FUEL VARIABLE SPEED GAS FURNACE
DUAL FUEL NON-VARIABLE SPEED GAS FURNACE
DU
DUAL FUEL WITH
VARIABLE SPEED OIL FURNACE
Section 5. Field Wiring Diagrams
DUAL FUEL
TWO STAGE
THERMOSTAT
R
B
D
RELAY
PANEL
COOL/HEAT
-2nd STAGE
24VAC HOT
HEATING 4th STAGE
HEATING 3rd STAGE
COOL/HEAT 1st STAGE
FAN
SOV
24VAC
common
VS MODE -fan
DATA
REMOTE
INDOOR
SENSOR
OUTDOOR
SENSOR
VARIABLE SPEED
GAS FURNACE
Y2
W3
R
W2
W1
Y1
G
O
B
BK
D
RS
RS
ODT
ODT
Y/
Y2
R
W2
W1
Y1/
Y
LO
G
O
B
C
BK
I D
SENSOR
O D
SENSOR
ONE OR TWO STAGE
HEAT PUMP
Y2
R
X2
Y1
O
B
THERMOSTAT
R
B
D
RELAY
PANEL
24VAC HOT
HEATING 3rd STAGE
HEATING 2nd STAGE
COOL/HEAT 1st STAGE
FAN
SOV
24VAC common
DATA
REMOTE
INDOOR
SENSOR
OUTDOOR
SENSOR
Y2
W3
R
W2
W1
Y1
G
O
B
BK
D
RS
RS
ODT
ODT
NON-V.S. ONE
OR TWO STAGE
GAS FURNACE
R
W2
W/
W1
Y
G
B
C
I D
SENSOR
O D
SENSOR
SINGLE STAGE
HEAT PUMP
R
X2
Y
O
B
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.
THERMOSTAT
RELAY
PANEL
COOL/HEAT
2nd STAGE
24VAC HOT
R
HEATING 4th STAGE
HEATING 3rd STAGE
COOL/HEAT 1st STAGE
FAN
SOV
24VAC common
B
VS MODE -fan
DATA
D
REMOTE
INDOOR
SENSOR
OUTDOOR
SENSOR
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.
W3
W2
W1
RS
RS
ODT
ODT
VARIABLE
SPEED
OIL FURNACE
Y2 Y
R
BT
Y1
G
O
B
BK
D
I D
SENSOR
O D
SENSOR
R
R1
W1
YLO
G
O
B
C
BK
OIL BURNER PRIMARY
R1
ONE OR TWO
STAGE HEAT PUMP
Y2
R
X2
Y1
O
B
T
T
Note: Dual fuel switch on Relay Panel must be set to DUAL.
AL FUEL WITH NON-VARIABLE SPEED OIL FURNACE
THERMOSTAT
R
B
D
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.
RELAY
PANEL
24VAC HOT
HEATING 3rd STAGE
HEATING 2nd STAGE
COOL/HEAT 1st STAGE
FAN
SOV
common
24VAC
DATA
REMOTE
INDOOR
SENSOR
OUTDOOR
SENSOR
Y2
W3
R
W2
W1
Y1
G
O
B
BK
D
RS
RS
ODT
ODT
NON-VARIABLE
SPEED
OIL FURNACE
R
BT
W/
W1
Y
G
B
C
OIL BURNER PRIMARY
I D
SENSOR
O D
SENSOR
SINGLE STAGE
HEAT PUMP
R1
R1
R
X2
Y
O
B
T
T
8 18-HD68D1-3
Page 9
HEAT PUMP WITH *AM7 Air Handlers
HEAT PUMP WITH VARIABLE SPEED INDOOR
Non-Communicating Air Handler
HEAT PUMP WITH 2/4TEE3C
HEAT PUMP WITH NON-VARIABLE SPEED INDOOR
Y2
W3
R
W2
W1
Y1
G
O
B
BK
D
RS
RS
ODT
ODT
TWE & 2/4TEE3F
VARIABLE SPEED
AIR HANDLER
Y/
Y2
W3
R
W2
W1
Y1/
LO
Y
G
O
B
BK
I D
SENSOR
O D
SENSOR
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.
RELAY
PANEL
COOL/HEAT 2nd STAGE
HEATING 5th STAGE
24VAC HOT
HEATING 4th STAGE
HEATING 3rd STAGE
COOL/HEAT 1st STAGE
FAN
SOV
24VAC common
VS MODE -fan
DATA
REMOTE
INDOOR
SENSOR
OUTDOOR
SENSOR
HEAT PUMP
ONE OR TWO STAGE
HEAT PUMP
Y2
R
Y1
X2
O
B
THERMOSTAT
R
B
D
RELAY
PANEL
COOL/HEAT 2nd STAGE
HEATING 5th STAGE
24VAC HOT
HEATING 4th STAGE
HEATING 3rd STAGE
COOL/HEAT 1st STAGE
FAN
SOV
24VAC common
DATA
REMOTE
INDOOR
SENSOR
OUTDOOR
SENSOR
Y2
W3
R
W2
W1
Y1
G
O
B
D
RS
RS
ODT
ODT
AIR HANDLER
W3
R
W2
W1
Y
G
O
B
I D
SENSOR
O D
SENSOR
SINGLE STAGE
HEAT PUMP
R
X2
Y
O
B
Communicating Air Handler in 24 Volt Mode
THERMOSTAT
R
B
D
Note: Remove the “R” to “BK” jumper at the low voltage control board.
RELAY
PANEL
COOL/HEAT 2nd STAGE
HEATING 5th STAGE
24VAC HOT
HEATING 4th STAGE
HEATING 3rd STAGE
COOL/HEAT 1st STAGE
FAN
SOV
24VAC common
VS MODE -fan
DATA
REMOTE
INDOOR
SENSOR
OUTDOOR
SENSOR
Y2
W3
R
W2
W1
Y1
G
O
B
BK
D
RS
RS
ODT
ODT
AIR HANDLER
Y2
W3
R
W2
W1
Y1
G
O
B
BK
I D
SENSOR
O D
SENSOR
ONE OR TWO STAGE
HEAT PUMP
Y2
R
Y
X2
O
B
THERMOSTAT
R
B
D
Note: Cut the factory installed "BK" jumper at the indoor unit.
RELAY
PANEL
COOL/HEAT 2nd STAGE
HEATING 5th STAGE
24VAC HOT
HEATING 4th STAGE
HEATING 3rd STAGE
COOL/HEAT 1st STAGE
FAN
SOV
common
24VAC
VS MODE -fan
DATA
REMOTE
INDOOR
SENSOR
OUTDOOR
SENSOR
AIR HANDLER
Y2
W3
R
W2
W1
Y1
G
O
B
BK
D
RS
RS
ODT
ODT
Y2
W3
R
W2
W1
Y1
Yo
G
O
B
BK
I D
SENSOR
O D
SENSOR
ONE OR TWO STAGE
HEAT PUMP
Y2
R
Y
X2
O
B
18-HD68D1-3 9
Page 10
COOLING WITH VARIABLE SPEED INDOOR
THERMOSTAT
COOLING WITH NON-VARIABLE SPEED INDOOR
COOLING WITH 2/4TEE3C
COOLING WITH *AM7 AIR HANDLERS
R
B
D
RELAY
PANEL
COOLING-2nd
HEATING -3rd
24VAC HOT
HEATING -2nd
HEATING -1st
COOLING -1st
FAN
24VAC common
VS MODE -fan
DATA
REMOTE
INDOOR
SENSOR
OUTDOOR
SENSOR
TWO STAGE VS
GAS FURNACE or
VS AIR HANDLER
& ELECTRIC HEAT
Y2
W3
R
W2
W1
Y1
G
O
B
BK
D
RS
RS
ODT
ODT
Y/
Y2
W3
R
W2
W1
Y1/
LO
Y
G
O
B
C
BK
I D
SENSOR
O D
SENSOR
HEAT/COOL
ONE OR TWO STAGE
AIR CONDITIONER
Y2
R*
Y/
Y1
B
THERMOSTAT
R
B
D
RELAY
PANEL
HEATING -3rd
24VAC HOT
HEATING -2nd
HEATING -1st
COOLING -1st
FAN
common
24VAC
DATA
REMOTE
INDOOR
SENSOR
OUTDOOR
SENSOR
Y2
W3
R
W2
W1
Y1
G
O
B
BK
D
RS
RS
ODT
ODT
ONE OR TWO STAGE
GAS FURNACE or
AIR HANDLER &
ELECTRIC HEAT
W3
R
SINGLE STAGE
W2
AIR CONDITIONER
W/
W1
Y
G
B
C
I D
SENSOR
O D
SENSOR
Y
B
Note: Enable "BK" (turn on dehumidifier switch or cut “BK” jumper).
Note: *R is only connected on two-compressor models
Communicating Air Handler in 24 Volt Mode
THERMOSTAT
R
B
D
RELAY
PANEL
COOL/HEAT 2nd STAGE
HEATING 5th STAGE
24VAC HOT
HEATING 4th STAGE
HEATING 3rd STAGE
COOL/HEAT 1st STAGE
FAN
SOV
common
24VAC
VS MODE -fan
DATA
REMOTE
INDOOR
SENSOR
OUTDOOR
SENSOR
Y2
W3
R
W2
W1
Y1
G
O
B
BK
D
RS
RS
ODT
ODT
AIR HANDLER
Y2
W3
R
W2
W1
Y1
G
O
B
BK
I D
SENSOR
O D
SENSOR
ONE OR TWO STAGE
AIR CONDITIONER
Y2
R*
Y
B
THERMOSTAT
R
B
D
RELAY
PANEL
COOLING-2nd
HEATING -3rd
24VAC HOT
HEATING -2nd
HEATING -1st
COOLING -1st
FAN
24VAC
common
VS MODE -fan
DATA
REMOTE
INDOOR
SENSOR
OUTDOOR
SENSOR
Y2
W3
R
W2
W1
Y1
G
O
B
BK
D
RS
RS
ODT
ODT
AIR HANDLER
Y2
W3
R
W2
W1
Y1
Yo
G
O
B
BK
I D
SENSOR
O D
SENSOR
ONE OR TWO STAGE
AIR CONDITIONER
Y2
R*
Y
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.
Note: *R is only connected on two-compressor models
Note: Remove the factory installed "BK" jumper at the indoor unit.
Note: *R is only connected on two-compressor models
10 18-HD68D1-3
Page 11
COOLING WITH NON-VARIABLE SPEED OIL FURNACE
COOLING WITH VARIABLE SPEED OIL FURNACE
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 STAG E
HEATING 4th STAGE
W2
O
R
G
W2
Y1/
Y
LO
Y1
B
ONE OR TWO STAGE
HEAT PUMP
D D
W1
B
C
W3
Y2
COOL/HEAT
-2nd STAGE
BK
VS MODE -fan
Y/
Y2
Y2
BK
THERMOSTAT
R
B
D
O
O
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
VARIABLE
THERMOSTAT
R
B
D
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: *R is only connected on two-compressor models
RELAY
PANEL
COOL/HEAT
2nd STAGE
24VAC HOT
HEATING 4th STAGE
HEATING 3rd STAGE
COOL/HEAT 1st STAGE
FAN
SOV
24VAC
common
VS MODE -fan
DATA
REMOTE
INDOOR
SENSOR
OUTDOOR
SENSOR
W3
W2
W1
RS
RS
ODT
ODT
SPEED
OIL FURNACE
Y2 Y
R
Y1
G
O
B
BK
D
I D
SENSOR
O D
SENSOR
R
W1
Y
G
O
B
BK
ONE OR TWO STAGE
AIR CONDITIONER
R1
LO
C
OIL BURNER PRIMARY
R1
THERMOSTAT
Y2
R*
Y1
B
T
T
R
B
D
RELAY
PANEL
24VAC HOT
HEATING
COOLING
FAN
24VAC common
DATA
REMOTE
INDOOR
SENSOR
OUTDOOR
SENSOR
Y2
W3
R
W2
W1
Y1
G
O
B
BK
D
RS
RS
ODT
ODT
SINGLE STAGE
OIL FURNACE
R
W
Y
G
B
C
I D
SENSOR
O D
SENSOR
SINGLE STAGE
AIR CONDITIONER
R1
Y
B
OIL BURNER PRIMARY
T
R1
T
18-HD68D1-3 11
Page 12
Section 6. LED Indicators
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.
0 SOV
Y1 Stg1
Y2 Stg2
W1 Stg1
W2 Stg2
W3 Stg3
Fan
G
PWM
BK
Hum
Hum
Aux1
Aux1
Aux2
Aux2
24 Vac
24 Vac
24 Vac
Only
Only
Only
D R
B
Data
Hot
Thermostat
and Indoor Unit
HVAC System
Comm
Bit Master
Com
Sensors
Section 7. Troubleshooting
Troubleshooting
Symptom Possible Cause Action
Loss of 24VAC between power (R) and common (B) Check for proper incoming 24VAC power
COMM LED is not
flashing the appropriate number
of devices
Bit Master LED is
off or fluttering
HVAC System
LED is not illuminating when Relay
Panel is calling for
a particular relay
One or more communicating devices is not communicating
• ~12VDC between D & B = Proper communication
• ~16VDC between D & B = Loss of communication
• Less than ~12VDC between D & B = shorted or no power
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)
Control is not calling
Relay Panel failed
Check for open or shorts in field wiring
Evaluate other communicating devices and use
the service facts of that device if not communicating properly
Check for shorted wire between data (D) and
common (B) wires
Check the System Report screen at the control
to verify demand
Verify 24VAC between relay output terminal and
common (B)
**Relay output contains snubber circuits; always
check with a load applied
6200 Troup Highway
Tyler, TX 75707
© 2011 Trane
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.
12 18-HD68D1-3
Loading...