Trane Tracer UC400 Installation and operating instructions

SSAAFFEETTYY WWAARRNNIINNGG
Only qualified personnel should install and service the equipment The installation, starting up, and servicing of heating, ventilating, and air-conditioning
equipment can be hazardous and requires specific knowledge and training Improperly installed, adjusted or altered equipment by an unqualified person
could result in death or serious injury When working on the equipment, observe all precautions in the literature and on the tags, stickers, and labels that
are attached to the equipment
April 2020 BBAASS--SSVVXX4488HH--EENN
Installation, Operation, and Maintenance
Tracer®UC400/UC400–B
Programmable Controllers
For Blower Coil, Fan Coil, and Unit Ventilator

©2020 Trane BAS-SVX48H-EN
Introduction
NNoottee:: Specific reference to either UC400 or UC400–B is made throughout this document. All
other content cited in this document about the UC400 is referred to as UUCC440000 CCoonnttrroolllleerr.
The UC400/UC400-B is a multi-purpose, programmable (or application-specific controller) that
provides direct-digital zone temperature control The controller can operate as a stand-alone
device or as part of a building automation system (BAS) Communication between the controller
and a BAS occurs on an open standard with inter-operable protocols used in Building
Automation and Control Networks (BACnet®) Programming is done by means of the Tracer® TU
service tool
This guide provides installation and configuration information for the UC400 Controller with
specific operation description for Blower Coil, Fan Coil, and Unit Ventilation
Refer to the Resource section for documentation related to concepts discussed throughout this
manual
Copyright
This document and the information in it are the property of Trane, and may not be used or
reproduced in whole or in part without written permission Trane reserves the right to revise this
publication at any time, and to make changes to its content without obligation to notify any
person of such revision or change
Trademarks
All trademarks referenced in this document are the trademarks of their respective owners
Agency istings and Compliance
The European Union (EU) Declaration of Conformity is available from your local Trane® office
Revision History
Corrected Face/Bypass terminations in Figure 6, p 23 and Figure 12, p 29

BAS-SVX48H-EN 3
BACnet Protocol 6
BACnet® Testing Laboratory (BTL) Certification 6
Specifications and Dimensions 7
Device Connections 9
Additional Components 11
Water, Discharge, and Outdoor Air Temperature Sensors 11
Binary Input Switching Devices 11
Zone Temperature Sensors 11
Valve and Damper Actuators 12
Zone Humidity Sensor 12
CO2Sensor 12
Expansion Modules 12
Typical Applications and Terminations 13
Binary Inputs 14
BI1; Occupancy 14
BI2; Condensate Overflow 14
BI3; Low Coil Temp Detection 15
BI4; Frost Detection 15
BI5; Fan Status 15
Analog Inputs 15
Ground Terminals 15
AI1; Space Temperature 15
AI2; Space Temperature Local Setpoint 15
AI3; Local Fan Mode Input 16
AI4; Discharge Air Temperature Sensor 16
AI5; Entering Water Temperature 16
Universal Inputs 16
UI1; Relative Humidity or CO2Sensor 16
UI2; Outdoor Air Temperature 17
Binary Outputs 17
Override Outputs 17
Wiring Requirements 17
UC400 Wiring Diagrams 19
UC400–B Wiring Diagrams 25
Wiring Installation 31
Connecting Wires to Terminals 31
BACnet MS/TP Link 31
MAC Address 31
BACnet Device ID 31
Table of Contents

4BAS-SVX48H-EN
BACnet Networks, With or Without Tracer SC Controller 31
Without a Tracer SC Controller 31
With a Tracer SC Controller 31
BACnet MS/TP Link Wiring 32
Power Supply 33
Transformer Recommendations 33
Wiring Requirements 33
Connecting 24 Vac Secondary Wires 34
Power On Check 35
LED Description, Activities, and Troubleshooting 36
Sequence of Operation 39
Power-up Sequence 39
Random Start 39
Occupancy Modes 39
Occupied Mode 39
Unoccupied Mode 40
Occupied Standby Mode 40
Occupied Bypass Mode 40
Timed Override Control 40
Zone Temperature Control 40
Discharge Air Tempering 42
Heating or Cooling Mode 42
Auto-Changeover Entering Water Temperature Sampling Function 42
Fan Operation 43
Manual Fan Speed Control 43
Auto Fan Operation; 1–, 2–, 3–Speed 43
Single Zone VAV 43
Exhaust Control 44
Valve Operation 45
Modulating Valve Operation 45
3–Wire Floating Point Valve Calibration 45
2–Position Valve Operation 45
Face/Bypass Damper Operation 45
Modulating Outdoor/Return Air Damper 45
ASHRAE Cycle 1 Conformance 46
ASHRAE Cycle 2 Conformance 46
Economizing (Free Cooling) 47
Outdoor Air Damper Control With Varying Fan Speed 47
CO2-Based Demand Controlled Ventilation 48
Fan Operating at Multiple Speeds or Single-Zone VAV Control 48
DX Cooling Operation, 1 or 2 Circuits 49
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BAS-SVX48H-EN 5
Heat Pump Operation, 1 or 2 Circuits 50
Defrost Operation 50
Electric Heat Operation 50
Dehumidification Operation 50
Unit Protection Strategies 51
Smart Reset 51
Low Coil Temperature Protection 51
Condensate Overflow 51
Fan Status 51
Fan Off Delay 52
Filter Maintenance Timer 52
Freeze Avoidance 52
Freeze Protection, Discharge Air Temperature Low Limit 52
Output Testing 53
Diagnostics 53
Diagnostic Types 53
Diagnostic Generated by the UC400 54
Operational Causes and Diagnostics 57
Configuration and Maintenance 60
Settings for CO2-Based Demand Controlled Ventilation 63
Resources 67
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6BAS-SVX48H-EN
BACnet Protocol
The Building Automation and Control Network (BACnet®) protocol is ANSI/ASHRAE Standard
135 This standard allows building automation systems or components from different
manufacturers to share information and control functions BACnet® provides building owners
the capability to connect various types of building control systems or subsystems together for
many uses Multiple vendors can use this protocol to share information for monitoring and
supervisory control between systems and devices in a multi-vendor interconnected system The
BACnet® protocol defines standard objects (data points) called BACnet® objects Each object has
a defined list of properties that provide context information about that object In addition,
BACnet® defines a number of application services that are used to interact with objects in a
BACnet® device
BACnet®Testing aboratory (BT ) Certification
The UC400 Controller supports the BACnet communication protocol and has been designed to
meet the requirements of the application-specific control profile For more details, refer to the
BTL web site at www bacnetinternational org The UC400 Controller supports the following
equipment when used as an application-specific unit:
• Blower Coils
• Fan Coils
• Unit Ventilators
• WSHP (Variable Speed)
• VAV

BAS-SVX48H-EN 7
Specifications and Dimensions
Table 1. UC400/UC400–B Specifications
Storage
Temperature: –48°F to 203°F (–44°C to 95°C)
Relative Humidity: Between 5% and 95% (non-condensing)
Operating
Temperature: –40°F to 158°F (–40°C to 70°C)
Humidity: Between 5% and 95% (non-condensing)
Input Power: 20.4–27.6 Vac (24, ±15% nominal), 50Hz to 60Hz, 24 VA
(24 VA plus binary output loads for a maximum of 12 VA for each binary output)
Mounting Weight of
Controller:
Supporting mounting surface: must be 0.80 lb. (.364 kg)
Environmental Rating
(Enclosure):
NEMA 1
Altitude: 6,500 ft. maximum (1,981 m)
Installation: U.L. 840: Category 3
Pollution: U.L. 840: Degree 2
Housing Material:(a) Polycarbonate/ABS Blend
UV protected
U.L. 94-5VA flammability rating
Mounting: UC400: Mounts on EN 50 022 - 35 X 15 DIN rail.
UC400–B: Pre-mounted.
Agency Listing
UL916 PAZX, Open Energy Management Equipment
UL94-5V, Flammability
CE Marked
FCC Part 15, Subpart B, Class B Limit
AS/NZS CISPR 22:2006
VCCI V-3/2008.04
ICES-003, Issue 4:2004
Communications BACnet®MS/TP, supports BACnet Protocol ASHRAE 135-2004 and Meets BACnet Testing Laboratory (BTL) as an Application
Specific Controller (ASC) Profile Device
(a) Not applicable for the UC400-B model.

8BAS-SVX48H-EN
Figure 1. UC400 and UC400–B Dimensions
5.65 in. (143.5 mm)
(*8 Units)
4.00 in.
(101.6 mm)
2.37 in. (60.1 mm)
*DIN Standard 43 880, Built-in Equipment for Electrical Installation. Overall Dimensions and Related Mounting Dimensions.
1.89 in. (48 mm)
1.79 in. (45.4 mm)
14 Pin AMP
BO4
BO5
24VAC
GND BO6
BO7 BI2 BI2 BI3 BI3 AI5
GND
24VAC GND
14 13 12 11 10 9 8 7 6 5 4 3 2 1
J9
USB
J10
3 Pin
Mini
AMP
Service
J18
3 Pin
Mini
AMP
BO7
24VAC
J14 - JST
BO6
0
5
3
8
0
5
3
8
1
5
3
8
0
1
5
3
8
0
Address
AIP4 GND
J2
4 Pin Phoenix
24VAC GND 24VAC GND 24VAC
GND
J15 J17
P1
PI1 PI2
J4
BO9
GND
24VAC BO8
J16
BO1
24VAC
BO2
24VAC
BO3
24VAC
AMP
Phoenix
PhoenixPhoenix
24VDC
GND
Comm +
Comm -
5 pin Phoenix
J8
BACnet
4 Pin Phoenix
J13
AIP3 GND
AIP2
24VAC
AIP1
GND
J1
6 pin Phoenix
J6
AOP2
GND
Phoenix
J5
AOP1
GND
Phoenix
+ - + -
IMC
J12 - AMP
J11 - AMP
BI1 BI1
J3
Phoenix
UIP1
GND
UIP2
GND
24VDC
+
-Gnd 24VDC
1 2 3 4 5 6 1 2 3 4 5 6 123 4
123 4 12 3 4
1
23
4
1
23
4
1 2 3
12
12
21 345
12
1
2
2 1
3
4
56
6.125 in. (155.58 mm)
4.500 in.
(114.30 mm)
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BAS-SVX48H-EN 9
Device Connections
The following table provides details of the hardware termination configuration options The
hardware terminations are pre-configured for proper equipment operation for blower coil/fan coil
applications
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Table 2. Connections
Connection Quantity Types Range Notes
Analog input
(AI1 to AI5) 5
Temperature 10 kΩ thermistor
AI1 to AI4 can be configured for timed override capability.
Setpoint 189 Ω to 889 Ω
Resistive 100 Ω to 100 kΩ Typically used for fan speed switch.
Universal input
(UI1 and UI2) 2
Linear 0–20 mA
These inputs may be configured to be thermistor or resistive
inputs, 0–10 Vdc inputs, or 0–20 mA inputs.
Linear 0–10 Vdc
Temperature 10 kΩ thermistor
Setpoint 189 Ω to 889 Ω
Resistive 100 Ω to 100 kΩ
Binary Open collector/dry contact Low impedance relay contacts recommended.
Pulse Solid state open collector Minimum dwell time is 25 milliseconds On and 25 milliseconds
Off.
Binary input
(BI1 to BI3)(a) 324 Vac detect The UC400 controller provides the 24 Vac required to drive the
binary inputs when using the recommended connections.
Binary output
(BO1 to BO3)
(a)
3UC400:Relay
• 2.88 A @24 Vac C pilot
duty
• Gen Purpose
–10 A max up 277 Vac
–10 A max up to 30 Vdc
• Motor Duty
–1/3 hp @ 125 VAC
(7.5 A max)
–1/2 hp @ 277 VAC
(7.5 A max)
Power needs to be wired to the binary output. All outputs are
isolated from each other and from ground or power.
Note: Ranges given are per contact.
Other
Ranges UC400–B:TRIAC 24 Vac Powered
Binary output
(BO4 to BO9)(a) 6 TRIAC
•UC400: 0.5 A max @24-
277 Vac, resistive and pilot
duty
•UC400–B: 24 Vac
Powered
Use for modulating TRIAC. User determines whether closing high
side (providing voltage to the grounded load) or low side
(providing ground to the power load).
Note: Ranges given are per contact and power comes from
TRIAC SUPPLY circuit.

10 BAS-SVX48H-EN
Table 2. Connections (continued)
Connection Quantity Types Range Notes
Analog output/
binary input
(AO1/BI4 and
AO2/BI5)
2
Linear output 0–20 mA
Each termination must be configured as either an analog output
or binary input.
Linear output 0–10 Vdc
Binary input Dry contact
PWM output 80 Hz signal @ 15 Vdc
Pressure inputs
(PI1 and PI2) 2
3-wire 0–5 in H2O•UC400: Pressure inputs supplied with 5 volts of power.
Designed for Kavlico™ pressure transducers.
•UC400–B: Used as a binary input for condensate on WSHP.
Overall Point
Total 23
(a) Do Not mix Class 1 and Class 2 voltage wiring in an enclosure or on a controller without an approved barrier between the wiring.
DDeevviiccee CCoonnnneeccttiioonnss

BAS-SVX48H-EN 11
Additional Components
The UC400 Controller requires the use of additional components for monitoring and proper
control of associated equipment The use of specific components is dependent on the type of
application
NNoottee:: Additional components are not included with the UC400 Controller.
Water, Discharge, and Outdoor Air Temperature Sensors
Temperature sensors must be Trane 10 kΩ (at 25°C) thermistors Entering water and discharge air
inputs can use a sealed temperature sensor (part numbers 4190 1100 and 4190 1133) A
discharge air temperature sensor is required for proper operation
Binary Input Switching Devices
Occupancy, condensate overflow, low-coil temperature, and fan status inputs accept switching
devices that may have normally open (NO) or normally closed (NC) dry contacts
Zone Temperature Sensors
The following table provides the sensor types and features supported by the UC400 Controller
Table 3. UC400 Controller Supported Sensors and Features
Features
Sensor
Type Setpoint Fan
Control System Occupancy LEDs Part
Number BAYSENS Global
Parts
Temperature
Sensor No
No No
No
No
X1351152801 BAYSENS077A SEN01448
No Yes X1351153001 BAYSENS073A SEN01450
Temperature
Sensors w/
Fan Control
Single • Off
• Auto
No
Yes
No
X1379084501
N/A
SEN01521
Single
• Off
• Auto
• Low
• High
Yes X1379084801 SEN01524
Single
• Off
• Auto
• Low
• Medium
• High
Yes X1379084201 SEN01518
Temperature
Sensor w/
LCD Display
(a)
Single
• Off
• Auto
• Low
• Medium
• High
No
Can be
configured
for
occupancy
No X1379088604 N/A N/A

12 BAS-SVX48H-EN
Table 3. UC400 Controller Supported Sensors and Features (continued)
Features
Sensor
Type Setpoint Fan
Control System Occupancy LEDs Part
Number BAYSENS Global
Parts
Wireless
Zone Sensor
w/Fan
Control
Single
• Off
• Auto
• Low
• Medium
• High
No Yes No
X1379082201
(Sensor Only)
N/A N/A
X1379082401
(Sensor Set)
(a) This sensor can be field configured to match the applicable unit controller options. Unit controller inputs for system status, fan, and service required are
not available on this sensor. If replacing a BAYSENS031A or a BAYSENS035A sensor, and status indicators are required, replace with non-display sensor
BAYSENS109A or BAYSENS110A.
Valve and Damper Actuators
The 2-position analog and 3-wire floating point modulating actuators cannot exceed 12 VA draw
at 24 Vac For 2-position valves, use actuators with ON/OFF and spring actions that returns the
valve to normally open (NO) or closed (NC), which are dependent on the desired default position
For modulating actuators, use actuators with or without a spring return, as required by the
application
Zone Humidity Sensor
For measurement of relative humidity (RH), the UC400 Controller requires a zone humidity
sensor with a 4–20 mA output, where 4 mA is 0% RH and 20 mA is 100% RH The controller
provides 24 Vdc to power the zone humidity sensor
NNoottee:: As an option, the UC400 Controller can recei e humidity from a Trane Air-fi™ Wireless
Sensor with Humidity.
CO2Sensor
The UC400 Controller assumes (by default) that the CO2sensor provides a 4-20 mA output when
measuring carbon dioxide (CO2) The controller provides 24 Vdc to power the CO2sensor
Expansion Modules
The UC400 Controller can power a maximum of two (2) DC expansion modules (either the Tracer
XM30 or Tracer XM32) without an additional power supply It can support a maximum of 32
additional XM30, XM32 or XM70 hardware terminations when properly applying power
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BAS-SVX48H-EN 13
Typical Applications and Terminations
The following tables provide information about supported applications and termination wiring
Table 4. UC400 Controller Typical Applications
Application Electric Heat
Auto Minimum
Damper Adjust Economizing
2-Pipe Cooling Only X X X
2-Pipe Changeover X X X
2-Pipe Heating Only X X
2-Pipe Steam Only X X
2-Pipe Face and Bypass Heat Only (Hot Water or Steam)(a) X X
4-Pipe X X
4-Pipe Changeover X X
4-Pipe Face and Bypass Changeover X X
4-Pipe Face and Bypass (Hot Water/Chilled Water) X X
Electric Heat Only(a) X X
4-Pipe Steam/chilled Water X X
DX Cooling X X X
DX Cooling with 2-Pipe Heating X X
DX cCooling with 2-Pipe Steam Heat X X X
DX Heat Pump Only X X
(a) Tracer UC400 supports single-stage, two-stage, and modulating electric heat.
Table 5. Factory Programmed Terminations
Inputs/Outputs/Communication Terminations Factory Programmed Assumed Terminations
Analog Inputs
AI1 Space Temperature Local/Return Air Temperature Sensor
AI2 Space Temperature Setpoint Local
AI3 Local Fan Switch
AI4 Discharge Air Temperature Sensor
AI5 Entering Water Temperature Sensor
Universal Inputs
UI1 Relative Humidity Sensor or CO2Sensor
UI2 Outside Air Temperature Sensor
Binary Inputs
BI1 Occupancy Sensor
BI2 Condensate Overflow Sensor
BI3 Low Limit Protection Sensor
Binary Outputs (Relay)
BO1 Fan High
BO2 Fan Medium/Exhaust Fan
BO3 Fan Low

14 BAS-SVX48H-EN
Table 5. Factory Programmed Terminations (continued)
Inputs/Outputs/Communication Terminations Factory Programmed Assumed Terminations
Binary Outputs (TRIAC)
BO4 Cooling, 2-Position Cooling, 3-Wire Floating Point Open Compressor 1
BO5
• Cooling, 3-Wire Floating Point Close
• Compressor 2
• Heating, 2-Position(a)
BO6
• Heating, 2-Position
• Heating, 3-Wire Floating Point Open
• Electric Heat Stage 1
• Face and Bypass Damper Open
BO7
• Heating, 3-Wire Floating Point Close
• Electric Heat Stage 2
• Face and Bypass Damper closed
• Reversing Valve
BO8 • Outside Air Damper, 2-Position
• Economizer, 3-Wire Floating Point Open
BO9 Economizer, 3-Wire Floating Point close
Analog Outputs/Binary Inputs
AO1/BI4 • Frost protection Status
• Cooling, Analog valve
AO2/BI5
• Fan Status
• Heating, Analog Valve
• Heating, SCR Modulating Electric Heat
Communication IMC ECM Engine Module
Pressure Inputs
PI1 Unused
PI2 Unused
(a) For face and bypass damper control applications.
Binary Inputs
The UC400 Controller has three (3) binary inputs and two (2) analog outputs/binary inputs
(labeled BI1 through BI5), that can be configured as either analog outputs or binary inputs Each
binary input associates an input signal of 0 Vac with open contacts and 24 Vac with closed
contacts If changes are required, use the Tracer TU service tool to unlock the points on and
configure each of the inputs as normally open (NO) or normally closed (NC)
BI1; Occupancy
Occupancy BI1 saves energy by spreading space temperature setpoints when the zone is
unoccupied Used as an occupancy input, BI1 has two (2) related functions:
• It changes the mode from occupied to occupied standby for controllers receiving a BAS-
communicated occupancy request
• It can be hard wired to a binary switch or time clock to determine the occupancy mode as
either occupied or unoccupied for stand-alone controllers
BI2; Condensate Overflow
Condensate Overflow BI2 prevents the condensate drain pan from overflowing and causing
water damage to the building If BI2 is wired to a condensate overflow switch, and the level of
TTyyppiiccaall AApppplliiccaattiioonnss aanndd TTeerrmmiinnaattiioonnss

BAS-SVX48H-EN 15
condensate reaches the trip point, the UC400 Controller detects the condition and generates a
Condensate Overflow diagnostic
BI3; ow Coil Temp Detection
Low Coil Temperature Detection BI3 protects the coil from freezing If BI3 is wired to a binary low
coil temperature detection device (freeze-protection switch) and a low coil temperature condition
exists, the UC400 Controller detects the condition and generates a Low Coil Temperature
Detection diagnostic
NNoottee:: This input is for Hydronic or Steam Coils only.
BI4; Frost Detection
Frost detection BI4 detects conditions that produce frost on the coil surface When these
conditions are present, the UC400 Controller detects the condition and generates a Frost
Detection Input alarm
NNoottee:: This input is for only DX.
BI5; Fan Status
Fan Status BI5 provides feedback to the UC400 Controller regarding the operating status of the
fan If BI5 is wired to a fan status switch, and the input indicates that the fan is not operating
when the controller has the fan controlled to ON, the controller generates a Low Airflow Supply
Fan Failure diagnostic
Analog Inputs
The UC400 Controller has seven (7) analog inputs
Ground Terminals
Use the terminal as the common ground for all space temperature sensor analog inputs
AI1; Space Temperature
Space Temperature AI1 functions as the local (hard wired) space temperature input The UC400
Controller receives the space temperature as a resistance signal from a 10 kΩ thermistor in a
standard Trane space temperature sensor that is wired to analog input AI1 A space temperature
value communicated by means of a BACnet link, can be used for controllers operating on a BAS
When both a hard wired and communicated space temperature value are present, and in service,
the controller uses the communicated value
If neither a hard wired nor a communicated space temperature value is present, the space
temperature local and active points go into a fault state and generates an alarm If neither the
hard wired or communicated space temperature are valid, the controller runs discharge air
control as backup The space temperature setpoint is used as the discharge air temperature
setpoint At the same time, the air valve modulates and reheat is used (if needed) to control the
discharge air temperature to the DAT setpoint
AI2; Space Temperature ocal Setpoint
Space Temperature Local Setpoint AI2 functions as the local (hard wired) space temperature
setpoint input for applications utilizing a Trane space temperature sensor with a temperature
setpoint thumbwheel or digital setpoint input A setpoint value communicated by means of a
BACnet link, can be used for controllers operating on a BAS If both hard wired and
communicated setpoint values are present, and in service, the UC400 Controller uses the
communicated value
In addition, the controller can be configured to use the local (hard wired) input value instead of
the communicated value using the Tracer TU service tool If neither a hard wired nor a
communicated setpoint value is present, the controller uses the space temperature setpoint
default analog value, which is configured using the Tracer TU service tool If a valid local setpoint
value is established, and then is no longer present, the controller generates a Space Temperature
Setpoint Local alarm
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16 BAS-SVX48H-EN
AI3; ocal Fan Mode Input
Local Fan Mode Input AI3 functions as the local (hard wired) fan mode switch input for
applications using the Trane space temperature sensor with a fan mode switch option The
various fan mode switch positions (OFF, LOW, MEDIUM, HIGH, AUTO) provide different
resistances that are interpreted by the UC400 Controller
NNoottee:: The local fan speed switch can be disabled by taking out of ser ice the multi-state point,
supply fan speed local and setting the alue for each to AUTO.
A communicated fan mode request by means of the BACnet communications link, can be used
for controllers operating on a BAS If both hard wired and communicated fan mode values are
present and in service, the UC400 Controller uses the communicated value However, the
controller can be configured to use the local (hard wired) input value instead of the
communicated BAS value The supply fan speed source (local or BAS) can be selected on the
Tracer TU Setup Parameters page If neither a hard wired nor a communicated fan mode value is
present, the controller recognizes the fan mode value as AUTO and operates according to the
default configuration If a valid hard wired or communicated fan mode value is established, and
then is no longer present, the controller generates a Supply Fan Speed Local alarm
AI4; Discharge Air Temperature Sensor
Discharge Air Temperature Sensor AI4 functions as the local discharge air temperature input
NNoottee:: A alid discharge air temperature alue is required for normal operation.
The UC400 Controller receives the temperature as a resistance signal from a 10 kΩ thermistor
wired to analog input AI4 The thermistor is typically located downstream from all unit heating
and cooling coils at the unit discharge area If a discharge air temperature value is invalid, or is
not present, the controller generates a Discharge Air Temp Failure alarm If there is a discharge
air temperature failure, the controller runs a simplified zone control algorithm and controls the
space to the unoccupied setpoints
AI5; Entering Water Temperature
Entering Water Temperature AI5 functions as the local (hard wired) entering water temperature
input An entering water temperature communicated by means of the BACnet communications
link, can be used for controllers operating on a BAS If both hard wired and communicated
entering water temperature values are present, and in service, the UC400 Controller uses the
communicated value If a valid hard wired or communicated entering water temperature value is
established, and then is no longer present, the UC400 Controller generates an Entering Water
Temperature Failure diagnostic
For units configured as 2-pipe or 4-pipe changeover units, the entering water temperature is used
to make heating/cooling operation decisions If neither a hard wired nor a communicated
entering water temperature value is present on changeover units, the UC400 Controller always
operates in heating mode
NNoottee:: For units not configured as changeo er units, the entering water temperature can be
manually configured and used for information and troubleshooting. It will not affect the
operation of the controller.
Universal Inputs
The UC400 Controller has two (2) universal inputs
UI1; Relative Humidity or CO2Sensor
If the UC400 Controller is configured for a local hard wired RH sensor, the factory programming
assumes it is wired to UI1 The pre-configured unit requires a 4-20 mA analog input
corresponding linearly to a 0%-100% relative humidity If the controller is configured for a local
hard wired CO2sensor, the factory programming also assumes it is wired to UI1 The pre-
configured unit requires a 4-20 mA analog input
TTyyppiiccaall AApppplliiccaattiioonnss aanndd TTeerrmmiinnaattiioonnss

BAS-SVX48H-EN 17
UI2; Outdoor Air Temperature
If UI2 is configured as the local (hard wired) outdoor air temperature input, the UC400 Controller
receives the temperature as a resistance signal from a 10 kΩ thermistor wired to UI2 An outdoor
air temperature value communicated by means of a BACnet link, can be used for controllers
operating on a BAS If both hard wired and communicated outdoor air temperature values are
present, and in service, the controller uses the communicated value If a valid hard wired or
communicated outdoor air temperature value is established, and then is no longer present, the
controller generates an Outdoor Air Temperature Failure alarm
The economizing (free cooling) function uses outdoor air is used as a source of cooling before
using hydronic or DX cooling The controller uses the outdoor air temperature value to
determine whether economizing is feasible Economizing is not possible without a valid outdoor
air temperature The outdoor air temperature value is used for the freeze avoidance function
This function is used for low coil temperature protection when the fan is OFF The controller
enters the freeze avoidance mode when the outdoor air temperature is below the freeze
avoidance setpoint (configured using the Tracer TU service tool)
Binary Outputs
The UC400 includes nine (9) binary outputs BO1, BO2, and BO3 are relay outputs and BO4
through BO9 are TRIAC outputs
IImmppoorrttaanntt:: 24 Vac must be pro ided to the TRIAC supply input.
The UC400 supports the following blower coil, fan coil, and unit ventilator applications:
• Supply fan with 1-, 2-, or 3–speed or variable speeds
• Face/bypass damper for some hydronic Unit Ventilator applications
• DX cooling single- or dual-stage
• Electric heat single stage, two stage, or modulating
• A 2-position or 3-wire floating point modulating outdoor/return air damper
Override Outputs
Analog and multi-state value request points are included in order to safely override outputs
without disrupting TGP2 program operation To override valves and dampers for commissioning
or testing purposes, access the following points on the Analog or Multi-state tabs of the Tracer
TU service tool :
•CCooooll VVaallvvee RReeqquueesstt:: analog value point for 2-position and modulating hydronic cooling and
changeover valve
•DDXX CCooooll RReeqquueesstt:: analog value point for 1- and 2-stage DX cooling and heat pump
•HHeeaatt VVaallvvee RReeqquueesstt:: analog value point for 2-position and modulating hydronic heating
valve
•EElleeccttrriicc HHeeaatt RReeqquueesstt:: analog value point for modulating, 1- and 2-stage electric heating
•EEccoonnoommiizzeerr RReeqquueesstt:: analog value point for 2-position and modulating outdoor air damper
•SSuuppppllyy FFaann SSppeeeedd RReeqquueesstt:: analog value point for variable speed (0-100%) fan applications,
including Trane ECM engine module
•SSuuppppllyy FFaann SSppeeeedd BBAASS:: multi-state value point for fixed 1-, 2-, and 3-speed fan
Wiring Requirements
The following table lists the required UC400 Controller inputs for minimum proper operation of
all applications The following wiring diagrams are separated to show first the UC400 and then
the UC400–B
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18 BAS-SVX48H-EN
Table 6. Inputs
Function Input source Related information
24 Vac Power Terminals: Ground, 24 Vac For more details on power wiring requirements, refer to
“Resources,” p. 67.
Space Temperature Local Terminals: AI1, Ground AI1; Space Temperature Local
Discharge Air Temperature Terminals: AI4 AI4; Discharge Air Temperature Sensor
Entering Water Temperature
(Required Only for Units with Auto-
changeover)
Terminal: AI5 or Communicated AI5; Entering Water Temperature
Outdoor Air Temperature Local
(Required Only for Economizing) Terminals: UI2 or Communicated UI2; Outdoor Air Temperature
CO2Sensor (Required Only for CO2-
based Demand Controlled
Ventilation)
CO2and an Economizer Damper are
Required for Demand Control
Ventilation Operation.
Demand Control Ventilation is
Disabled When:
• The Economizer Damper is not
Installed.
• No CO2Sensor or Value does Not
Exist
• The Mode of Operation is
Unoccupied, Pre-cool, Morning
Warm-up, or Anytime When the
Fan is OFF.
Terminals: UI1 or Communicated UI1; Relative Humidity or CO2Sensor
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BAS-SVX48H-EN 19
UC400 Wiring Diagrams
Figure 2. Common Input/Sensor Connections
VAC
24
XFRM VAC
24
VAC
24
BI 1 BI 2 BI 3
LINK IMC
+
24
VDC
BI4
AO1 BI
5
AO2 UI
1
UI
2
AI
3
AI
2
AI
1
AI
4
AI
5
P
1
P
2
IM
C
1
IM
C
1
4
3
2
VAC
24
XFRM VAC
24
VAC
24
BI
1
BI
2
BI
3
LINK IMC
+
24
VDC
BI4
AO1 BI
5
AO2 UI
1
UI
2
AI
3
AI
2
AI
1
AI
4
AI
5
P
1
P
2
CNCNO BO3 CNCNO BO2 CNCNO BO1 RELAYS
ADDRESS
TRIAC SUPPLY TRIACS
A
BO9BO8BO7BO6BO5BO4
A BB
TX
RX
LINK IMC
SERVI
C
E
SERVICE TOOL
CONNECT AC POWER TO THE TRAIC SUPPLY TO POWER THE TRIACS
BO1 BO2 BO3 BO4 BO5 BO6 BO7 BO8 BO9
1
2
3
4
5
6
7
8
9
IM
C
1
IM
C
1
3
4
5
6
7
1
2
3
4
5
6
7
8
9
8
9
Ground 24 Vac
Occupancy
(Open Occu)
Condensate
Overflow
(NC) Low Coil
Temp
Detection
(NC)
Comm In
Comm Out
Supply Fan Speed
Space Temp Setpoint
Space Temp
Ground
Pressure Inputs
Entering
Water Temp
Relative
Humidity Local
or Indoor CO2
Concentration
(Opt)
Supply Fan
Status (NC)
Frost
Detection
Input
Space
Temp
Sensor
Two-Tier
Terminal
Connections
Outdoor Air
Temp
Local
Disc harge
Air Temp
Zone Sensor Service
Tool Connection
Auxiliary 24 Vdc
Output
• BI4 Frost Detect Input used
to detect freeze conditions
that produce frost on the
coil surface.
• UI1 Relative Humidity Sensor
can be used with dehumidifying
unit instead of a BAS-
communicated valve or CO2
Sensor can be used for Demand
Controlled Ventilation instead
of a BAS-communicated value.
•AI5 Entering Water Temp
Sensor used for auto-
changeover units.
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20 BAS-SVX48H-EN
Figure 3. 2–Position Ventilation and Modulating Economizer
VAC
24
XFRM VAC
24
VAC
24
BI
1
BI
2
BI
3
LINK IMC
+
24
VDC
BI
4
AO1
BI
5
AO2 UI
1
UI
2
AI
3
AI
2
AI
1
AI
4
AI
5
P
1
P
2
CNCNO BO3 CNCNO BO2 CNCNO BO1 RELAYS
ADDRESS
TRIAC SUPPLY TRIACS
A
BO9BO8BO7BO6BO5BO4
A BB
TX
RX
LINK IMC
SERVI
C
E
SERVICE TOOL
CONNECT AC POWER TO THE TRAIC SUPPLY TO POWER THE TRIACS
BO1 BO2 BO3 BO4 BO5 BO6 BO7 BO8 BO9
1
2
3
4
5
6
7
8
9
IM
C
1
IM
C
1
3
4
5
6
7
1
2
3
4
5
6
7
8
9
8
9
TRIAC SUPPLY TRIACS
A
BO9BO8BO7BO6BO5BO4
A BB
CONNECTAC POWER TO THE TRAIC SUPPLY TO POWER THE TRIACS
TRIAC SUPPLY TRIACS
A
BO9BO8BO7BO6BO5BO4
A BB
CONNECTAC POWER TO THE TRAIC SUPPLY TO POWER THE TRIACS
open
closed
Single-Tier
Terminal
Connections
2-position Ventilation Terminal Connections
Modulating Economizer Damper Terminal Connections
Ground
Outside Air Damper
Outside Air Damper
Ground
To 24 Vac
Supply
To 24 Vac
Supply
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