Carrier UC Open XP Instructions and recipes

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Catalog No. 04-53390010-01 Printed in U.S.A. Form 39M-12SI Pg 1 10-12 Replaces: 39M-3SI
Installation and Start-Up Instructions
TABLE OF CONTENTS
Page
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . . 1
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Service Area Requirements . . . . . . . . . . . . . . . . . . . . . . 2
Electrical Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . 2
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-12
UC Open XP Control System . . . . . . . . . . . . . . . . . . . . 10
Control System Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . 10
To Wire the Controller to the Network . . . . . . . . . . . 11
COMPONENT INSTALLATION AND
FIELD WIRING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-22
Wiring Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Supply-Air Temperature Sensor . . . . . . . . . . . . . . . . . 12
Fan Status Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Fan Status Switch Adjustment. . . . . . . . . . . . . . . . . . . 14
Fan Status Switch Field Installation . . . . . . . . . . . . . 14
Return-Air Temperature Sensor . . . . . . . . . . . . . . . . . 15
Outdoor-Air Temperature Sensor . . . . . . . . . . . . . . . . . 15
Mixed-Air Temperature Sensor . . . . . . . . . . . . . . . . . . 15
Low-Temperature Thermostat . . . . . . . . . . . . . . . . . . . 15
Preheat Temperature Sensor . . . . . . . . . . . . . . . . . . 15
Filter Status Switch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Steam/Water Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Field-Supplied Two-Position Water Valves . . . . . . . 18
Mixing Box Damper Actuators . . . . . . . . . . . . . . . . . . . 18
Exhaust Damper Actuator . . . . . . . . . . . . . . . . . . . . . . . 19
Face and Bypass Damper Actuator . . . . . . . . . . . . . . 19
Variable-Frequency Drives . . . . . . . . . . . . . . . . . . . . . . 19
DX Cooling Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Electric Heat Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Electric Heat Sequencer . . . . . . . . . . . . . . . . . . . . . . . . . . 21
SCR Controller. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Vernier Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
TROUBLESHOOTING. . . . . . . . . . . . . . . . . . . . . . . . . 22,23
Communication LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
UC OPEN XP SPECIFICATIONS. . . . . . . . . . . . . . . . . . 23
UC OPEN XP IO SPECIFICATIONS . . . . . . . . . . . . . . . 24
SAFETY CONSIDERATIONS
Installation and start-up of air-handling equipment can be
hazardous due to system pressure, rotating parts, and electrical
components. Only trained and qualified service personnel
should install, start-up or service air-conditioning equipment.
When working on air-conditioning equipment, observe
precautions in the literature, tags and labels attached to the unit,
and other safety precautions that may apply.
Follow all safety codes, including ANSI (American National
Standards Institute) Z223.1 or latest version. Wear a hard hat,
safety glasses, and work gloves.
IMPORTANT: This equipment generates, uses, and
can radiate radio frequency energy and if not installed
and used in accordance with these instructions may
cause radio interference. The equipment has been tested
and complies with the limits of a Class A computing
device as defined by FCC (Federal Communications
Commission) regulations, Subpart J of Part 14, which
are designed to provide reasonable protections against
such interference when operated in a commercial
environment.
WARNING
Disconnect all power to the unit, then lock out and safety
tag all disconnects before performing maintenance or
service. Unit may automatically start if power is not
disconnected. Electrical shock and personal injury could
result.
WARNING
DO NOT USE TORCH to remove any component. System
contains oil and refrigerant under pressure.
To remove a component, wear protective gloves and gog-
gles and proceed as follows:
a. Shut off electrical power to unit.
b. Recover refrigerant to relieve all pressure from sys-
tem using both high-pressure and low pressure ports.
c. Traces of vapor should be displaced with nitrogen
and the work area should be well ventilated. Refrig-
erant in contact with an open flame produces toxic
gases.
d. Cut component connection tubing with tubing cutter
and remove component from unit. Use a pan to catch
any oil that may come out of the lines and as a gage
for how much oil to add to the system.
e. Carefully unsweat remaining tubing stubs when nec-
essary. Oil can ignite when exposed to torch flame.
Failure to follow these procedures may result in personal
injury or death.
CAUTION
DO NOT re-use compressor oil or any oil that has been
exposed to the atmosphere. Dispose of oil per local codes
and regulations. DO NOT leave refrigerant system open to
air any longer than the actual time required to service the
equipment. Seal circuits being serviced and charge with
dry nitrogen to prevent oil contamination when timely
repairs cannot be completed. Failure to follow these proce-
dures may result in damage to equipment.
FOR YOUR SAFETY
Do not store or use gasoline or other flammable vapors and
liquids in the vicinity of this or any other appliance.
UC Open XP/UC Open XP IO
for 39MN,MW Indoor and
Weathertight Outdoor Air Handlers

2
INTRODUCTION
General — Carrier’s UC Open XP central station air han-
dler controls provide heating, cooling, and ventilation control
for constant volume (CV) and variable air volume (VAV)
applications.
The control box provides centralized management of the air
handler operation. A control module is supplied in the control
box which can store hundreds of configuration settings and set
points. It also performs self diagnostic tests at unit start-up,
monitors the operation of the unit, and provides alarms.
The controls can operate either stand-alone or can be
interfaced with BACnet*. If a controller is installed as part of a
network, the controller is connected to the BACnet communi-
cation bus with a field-installed cable.
When ordered along with a 39M unit, the UC Open XP is
installed inside a control box in its own control plenum or ex-
ternally mounted on the supply fan section. See Fig. 1 and
Fig. 2. All factory-installed sensors will be wired to one of 2 lo-
cations based on the controls option selected in AHUBuilder®
program as outlined below:
NO PRODUCT INTEGRATED CONTROLS — No sen-
sors are installed nor wired in the AHU (air-handling unit).
FACTORY WIRED - NO CONTROLLER — All factory-
installed sensors are wired to a terminal strip normally located
in either a control plenum or the supply fan section.
FACTORY WIRED - UNPROGRAMMED CONTROL-
LER IN CONTROL PLENUM — All factory-installed sen-
sors are wired to a terminal strip inside the control plenum.
The UC Open XP controller is then wired to the terminal strip
and mounted inside the control plenum.
If shipping splits exist, wiring will be terminated at each
split with a molex type quick connect at each end of the wiring.
The control box includes the control module, circuit breaker,
transformers, and terminal blocks. An ON/OFF switch is pro-
vided to shut off the control box power.
The control box environmental limitations are as follows:
Shipping Temperature — –24 to 140 F
Shipping Humidity — 0 to 90%
Operating Temperature — 0 to 140 F
Operating Humidity — 0 to 90%
Service Area Requirements — Article 110-16 of the
NEC (National Electrical Code) describes electrical installation.
All UC Open XP control installations must comply with the
minimum clearances required for electrical installation as listed
in Table 110-16(a) of the code. Make sure to provide the neces-
sary clearance from the UC Open XP controls and unit to any
adjoining wall. Refer to the base unit installation instructions
for detailed dimensions for each unit section.
Electrical Requirements — The control system will
run off of the AHU system's power through 2 transformers to
adjust the incoming voltage to 24 vac ± 10%. The incoming
power supply may be 50 or 60 Hz and capable of providing a
minimum of 3 amps (but not greater than 20 amps) to the con-
trol board. Do not run Class I power wiring in the same con-
duit as Class II sensor wiring, control wiring of field-installed
devices, or the Class motor starter wiring.
Refer to Fig. 3 and 4 for control box components. Various
wiring details are shown in Fig. 5 and 6. Factory-supplied and
wired controller input and output points are listed in Tables 1
and 2 and corresponding terminal numbers in the control are
shown in Fig. 7 and 8.
The supply and return fan starter circuits are independent
from each other. Either circuit can be 24 vac, 120 vac, or
240 vac powered.
All factory-supplied and installed accessories are powered
by factory-installed transformers. Each transformer is UL (Un-
derwriters Laboratories) listed as a Class II device. An accesso-
ry transformer is required on the CO2sensor.
All electrical components are UL listed. The electronic
control module and control box assembly are approved under
UL HVAC (Heating, Ventilation and Air Conditioning)
Equipment Standard 873 for temperature indicating and
regulatory equipment. When ordered factory-supplied with the
air-handling equipment, the control is listed and labeled by
ETL to UL Standard 1995 for heating and cooling units, and
comply with NFPA (National Fire Protection Association)
Standard 90A.
IMPORTANT: To ease installation and servicing, all
field-installed sensor wiring should be located on the
service side of the unit. All factory wiring run between
sections, which are equipped with separation joints,
has factory-supplied connections. The wiring must be
disconnected if the unit is separated for service.
CAUTION
Power is present in the control box from the motor starter
circuit even when the dedicated power to the control box is
off.
Fig. 1 — Typical Control Box Installation on
39M Supply Fan Section
a34-4317
* Sponsored by ASHRAE (American Society of Heating, Refrigerat-
ing, and Air Conditioning Engineers).

3
MIXED AIR TEMP
(MAT) SENSOR
DAMPER ACTUATORS
(EA, RA, OA) ELECTRIC HEATER
CONTROL BOARD
AND SEQUENCER
CONTROLLER AND/OR
TERMINAL STRIP
MOUNTED IN OWN PLENUM
OR EXTERNAL TO UNIT
FILTER STATUS
SWITCH (FLTS)
SUPPLY AIR
TEMP (SAT)
SENSOR
LOW TEMP
THERMOSTAT
(LTT OR FREEZESTAT)
a33-9293
Fig. 2 — 39M Typical Sensor, Actuator, and Controller Installation Locations
Fig. 3 — Sensor Only Terminal Box
a39-4320

4
Fig. 4 — UC Open XP Control Box Components
a39-4319

5
FOR SCR OPTION DO NOT CONNECT TO 24 VAC
Fig. 5 — UC Open Wiring Schematic
LEGEND
CCV — Cooling Coil Valve EH — Electric Heat EXH — Exhaust Damper FLTS — Filter Differential Pressure Switch HCV — Heat Coil Valve HDT — Hot Deck Temperature LTT — Low Temperature Thermostat MAD — Mixed Air Damper Actuator MAT — Mixed Air Temperature OAD — Outdoor Air Damper PHEAT — Preheat Temperature PHV — Preheat Valve RAD — Return Air Damper SAT — Supply Air Temperature SF — Supply Fan SF/SFR — Supply Fan Relay (Start/Stop) SPT — Set Point TB — Te r m i n a l B l o ck VFD — Variable Frequency Drive

6
Fig. 6 — Controller Wiring Schematic
a39-4366

7
Table 1 — Sensor Only Wire Designations
CONNECTION
DEVICE WIRE NO. WIRE PART NO. “A” END WIRE LABEL “A” END TERM WIRE COLOR WIRE LENGTH (in.)
“B” END WIRE
LABEL “B” END TERM
T1 24Vac
Power
1 39MA51007701 CB1-2 J BROWN 18 J1-1 E
BROWN 18 J1-1 E
2 39MA51007702 TRANS1-HOT C BROWN 15 CB1-1 C
T1 GND 3 39MA51007703 TRANS1-GND H GREEN/YELLOW 6 TRANS1-COM J J1-2 (6126 Gnd) E GREEN/YELLOW 27
4 39MA51007704 J1-2 (8160 Gnd) E GREEN 5 J1-2 (Gnd) E
T2 24Vac
Power
5 39MA51007705 TRANS2-HOT C BROWN 6 CB2-1 C
6 39MA51007706
CB2-2 C BROWN 24 TB4-3 J
TB6-3 J BROWN 8
BROWN 8 TB8-3 J
TB7-3 J BROWN 8
BROWN 6 TB1-3 J
TB5-3 J BROWN 8
BROWN 4 TB9-3 J
TB10-3 J BROWN 6
BROWN 21 LTT-1 D
7 39MA51007707 LTT-1 C GREY 7 J5-1 (ExBO-1) E
8 39MA51007708 J5-1 (ExBO-1) E GREY 2 J5-3 (ExBO-2) E
9 39MA51007709 J5-3 (ExBO-2) E GREY 6 J5-11 (ExBO-6) E
T2 GND
10 39MA51007710 TRANS2-GND H GREEN/YELLOW 6 TRANS2-COM J
TB5-4 D GREEN/YELLOW 6
11 39MA51007711
TB2-3 D GREEN/YELLOW 12 TB4-4 J
TB6-4 J GREEN/YELLOW 8
GREEN/YELLOW 6 TB8-4 J
TB7-4 J GREEN/YELLOW 6
GREEN/YELLOW 6 TB1-4 J
TB5-4 J GREEN/YELLOW 6
GREEN/YELLOW 3 TB9-4 J
TB10-4 J GREEN/YELLOW 6
GREEN/YELLOW 16 CR3-2 C
LTT
12 39MA51007712 LTT-2 CBROWN 12 CR3-1 J
CR2-3 BROWN 4
13 39MA51007713
CR2-1 C BLUE 6 CR3-3 J
CR3-4 J BLUE 4
BLUE 24 TB2-4 C
14 39MA51007714 TB3-2 C YELLOW 18 CR2-5 C
15 39MA51007715 CR2-6 C YELLOW 17 TB3-3 D
16 39MA51007716 CR2-2 C RED 34 J4-9 (UI-05) E
17 39MA51007717 CR2-4 C BLACK 34 J4-11 (Gnd) E
MAD 18 39MA51007718 TB4-1 C RED 26 J9-1 (AO-1) E
19 39MA51007719 TB4-4 D GREEN/YELLOW 26 J9-2 (Gnd) E
RAD 20 39MA51007720 TB9-1 J RED 24 TB4-1 D
EXD 21 39MA51007721 TB10-1 C RED 6 TB9-1 D
HCV 22 39MA51007722 TB5-1 C RED 28 J9-3 (AO-2) E
2 Pos HCV 23 39MA51007723 TB5-2 C WHITE 32 J5-2 (ExBO-1) E
CCV 24 39MA51007724 TB1-1 C RED 25 J9-5 (AO-3) E
2 Pos CCV 25 39MA51007725 TB1-2 C WHITE 29 J5-4 (ExBO-2) E
PHV/F&B 26 39MA51007726 TB6-1 C RED 24 J9-11 (AO-6) E
2 Pos PHV 27 39MA51007727 TB6-2 C WHITE 24 J5-12 (ExBO-6) E
FLTS 28 39MA51007728 TB2-1 C RED 24 J4-3 (UI-01) E
29 39MA51007729 TB2-2 C BLACK 24 J4-5 (Gnd) E
FLTS2 30 39MA51007730 TB2-11 C RED 24 J2-15 (ExIN-16) E
PREHEAT 31 39MA51007731 TB2-5 C RED 24 J2-1 (ExIN-09) E
HOT DECK 32 39MA51007732 TB2-6 C RED 24 J2-3 (ExIN-10) E
MAT 33 39MA51007733 TB2-7 C RED 21 J4-6 (UI-03) E
Gnd
34 39MA51007734 TB2-8 C BLACK 24 J2-4 (Gnd) E
35 39MA51007735 TB2-9 J BLACK 26 J4-8 (Gnd) E
BLACK 3 TB2-12 C
SAT 36 39MA51007736 TB2-10 C RED 21 J4-4 (UI-02) E
HUMIDIFIER 37 39MA51007737 TB6-2 C ORANGE 30 J16-6 (BO-2) E
SF VFD 38 39MA51007738 TB8-1 C RED 24 J9-7 (AO-4) E
SF s/s 39 39MA51007739 TB3-3 C YELLOW 28 J16-3 (BO-1no) E
40 39MA51007740 TB3-4 C YELLOW 28 J16-2 (BO-1com) E
RF VFD 41 39MA51007741 TB8-2 C RED 24 J9-9 (AO-5) E
RF s/s 42 39MA51007742 TB3-5 C PINK 26 J16-9 (BO-3no) E
43 39MA51007743 TB3-7 C PINK 24 J16-8 (BO-3com) E
Comm
Jumpers
44 39MA51007744 OPN-UCXPIO Xnet (-) E BLACK 5 OPN-UCXP Xnet (-) E
45 39MA51007745 OPN-UCXPIO Xnet (+) E RED 5 OPN-UCXP Xnet (+) E
46 39MA51007746 OPN-UCXPIO Xnet GND E WHITE 5 OPN-UCXP Xnet GND E

8
Table 2 — UC Open XP Wire Designations
DEVICE / CHANNEL # / CABLE # WIRE COLOR TERMINAL SIGNAL
FILTER STATUS SWITCH (CHANNEL # UI-1)
CABLE #3
WHITE TB2-1 DRY CONTACT DI
BLACK TB2-2 SIGNAL GROUND
SUPPLY AIR TEMPERATURE (CHANNEL # UI-2)
CABLE #1
WHITE TB2-10 10K THERMISTOR AI
BLACK TB2-12 SIGNAL GROUND
MIXED AIR TEMPERATURE (CHANNEL # UI-3)
CABLE #4
WHITE TB2-7 10K THERMISTOR AI
BLACK TB2-8 SIGNAL GROUND
OAT (CHANNEL #UI-4)
(FIELD SUPPLIED / INSTALLED)
FIELD INST U1-4 J4-7 10K THERMISTOR AI
FIELD INST GND J4-8 SIGNAL GROUND
LOW TEMPERATURE THERMOSTAT (FREEZSTAT)
(CHANNEL #UI-5) CABLE #2
WHITE TB2-4 DRY CONTACT D1
BLACK TB2-3 SIGNAL GROUND
SUPPLY FAN STATUS (CHANNEL #UI-6)
CABLE #2
FIELD INST U1-6 J4-10 DRY CONTACT D1
FIELD INST UIGND J4-11 SIGNAL GROUND
RETURN AIR TEMPERATURE (CHANNEL #UI-7) FIELD INST UI-6 J4-10 10K THERMISTOR AI
FIELD INST GND J4-11 SIGNAL GROUND
SPACE RH (CHANNEL #UI-8)
FIELD INST UI-8 J4-13 4-20 MA (+)
FIELD INST PWR OUT J4-1 +24 VDC POWER
FIELD INST GND J4-14 SIGNAL GROUND
SPACE INDOOR AIR QUALITY (CHANNEL #UI-11)
FIELD INST UI-10 J4-16 4-20 MA (+)
FIELD INST PWR OUT J4-1 +24 VDC POWER
FIELD INST GND J4-17 SIGNAL GROUND
OUTDOOR AIR QUALITY (CHANNEL #UI-11)
FIELD INST UI-11 J4-18 4-20 MA (+)
FIELD INST PWR OUT J4-1 +24 VDC POWER
FIELD INST GND J4-20 SIGNAL GROUND
BP (CHANNEL #UI-12)
(FIELD SUPPLIED / INSTALLED)
FIELD INST UI-12 J4-19 4-20 MA (+)
FIELD INST PWR OUT J4-1 +24 VDC POWER
FIELD INST GND J4-20 SIGNAL GROUND
RETURN EXHAUST FAN STATUS (CHANNEL # EXIN-1)
CABLE #19
FIELD INST EXIN-1 J3-1 DRY CONTACT D1
FIELD INST EXGND J3-2 SIGNAL GROUND
HIGH SUPPLY DUCT RH
(CHANNEL # EXIN-2)
FIELD INST EXIN-2 J3-3 DRY CONTACT D1
FIELD INST EXGND J3-4 SIGNAL GROUND
FIRE/SMOKE SHUTDOWN CONTACT
(CHANNEL # EXIN-3)
FIELD INST EXIN-3 J3-5 DRY CONTACT D1
FIELD INST EXGND J3-6 SIGNAL GROUND
SMOKE MODE EVACUATION INPUT
(CHANNEL # EXIN-4)
FIELD INST EXIN-4 J3-7 DRY CONTACT D1
FIELD INST EXGND J3-8 SIGNAL GROUND
SMOKE MODE PRESSURIZATION INPUT
(CHANNEL # EXIN-5)
FIELD INST EXIN-5 J3-9 DRY CONTACT D1
FIELD INST EXGND J3-10 SIGNAL GROUND
SMOKE MODE PURGE INPUT
(CHANNEL # EXIN-6)
FIELD INST EXIN-6 J3-11 DRY CONTACT D1
FIELD INST EXGND J3-12 SIGNAL GROUND
ENTHALPY SWITCH
(CHANNEL # EXIN-7)
FIELD INST EXIN-7 J3-13 DRY CONTACT D1
FIELD INST EXGND J3-14 SIGNAL GROUND
PRE-HEAT (CHANNEL # EXUI-9)
CABLE #7
WHITE TB2-5 10K THERMISTOR A1
BLACK TB2-8 SIGNAL GROUND
HOT DECK TEMPERATURE (CHANNEL # EXUI-10)
CABLE #18
WHITE TB2-6 10K THERMISTOR A1
BLACK TB2-8 SIGNAL GROUND
FILTER STATUS SWITCH 2 (CHANNEL # EXUI-16
CABLE #17
WHITE TB2-11 DRY CONTACT D1
BLACK TB2-12 SIGNAL GROUND
SUPPLY FAN MOTOR START/STOP
(CHANNEL # DO-1)
CABLE #10
RED TB3-2 STATER (HOT)
WHITE TB3-3 HAND
GREEN TB3-4 STARTER (AUTO)
HUMIDIFIER ENABLE
(CHANNEL # DO-2)
CABLE #16
RED N/C
WHITE TB6-2 24VAC SIGNAL
BLACK TB6-4 GROUND
GREEN N/C
RETURN FAN/EXHAUST FAN MOTOR START/STOP
(CHANNEL # DO-3) CABLE #11
WHITE TB3-5 STARTER (HOT)
GREEN TB3-7 STARTER (AUTO)
MIXED AIR DAMPER / OUTDOOR AIR DAMPER
(CHANNEL # AO-1)
CABLE #5
RED TB4-1 0-10 VDC AO
WHITE TB4-3 +24 VAC
BLACK TB4-4 POWER GROUND
GREEN N/C
RETURN AIR DAMPER
(SMOKE CONTROL)
(CHANNEL # ?)
CABLE #22
RED TB9-1 0-10 VDC AO
WHITE TB9-3 +24 VAC
BLACK TB9-4 GROUND
GREEN N/C
EXHAUST AIR DAMPER
(CHANNEL # ?)
CABLE #6
RED TB10-1 0-10 VDC AO
WHITE TB10-3 +24 VAC
BLACK TB10-4 GROUND
GREEN N/C
HEATING COIL VALVE
(CHANNEL # AO-2)
CABLE #9
RED TB5-1 0-10 VDC AO
WHITE TB5-3 +24 VAC
BLACK TB5-4 GROUND
GREEN N/C
COOLING COIL VALVE
(CHANNEL # AO-3)
CABLE #8
RED TB1-1 0-10 VDC AO
WHITE TB1-3 +24 VAC
BLACK TB1-4 GROUND
GREEN N/C
SUPPLY FAN VARIABLE FREQUENCY DRIVE SPEED
CHANNEL # AO-4) CABLE # 10
RED TB8-1 2-10 VDC AO
BLACK TB8-4 GROUND
RETURN FAN/EXHAUST FAN VARIABLE FREQUENCY SPEED
(CHANNEL # AO-5) CABLE #11
RED TB8-2 2-10 VDC AO
BLACK TB8-4 GROUND
ELECTRIC HEAT
(CHANNEL # AO-2)
CABLE #12
RED TB5-1 0-10 VDC AO
WHITE TB5-3 +24 VAC
BLACK TB5-4 GROUND
GREEN N/C

9
Table 2 — UC Open XP Wire Designations (cont)
DEVICE / CHANNEL # / CABLE # WIRE COLOR TERMINAL SIGNAL
PRE-HEAT VALVE
(CHANNEL # AO-6)
CABLE #20
RED TB6-1 0-10 VDC AO
WHITE TB6-3 +24 VAC
BLACK TB6-4 GROUND
GREEN N/C
FACE AND BYPASS DAMPER
(CHANNEL # AO-6)
CABLE #20
RED TB6-1 0-10 VDC AO
WHITE TB6-3 +24 VAC
BLACK TB6-4 GROUND
GREEN N/C
DIRECT EXPANSION STAGES 1,2,3
(CHANNEL # DO-4, -5, -6
(FIELD SUPPLIED / INSTALLED)
FIELD INST. BO-4 J16-12 DX STAGE 1 (24 VAC)
FIELD INST. BO-5 J16-15 DX STAGE 2 (24 VAC)
FIELD INST. BO-6 J16-18 DX STAGE 3 (24 VAC)
FIELD INST. TB1-4 GROUND
DIRECT EXPANSION STAGES 4,5,6
(CHANNEL # EXDO-3, -4, -5
(FIELD SUPPLIED / INSTALLED)
FIELD INST. EXBO-3 J5-6 DX STAGE 4 (24 VAC)
FIELD INST. EXBO-4 J5-8 DX STAGE 5 (24 VAC)
FIELD INST. EXBO-5 J5-10 DX STAGE 6 (24 VAC)
FIELD INST. TB1-4 GROUND
BACnet ®
24VAC
Gnd
24VAC, 50-60 Hz
20VA, 0.83A
Use Copper
Conductors Only UC Open XP
(OPN-UCXP)
Rnet Local
Access
Xnet
Remote
Expansion
Gnd
Xnet -
Xnet +
Gnd
Rnet +
Rnet -
+ 12V
Gnd
Rnet +
Rnet -
+ 12V
Sense
BACnet Port
Open Energy
Management Equipement
Pulse Count Ability
Aux Pwr Out
a39-4347
Fig. 7 — UC Open XP Input and Output Terminals

10
INSTALLATION
Leave protective coverings on the unit until it is installed
indoors and protected from the elements, construction debris,
and dirt.
The control box is shipped mounted in either the control
plenum or external to the supply fan section. Visually inspect
all components and wiring for any damage.
Control cable connectors are provided at each base rail split
for easy disassembly and/or reassembly, allowing the unit to be
shipped and/or installed in pieces.
UC Open XP Control System — The UC Open XP
control system consists of a control board, sensors and con-
trolled devices.
The UC Open XP is able to be loaded with nearly any type
of controls software to control the unit. The user communi-
cates with the UC Open XP controller with a service tool (lap-
top), using one of many types of software including i-Vu®Ap-
plication Builder. Communications between the controller and
other devices on the network are accomplished using a 3-wire
bus that runs between controls.
The control board is powered from a 24 vac transformer
connected to the power input connector.
The control board monitors and controls components such
as the supply fan, cooling and heating coil valves, mixed-air
dampers, electric heat, etc.
Control System Wiring — The UC Open XP wiring is
all internal to the 39M air handler. Since air-handling systems
are normally made up of multiple component sections, Carrier
has designed the control system wiring using quick connect
snap plugs on wires that run between sections.
There may be multiple devices mounted within the various
sections, which all must connect back to the UC Open XP con-
troller. Figure 9 illustrates the connectivity between air-han-
dling sections.
On the UC Open XP, there is a power plug, a plug to con-
nect the module to optional I/O modules within the control
panel, and a plug to daisy-chain the module to additional mod-
ules within the network or other building management system.
NOTE: Conductors and drain wire must be 22 or 24 AWG
(American Wire Gage) minimum, low-capacitance, twisted,
stranded shielded copper wire. Individual conductors must be
insulated with PVC, PVC/nylon, vinyl, Teflon*, or polyethyl-
ene. An aluminum/polyester 100% foil shield and an outer
jacket of PVC, PVC/nylon, chrome vinyl, or Teflon with a
minimum operating temperature range of –20 C to 60 C is
required. See Table 3 for cables that meet the requirements.
Table 3 — Cable Requirements
AI/UI
DI/BI
DO/BO
Fig. 8 — UC Open XP IO Input and Output Terminals
a39-4323
MANUFACTURER CABLE NO.
Alpha 2413 or 5463
American A22503
Belden 8772
Columbia 02525
* Registered trademark of DuPont.

11
When connecting the UC Open XP communication bus to a
system element, a color code system for the entire network rec-
ommended to simplify installation and checkout. The follow-
ing color code is recommended in Table 4.
Table 4 — UC Open XP Communications Bus to
System Element Color Code System
If a cable with a different color scheme is selected, a similar
color code should be adopted for the entire network. At each
system element, the shields of its communication bus cables
must be tied together. If the communication bus is entirely
within one building, the resulting continuous shield must be
connected to ground at only one point. If the communication
bus cable exits from one building and enters another, the
shields must be connected to ground at the lightning suppressor
in each building where the cable enters or exits the building
(one point only).
To Wire the Controller to the Network
NOTE: The UC Open XP communicates using BACnet on an
MS/TP network segment communications at 9600 bps, 19.2
kbps, 38.4 kbps, or 76.8 kbps. Wire the controllers on an MS/
TP network segment in a daisy-chain configuration.
NOTE: Install a BT485 on the first and last controller on a net-
work segment to add bias and prevent signal distortions due to
echoing. See Fig. 10.
1. Pull the screw terminal connector from the controller’s
power terminals labeled Gnd or 24 vac or Hot.
2. Check the communications wiring for shorts and
grounds.
3. Connect the communications wiring to the BACnet port’s
screw terminals labeled Net+, Net-, and Shield.
NOTE: Use the same polarity throughout the network
segment.
4. Verify that the MSTP jumper is set to MSTP. See
Fig. 11.
5. Set DIP switches 1 and 2 to the appropriate baud rate. See
the MSTP baud diagram on the UC Open XP. The default
baud rate is 76.8 kbps.
NOTE: Use the same baud rate for all controllers on the
network segment.
6. Set DIP switches 3 and 4 for MSTP. See Fig. 11.
SIGNAL
TYPE
CCN BUS
CONDUCTOR
INSULATION
COLOR
+12V
Rnet-
Rnet+
Gnd
RED
BLACK
WHITE
GREEN
Fig. 9 — Section to Section Wiring Connectors
A39-4357
Fig.10 — UC Open XP Communication Wiring
NOTE: See the MS/TP Networking and Wiring Installation Guide for more details.
a48-8581

12
7. Verify the jumper is set on the right 2 pins. See Fig. 12.
8. Verify that the Communication Selection jumper is set to
EIA-485. See Fig. 13.
9. Insert the power screw terminal connector into the UC
Open XP’s power terminals.
10. Verify communication with the network by viewing a
module status report.
COMPONENT INSTALLATION
AND FIELD WIRING
Wiring Requirements — All field wiring must comply
with NEC and all local requirements. The recommended
wiring is shown in Table 5.
Table 5 — Wiring Requirements
LEGEND
Refer to Table 6 for recommended brands and part numbers.
On units with factory-installed controls, each section (with
factory-installed sensors or actuators) is wired back to the
control plenum using UL listed, plenum type cable. All facto-
ry-supplied sensor wiring is terminated at the control box. Con-
nectors are provided at each base rail split for easy
disassembly.
NOTE: For application data regarding Space Temperature
Sensors, Air Quality (CO2) sensors and enthalpy and humidity
sensors please see the 39M Controls Application Data. For
installation and wiring instructions for these sensors please see
the Carrier Sensor Installation Guide.
Supply-Air Temperature Sensor (Fig. 14) — The
SAT sensor is factory installed and wired when either of the
"Factory Wired" control options is selected in the AHUBuild-
er®program. The sensor is normally located in the discharge
of the supply fan unless heating or cooling coils are located
downstream of the fan (blow-thru fans only). In a blow-thru
situation, the sensor is located on the discharge end of the last
blow-thru coil. The sensor consists of a thermistor encased
within a stainless steel probe and is mounted to a junction box.
The sensor's thermistor has a range of –245 to 185 F with a
nominal resistance of 10,000 ohms at 77 F. See Table 7.
SET TO 76.8K BAUD
BACnet MS/TP
UNUSED
O
N
1 2 34 5 6 7 8
Fig. 11 — MSTP Jumper
a39-4354
485 2-WIRE
Fig. 12 — 485 2-Wire Jumper
A39-4355
EIA-485
Fig. 13 — Communication Selection Jumper
A39-4356
INPUT MAXIMUM
LENGTH
MINIMUM
GAGE SHIELDING
0-5 Vdc
0-10 Vdc
500 feet
(152 meters)
22 AWG 100 feet Unshielded
100-500 feet Shielded
0-20 mA
1000 feet
(305 meters)
22 AWG 100 feet Unshielded
100-1000 feet Shielded
Thermistor
Dry Contact
Pulse Counter
TLO
500 feet
(152 meters)
22 AWG 100 feet Unshielded
100-500 feet Shielded
RTD 100 feet
(30 meters)
22 AWG Shielded
SPT Sensors 500 feet
(152 meters)
18 AWG Unshielded
AWG — American Wire Gage
RTD — Resistance Temperature Device
SPT — Setpoint
TLO — Timed Local Override
Fig. 14 — Supply-Air/Return-Air
Temperature Sensor (33ZCSENSAT)
.08 in.
(.2 cm)
FOAM GASKET
.4 in. O.D.
(1.02 cm O.D.)
.39 in.
(.99 cm)
5.5 in. ± .5
(14 cm ± 1.27 cm)
114 in. (2.9 m)
PLENUM-RATED CABLE
.25 in. ± .01 dia.
(.6 cm ± .003 dia.)
.175 in. dia. x .6 in.
(.45 cm dia. x 1.52 cm)
3.9 in.
(9.9 cm)
3 in.
(7.6 cm)
PROBE
a33-9293

13
Table 6 — Recommended Sensor and Device Wiring
LEGEND
AWG — American Wire Gage
*Wire rated at 200-v.
†For control wiring internal to a variable frequency drive, motor
starter, electric heater, or condensing unit control box, which has a
nameplate operating voltage greater than 300 VAC.
Table 7 — Temperature to Resistance Conversion
— 10K MAT, SAT and Preheat Thermistors
Fan Status Switch — The fan status switch monitors
any change in AC current that is indicative of a motor failure,
belt loss or slippage or mechanical failure of the fan. The fan
status switch is factory-supplied with each supply, return or ex-
haust fan when either of the "Factory Wired" control options
are selected. The switch is factory-installed and wired when a
VFD (variable frequency drive), starter or disconnect is factory
installed and sufficient room exists. Otherwise, the switch is
factory-supplied for field installation. See Fig. 15-18 for instal-
lation locations.
WIRE TYPE BELDEN PART NO. CAROL PART NO. ALPHA PART NO.
300-v, Non-Plenum, 60 C Minimum (CM)
2-Conductor, 18 AWG Cable 9740 C6101 (or C5460*) 1897C
4-Conductor, 18 AWG Cable 8489 C2404 (or C5084*) 1898/4C
3-Conductor, 20 AWG Shielded Cable 8772 C2528 2413C/5463
150-v, Plenum Rated (CMP/CL2P)
2-Conductor, 18 AWG Cable 82740 C8276 —
4-Conductor, 18 AWG Cable 82489 C8524 —
3-Conductor, 20 AWG Shielded Cable 83553 C8173 58133
600-v, High-Voltage Rated, 90 C†
2-Conductor, 18 AWG Cable 9486 — 5606B1801
4-Conductor, 16 AWG Cable — — 7616/4
3-Conductor, 18 AWG Shielded Cable — — 5646B1801
TEMPERATURE RESISTANCE (ohms)
°F °C 10K Thermistor
–40 –40.0 336,000.0
–31 –35.0 242,700.0
–22 –30.0 177,000.0
–13 –25.0 130,402.0
–4 –20.0 97,060.0
5–15.0 72,940.0
14 –10.0 55,319.0
23 –5.0 42,324.0
32 0.0 32,654.0
41 5.0 25,396.0
50 10.0 19,903.0
59 15.0 15,714.0
68 20.0 12,493.0
77 25.0 10,000.0
86 30.0 8,056.0
95 35.0 6,530.0
104 40.0 5,327.0
113 45.0 4,370.0
122 50.0 3,606.0
131 55.0 2,986.0
140 60.0 2,488.0
149 65.0 2,083.0
158 70.0 1,752.0
167 75.0 1,480.0
176 80.0 1,255.0
185 167.2 1,070.0
194 90.0 915.0
203 95.0 787.0
212 100.0 680.0
221 105.0 592.0
230 110.0 517.0
246 119.0 401.0
239 115.0 450.0
Fig. 15 — Fan Status Switch Installed in
Motor Starter
a39-4370

14
The fan status switch includes two status LED (light-emit-
ting diode) indicators that will indicate one of three states;
tripped on, current present but below trip point, and current off
or below the low end of the adjustable trip point range.
Fan Status Switch Adjustment — The fan status is
adjustable with an operating range of 0 to 150 Amps and is fac-
tory set to the 100 Amp trip point position. To adjust the trip
point:
1. With current flowing through the aperature of the current
switch, verify the Blue LED is on.
2. If the Blue LED is on, slowly adjust the potentiometer
(labeled as "TRP ADJ" in Fig. 17) clockwise until the
RED LED just turns on and stop immediately. The trip
point is now set at the normal operating load current.
.
Fan Status Switch Field Installation — If the
AHU is ordered with no VFD, starter or disconnect and the fan
status switch is supplied, then the fan status switch will ship in
the fan section for field installation. Follow the following steps
for field installation:
1. The fan status switch may be mounted in any position us-
ing the provided Tek Screws and holes in the base. Leave
a minimum distance of 1 inch between the current switch
and any other magnetic devices such as contactors and
transformers.
2. Loop (1 turn) "Black" wire from the conduit assembly
running into the starter/disconnect/VFD/bypass from the
motor through the sensor as shown in Fig. 18.
3. Connect the "Black" wire to the appropriate connector
within the starter/disconnect/VFD/bypass.
4. Connect the control wiring to the control connection ter-
minals near the top of the fan status switch as shown in
Fig. 18.
Fig. 16 — Fan Status Switch Installed in VFD
a39-4371
CAUTION
The fan status switches should be used on insulated con-
ductors only.
2.001
2X 0.188
0.942
OUTPUT:1.0
36.0Vac/Vdc
TRIP
OFF ON
TRIP
ADJ
ADJ.RANGE: 0.32 -150A
TRIP ON-ABOVE TRIP POINT
TERMINALS ACCEPT 16-22AWG COPPER WIRE ONLY
ACI A/MCS-A
AUTOMATION COMPONENTS
MIDDELTON , WI
Fig. 17 — Fan Status Switch
a39-4373

15
Return-Air Temperature Sensor — The return-air
temperature sensor (RAT) is ordered separately and installed in
the return-air duct (Fig. 14). Mount the sensor in the middle of
the return-air duct upstream from the return-air damper. The
sensor’s probe tip should be centered within the duct.
Outdoor-Air Temperature Sensor (OAT) (P/N
33ZCSENOAT) — The OAT sensor is ordered separately
for field installation and consists of a thermistor encased within
a probe. See Fig. 19.
The OAT Sensor has an operating range of –40 F to 245 F
with a nominal resistance of 10,000 ohms at 77 F and an accu-
racy of ± 36 F.
Mixed-Air Temperature Sensor — The mixed-air
temperature sensor measures the temperature of the air leaving
the mixing box. The MAT sensor is factory-supplied and in-
stalled when either of the "Factory Wired" control options is
selected in the AHUBuilder®program and a mixing box or fil-
ter mixing box is present. The sensor is located inside the last
mixing box in the airflow, and the terminal box is mounted on
the hand side of the unit.
This sensor uses multiple thermistor elements and provides
both mechanical and electrical averaging to achieve an average
temperature measurement over the entire element length.
Polarity is not a consideration. See Fig. 20 for an installation.
Low-Temperature Thermostat (LTT) (Fig. 21) —
The low-temperature thermostat (often referred to as a freeze-
stat) is factory-supplied and installed when there is a factory-
supplied and installed steam or water heating and/or cooling
coil and either of the "Factory Wired" control options is
selected in the AHUBuilder®program. The thermostat is used
to protect the equipment coils from freezing temperatures in
the event of a malfunction, by detecting the presence of a
potentially damaging condition. The UC Open XP control will
stop the fan if damaging conditions are detected. If field
installed, the LTT should be done so on the entering air side of
the first cooling coil in the equipment. (For heating only units,
it is installed on the leaving air side of the first heating coil.) A
single LTT is used for coil face areas up to 45 sq ft. For larger
coils, one LTT is used for each 45 sq ft of coil face area. If
multiple coils are used, such as a split coil, one LTT is used on
each coil even if the total coil face area is 45 square feet or less.
The UC Open XP control accommodates multiple LTTs.
The factory-supplied LTT has a range of 35 to 60 F and is
factory set at 35 F. The temperature setting is field adjustable.
To adjust the temperature set point, turn the adjustment screw
(located on the top of the case) until the position indicator is at
the desired temperature. (A clockwise rotation increases the set
point.)
The LTT operates two low voltage relays. The normally
closed contacts of one relay is wired in series with the motor
starter circuit. If a 1-ft section of the capillary tube senses cold
air at or below the thermostat setting, the fan shuts down. A
manual reset is provided in the control box to restart the fan
after the abnormal condition is corrected. The temperature
must exceed the set point by 5 F or more for the reset button to
restore the circuit to normal operation.
For all heating coils, the LTT sensor senses the temperature
of the air leaving the coil (downstream). For all cooling coils,
the LTT sensor sensing the temperature of the air entering the
coil (upstream).
The sensor is mounted to the coil baffle panel, near the
bottom. The capillary sensing tube is routed through the upper
bushing in the coil baffle panel. It is run vertically up and down
across the coil face and extends evenly across the coil face
from side to side. It will form a “W” pattern as shown in
Fig. 22 and 23.
The LTT control assembly and reset switch is installed on the
hand side of the section.
Preheat Temperature Sensor (PHEAT) — The
preheat temperature sensor measures the temperature of the air
leaving the preheat coil. The sensor is factory-supplied and
installed when there is an extended length electric heating coil
in its own section before a cooling coil and either of the "Fac-
tory Wired" control options is selected in the AHUBuilder®
program. The PHEAT sensor is normally on the downstream
side of the heating coil in the heating coil section.
The sensor consists of multiple thermistors evenly spaced and
encased within a flexible copper tube, which provides average
temperature sensing. The sensor tubing is installed on the
downstream side of the preheat coil and is serpentined so it can
sense average temperature. The preheat sensor has a range of
–40 to 185 F with a nominal resistance of 10,000 ohms at 77 F.
CONTROL WIRING
Fig. 18 — Fan Status Switch Installation
a39-4372
2.81 in.
(7.14 cm)
4.56 in.
(11.58 cm)
4.92 in.
(12.5 cm)
Fig. 19 — Outdoor-Air Temperature (OAT) Sensor
a33-9296
CAUTION
DO NOT set the low-temperature thermostat below 35 F.
Coil damage may result.

16
Filter Status Switch (P/N 33AMSENFLT000) —
The filter status differential pressure switch (FLTS) is a snap
action SPDT type switch. When a dirty filter element causes
the pressure drop across the filter media to exceed the switch
setting, the switch closes and sends an alarm signal to the con-
trol box. The switch has a set point range from 0.05 to 2.0 in.
wg. Refer to the filter manufacturer’s information for the maxi-
mum dirty filter pressure drop, or use Table 8 determine the
appropriate set point for the specific filter type used.
Table 8 — Filter Pressure Settings
The filter status switch is factory installed in a filter or filter
mixing box section if ordered in the AHUBuilder®program
when either of the "Factory Wired" control options is selected.
The switch can be factory installed across the first filter section
in the airstream on all types of air-handling units.
The filter switch will typically be factory-installed on the
upstream side of the filter track. The 1/4-in. pneumatic tubing
will be connected to the “low” pressure port and run into the
downstream side of the filter. See Fig. 24.
FILTER TYPE
(Efficiency)
RECOMMENDED MAXIMUM
PRESSURE SETTING
(in. wg)
2-in. Flat (<35%)
2 to 4-in. Flat (35-65%)
Bag/Cartridge (65-85%)
Final (85-98%)
0.5
1.0
1.2
1.5
Fig. 20 — Typical MAT (Mixed-Air Temperature Sensor) Installation
A39-2428EF

17
CF
Fig. 21 — Low-Temperature Thermostat
COIL FINS
SPRING CLIP
AIR
FLOW
NOTE: MOUNTING OF SENSOR
AND CAPILLARY TUBING TO
BE ON LEAVING AIR SIDE OF
COIL (DOWNSTREAM).
CAPILLARY
TUBE
LOW
TEMPERATURE
THERMOSTAT
CONTROL
CABLE ASY.
39M HEATING
COIL SECTION
SPRING
CLIPS
DETAIL “A”
COIL FIN
CAPILLARY
TUBE ON
LEAVING
AIR SIDE
AIRFLOW
COIL FINS
SPRING CLIP
AIR
FLOW
NOTE: MOUNTING OF SENSOR
AND CAPILLARY TUBING TO
BE ON ENTERING AIR SIDE OF
COIL (UPSTREAM).
CAPILLARY
TUBE
LOW
TEMPERATURE
THERMOSTAT
CONTROL
CABLE ASY.
39M COOLING
COIL SECTION
SPRING
CLIPS
DETAIL “A”
COIL FIN AIRFLOW
CAPILLARY
TUBE ON
ENTERING
AIR SIDE
Fig. 23 — Cooling Coil Section, Capillary Tube Routing
Fig. 22 — Heating Coil Section, Typical Capillary Tube Routing for LTT on Heating Only Applications

18
Steam/Water Valves — Steam and water valve assem-
blies are field-supplied and installed. All valves must be fully
modulating and capable of being positioned at any point within
the valve’s travel range.
Valves must be able to accept a 4 to 20 mA or 0 to 10 vdc
control signal.
Field-Supplied Two-Position Water Valves —
The UC Open XP control supports two-position water valves
for heating or CV cooling applications, although it is not rec-
ommended for air handler applications, except if face and
bypass damper control is used.
All water valve assemblies must be field-supplied. For
compatibility, 24 vac type actuators are required. Actuator
power consumption must be rated under 25 va. The actuator
must utilize a spring return method to reposition the valve back
to the normal position if power is removed. Normally open or
normally closed type valves are both acceptable and their
selection depends on the application and specific customer
requirements.
Mixing Box Damper Actuators — The spring re-
turn mixed-air damper actuators are factory-supplied and in-
stalled when ordered in the AHUBuilder®program. When in-
stalled, the actuators are done so directly on the damper jack-
shaft. If more than one damper is located inside of the mixing
box, either separate actuators on each damper or one actuator
with damper linkage can be ordered. Spring return damper ac-
tuators are proportional modulating, direct shaft mount type,
capable of being driven in both directions and holding position
at any point in its travel range. The actuator is mechanically re-
versible. As installed from the factory it provides spring return
closing of the outdoor-air damper on loss of power.
(FLTS) CABLE MARKED No. 3 OR
(FLTS2) CABLE MARKED No. 17
CABLES ROUTED TO TERMINAL BOX OR
CONTROL PANEL LOCATION
AIR
FLOW
39TA51004401
HK06WC031
AL82AR309
CONNECTED TO
LOW PRESSURE INLET
A39-4375
Fig. 24 — Filter Status Switch Installation
CAUTION
To prevent electric shock and equipment damage, discon-
nect the power to the control box before installing any
valve assemblies.
CAUTION
It is extremely important to properly link parallel blade
outdoor-air and parallel blade return-air dampers. Failure to
do so may cause mixing problems, stratification, or coil
freezing under some conditions, especially in combination
type filter mixing boxes. Opposed blade type outdoor-air
dampers are recommended, in conjunction with parallel
blade type return-air dampers. Using these together will
minimize potential problems. See Fig. 25.

19
All factory-mounted actuators ordered with the equipment
are mounted to the outdoor-air damper and have the linkages
preset for spring return closed outdoor air. If the opposite
damper will be used for outdoor air, the actuator must be re-
moved from the damper and re-installed on the opposite damp-
er. The linkages must also be readjusted for proper operation.
The actuators are 24 V with a 2 to 10 VDC output signal and a
4 to 20 mA control signal.
NOTE: For shipping purposes, the secondary connecting rod
which connects the outdoor-air damper to the return-air
damper will be set so that both the outdoor air and return air
dampers remain closed. Before operating the equipment,
loosen the bolt that retains the rod and fully open the return air
damper, then tighten the bolt to lock the rod in position.
For field-mounted actuators, see Fig. 26.
Exhaust Damper Actuator — A separate exhaust/re-
lief damper actuator may be factory-supplied. This damper ac-
tuator is the same make and type of spring return actuator used
for the mixing box dampers and will be factory mounted to the
exhaust damper inside a factory-supplied exhaust box if or-
dered via the AHUBuilder®program. A separate cable is pro-
vided to control the exhaust air damper.
Face and Bypass Damper Actuators — Face and
bypass damper actuators are factory-supplied and installed
when ordered via the AHUBuilder®program. These actuators
are of the same make and type of spring return actuator as the
mixed-air damper actuators.
All face and bypass damper actuators are wired to the UC
Open XP controller using plenum cable. Actuator connections
depend on the application. Refer to Tables 1 and 2 for cable
terminations of face and bypass heating and cooling actuators.
Variable-Frequency Drives — Variable-frequency
drives (VFDs) are used for fan volume control on VAV
units. Variable frequency drives can be factory-supplied.
The input for external frequency input for the variable
frequency drive must accept a 4 to 20 mA signal. The UC
Open XP controller provides an isolated 4 to 20 mA control
signal to the drive. The external start/stop input to the drive
must accept a contact closure. Use 2-conductor, 18 or 20
AWG cable (single-shielded twisted pair or a 3-conductor
shielded cable may be used) to connect the external fre-
quency input and the external start/stop input to the output
of the control.
For VAV units, set the minimum VFD frequency output
(speed at 4 mA external input signal) such that the desired
supply duct static pressure is achieved when all the air
terminals are set to maintain minimum airflow. Verify that the
supply fan status shows the fan status is ON while the supply
fan is operating at the lowest speed. Increase the VFD Mini-
mum Frequency Output Value until the desired static pressure
set point is achieved when the system airflow is at the lowest
possible value.
DX Cooling Control — Direct expansion (DX) cooling
applications are not directly controlled via the UC Open XP.
DX cooling applications are controlled only by the applicable
condenser controller by controlling the staging of the compres-
sors. The supply air temperature (SAT) sensor and the return
air temperature (RAT) sensor in or near the AHU are necessary
inputs for the condenser controller to control the compressor
staging for both digital and standard type scroll compressors.
These sensors are generally wired directly to the condenser's
control module, however they may pass the necessary signal to
the condenser's controller via the UC Open XP and the BAC-
net network. For further information regarding DX control, see
the 39M Control Product Data and the applicable condenser's
control guide.
IMPORTANT: Wire the VFD start/stop input so that if it is
placed in the manual or bypass mode, the low temperature
thermostat is still in the motor control circuit to protect the
unit.
LEGEND
CCW — Counterclockwise
CW — Clockwise
Fig. 25 — Typical Damper Secondary Linkage (Two Parallel Blade Dampers)

20
TOP VIEW
MXB
(REAR AND SIDE)
TOP VIEW
MXB
(REAR AND SIDE)
TOP VIEW
MXB
(SIDE AND SIDE)
(DOWNSTREAM
COMPONENT)
(DOWNSTREAM
COMPONENT)
(DOWNSTREAM
COMPONENT)
(DOWNSTREAM
COMPONENT)
AIRFLOW
AIRFLOWAIRFLOWAIRFLOW
AIRFLOW AIRFLOW
(DOWNSTREAM
COMPONENT)
(DOWNSTREAM
COMPONENT)
LINKAGE
ASY
ANTI-ROTATION
STRAP
ACTUATOR
ACTUATOR
CONTROL
CABLE
MIXED
AIR
SENSOR
MXB
(Top & Rear)
MXB
(Top & Bottom)
MXB
(Rear & Bottom)
MXB
(Top Only)
MXB
(Rear Only)
MXB
(Bottom Only)
Fig. 26 — Actuator Field Mounting
A39-4365