Carrier RTU OPEN 11-808-427-01 Installation manual

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CARRIER CORPORATION ©2010
A member of the United Technologies Corporation family · Stock symbol UTX · Catalog No. 11-808-427-01 · 11/19/2010

RTU Open i
Table of Contents
Introduction.................................................................................................................................................................. 1
What is the RTU Open controller? ......................................................................................................................1
Specifications ........................................................................................................................................................3
Safety considerations...........................................................................................................................................4
Installation ................................................................................................................................................................... 5
Field-supplied hardware ......................................................................................................................................5
To mount the RTU Open.......................................................................................................................................6
To wire the controller for power..........................................................................................................................7
Using the rooftop equipment control power transformer ................................................................... 7
Using an auxiliary control power transformer...................................................................................... 8
To set the RTU Open's address...........................................................................................................................9
To set the RTU Open's communications protocol and baud rate............................................................... 10
Wiring the RTU Open to the MS/TP network................................................................................................. 10
Wiring specifications ...........................................................................................................................11
To wire the controller to the network .................................................................................................11
Wiring inputs and outputs ................................................................................................................................ 12
Input wiring specifications ..................................................................................................................13
Inputs ...................................................................................................................................................13
Binary outputs .....................................................................................................................................14
Analog output ......................................................................................................................................14
To wire inputs and outputs .................................................................................................................14
Wiring sensors to inputs ................................................................................................................................... 18
Field-supplied sensor hardware .........................................................................................................19
Wiring an SPT sensor ..........................................................................................................................20
Rnet wiring specifications........................................................................................................20
To wire the SPT sensor to the controller .................................................................................21
Wiring a Supply Air Temperature sensor............................................................................................21
Wiring specifications ................................................................................................................22
To wire the SAT sensor to the controller .................................................................................22
Wiring a Duct Air Temperature sensor ...............................................................................................22
Wiring specifications ................................................................................................................22
To wire a duct sensor to the controller ...................................................................................23
Wiring an Outdoor Air Temperature sensor .......................................................................................23
Wiring specifications ................................................................................................................23
To wire an OAT sensor to the controller ..................................................................................23
Wiring a CO2 sensor............................................................................................................................24
Wiring specifications ................................................................................................................24
To wire the CO2 sensor to the controller ................................................................................24
Wiring an Outdoor Air Quality sensor .................................................................................................25
Wiring specifications ................................................................................................................26
To wire the OAQ sensor to the controller ................................................................................26
Wiring a Relative Humidity sensor .....................................................................................................26
Wiring specifications ................................................................................................................27
To wire the RH sensor to the controller...................................................................................27
Wiring a Humidistat.............................................................................................................................27
Wiring specifications ................................................................................................................27
To wire a humidistat to the controller .....................................................................................28
Wiring an enthalpy switch...................................................................................................................28
Wiring specifications ................................................................................................................28
To wire an enthalpy switch (outdoor air) to the controller .....................................................29
To wire an enthalpy switch (differential) to the controller......................................................30

Table of Contents
ii RTU Open
Wiring a status switch.........................................................................................................................31
Wiring specifications ................................................................................................................31
To wire a status switch to the controller .................................................................................32
Wiring a compressor safety ................................................................................................................32
Wiring specifications ................................................................................................................32
To wire a compressor safety input to the controller...............................................................33
Wiring an occupancy switch or door contact .....................................................................................33
Wiring specifications ................................................................................................................33
To wire an occupancy switch or door contact.........................................................................34
Start-up.......................................................................................................................................................................35
Service Test......................................................................................................................................................... 36
Configuring the RTU Open's properties .......................................................................................................... 37
Unit Configuration properties .............................................................................................................37
Setpoint properties..............................................................................................................................39
Service Configuration properties........................................................................................................40
Sequence of Operation .............................................................................................................................................42
Occupancy........................................................................................................................................................... 42
Supply fan ........................................................................................................................................................... 43
Cooling................................................................................................................................................................. 43
Economizer ......................................................................................................................................................... 44
Power Exhaust.................................................................................................................................................... 44
Unoccupied Free Cooling .................................................................................................................................. 45
Optimal Start ...................................................................................................................................................... 45
Enthalpy control ................................................................................................................................................. 46
Indoor Air CO2 .................................................................................................................................................... 46
Heating ................................................................................................................................................................ 47
Heat Pump operation........................................................................................................................................ 48
Dehumidification ............................................................................................................................................... 48
Demand Limit..................................................................................................................................................... 49
Door switch ......................................................................................................................................................... 49
Remote occupancy............................................................................................................................................ 49
Fire Shutdown .................................................................................................................................................... 49
Compressor Safety ............................................................................................................................................ 49
Fan Status........................................................................................................................................................... 50
Filter Status ........................................................................................................................................................ 50
Alarms ................................................................................................................................................................. 50
Linkage................................................................................................................................................................ 53
Linkage Air Source Modes................................................................................................................................ 54
Troubleshooting .........................................................................................................................................................55
Serial number..................................................................................................................................................... 55
LED's .................................................................................................................................................................... 55
Replacing the RTU Open's battery .................................................................................................................. 56
Compliance ................................................................................................................................................................57
FCC Compliance................................................................................................................................................. 57
CE Compliance ................................................................................................................................................... 57
BACnet Compliance........................................................................................................................................... 57
Appendix A: RTU Open Points/Properties ..............................................................................................................58
Status................................................................................................................................................................... 58
Unit Configuration.............................................................................................................................................. 59
Setpoints ............................................................................................................................................................. 61
Alarm Configuration .......................................................................................................................................... 65
Service Configuration........................................................................................................................................ 66
Maintenance....................................................................................................................................................... 68
Alarms ................................................................................................................................................................. 70

Table of Contents
RTU Open iii
Linkage................................................................................................................................................................ 71
I/O Points............................................................................................................................................................ 71
Appendix B: Single Point Linkage and Device Address Binding ............................................................................73
Single Point Linkage ......................................................................................................................................... 73
Device Address Binding .................................................................................................................................... 74
Index ...........................................................................................................................................................................75

RTU Open 1
What is the RTU Open controller?
The RTU Open controller is available as an integrated component of a Carrier rooftop unit, or as a field-
installed retrofit product. Its internal application programming provides optimum rooftop performance and
energy efficiency. RTU Open enables the unit to run in 100% stand-alone control mode or it can communicate
to the Building Automation System (BAS).
On board DIP switches allow you to select the baud rate and choose one of the following protocols:
•BACnet
•Modbus
•Johnson N2
•LonWorks
Carrier’s diagnostic display tools such as BACview6Handheld or Virtual BACview can be used with the RTU
Open controller via the J12 Access Port. See illustration on the following page.
Introduction

Introduction
2 RTU Open

RTU Open 3
Specifications
RTU Open driver drv_rtuopn_std
Power 24 Vac ±10%, 50–60 Hz
20 VA power consumption (26 VA with BACview
Access port
attached)
26 Vdc (25 V min, 30 V max)
Single Class 2 source only, 100 VA or less
To connect a BAC
J12
view6Handheld, Virtual BACview
Rnet port
, or Field Assistant
For SPT sensors and a BAC
J13
view6
•1 SPT Plus or SPT Pro
in any of the following combinations, wired
in a daisy-chain configuration:
•1–4 SPT Standards
•1–4 SPT Standards, and 1 SPT Plus or SPT Pro
Any of the above combinations, plus a BACview6,
Comm Option port
but no more than 6 devices
total
For communication with the LonWorks Option Card.
Inputs 12 inputs:
Inputs 1 - 2: 4-20 mA only
Inputs 3, 5, 8, 9: Binary, 24 Vac
Inputs 6 - 7: Thermistor
Inputs 10 - 11: Thermistor
Rnet sensor
Binary outputs 8 relay outputs, contacts rated at 3 A max @ 24 Vac
Configured normally open.
Analog output 1 analog output
AO1: 2 - 10 Vdc or 4-20 mA
Output resolution 10 bit D/A
Real-time clock Battery-backed real-time clock keeps track of time in event of power failure
Battery 10-year Lithium CR2032 battery provides a minimum of 10,000 hours of
data retention during power outages
Protection Incoming power and network connections are protected by non-replaceable
internal solid-state polyswitches that reset themselves when the condition
that causes a fault returns to normal. The power, network, and output
connections are also protected against voltage transient and surge events.
Status indicators LED's indicate status of communications, running, errors, power, and digital
outputs
Environmental operating
range
-40 to 158°F (-40 to 70°C), 10–95% relative humidity, non-condensing
NOTE
Vibration during operation: all planes/directions, 1.5G @ 20–300 Hz
Shock during operation: all planes/directions, 5G peak, 11 ms
Shock during storage: all planes/directions, 100G peak, 11 ms
Controllers should be mounted in a protective enclosure.

Introduction
4 RTU Open
Overall dimensions A:
B:
6-1/2 in. (16.5 cm)
6-1/2 in. (16.5 cm)
Mounting dimensions 7 mounting holes in various positions
Panel depth 2-1/2 in. (6.4 cm)
Weight 11.2 oz (0.32 kg)
BACnet support Conforms to the Advanced Application Controller (B-AAC) Standard Device
Profile as defined in ANSI/ASHRAE Standard 135-2004 (BACnet) Annex L
Listed by UL-873, FCC Part 15-Subpart B-Class A, CE EN50082-1997
Safety considerations
Disconnect electrical power to the RTU Open before wiring it. Failure to follow this warning could cause
electrical shock, personal injury, or damage to the controller.

RTU Open 5
To install the RTU Open:
1 Mount the controller (page 6).
2 Wire the controller for power (page 7).
○Using the rooftop equipment control power transformer (page 7).
○Using an auxiliary control power transformer (page 8).
3 Set the controller's address (page 9).
4 Wire inputs and outputs (page 12).
5 Wire sensors to the controller (page 18).
Field-supplied hardware
An RTU Open retrofit installation may require the following field-supplied components:
•wiring harness: Part #OPN-RTUHRN
•transformer – 24 Vac, 20 VA minimum
•wiring
Application-dependent components:
•carbon dioxide sensors
•damper/damper actuator
•differential pressure switch
•enthalpy switch
•fan status switch
•door switch
•fan section door switch
•relative humidity sensor
•remote occupancy contact
•smoke detector
•temperature sensors
Installation

Installation
6 RTU Open
To mount the RTU Open
When you handle the RTU Open:
•Do not contaminate the printed circuit board with fingerprints, moisture, or any foreign material.
•Do not touch components or leads.
•Handle the board by its edges.
•Isolate from high voltage or electrostatic discharge.
•Ensure that you are properly grounded.
When you mount the RTU Open:
•Do not locate in an area that is exposed to moisture, vibration, dust, or foreign material.
•Follow NEC and local electrical codes.
•Do not obstruct access for unit maintenance.
•Protect from impact or contact during unit maintenance.
We highly recommend that you mount the RTU Open in the unit control panel!

RTU Open 7
Screw the RTU Open into an enclosed panel using the mounting slots on the cover plate. Leave about 2 in. (5
cm) on each side of the controller for wiring.
To wire the controller for power
○The RTU Open is powered by a Class 2 power source. Take appropriate isolation measures when
mounting it in a control panel where non-Class 2 circuits are present.
CAUTIONS
○Do not power pilot relays from the same transformer that powers the RTU Open.
○In most cases, the RTU Open will be powered from the control power transformer provided with the
rooftop equipment. If you must use a separate control power transformer, additional precautions
must be taken to ensure that the auxiliary transformer is in-phase with the rooftop equipment’s
control power transformer. See Using an auxiliary control power transformer (page 8).
Using the rooftop equipment control power transformer
1 Remove power from the 24 Vac transformer.
2 Remove connector assembly from RTU Open's J1 connector.

Installation
8 RTU Open
3 If the rooftop equipment has thermostat connection terminals, connect wiring harness J1 wire 1 to R,
and J1 wire 3 to C. Alternately, connect the control power transformer wires to J1 connector wires 1 (24
Vac) and 3 (Gnd).
4 Apply power to the rooftop equipment.
5 Measure the voltage at the RTU Open’s J1 terminals 1 and 3 to verify that the voltage is within the
operating range of 21.6–26.4 Vac.
6 Attach harness to RTU Open connector J1.
NOTE The harness and connector are keyed and must be oriented properly for correct installation.
7 Verify that the Power LED is on and the Run LED is blinking.
Using an auxiliary control power transformer
If you use a separate control power transformer, it is essential that the auxiliary transformer and the rooftop
transformer are in-phase. You must verify this prior to connecting the auxiliary transformer to the RTU Open.
Follow these steps:
1 Verify the available primary voltage at the rooftop equipment.
2 Remove power from the rooftop equipment and install the appropriate auxiliary transformer. Follow the
manufacturer’s installation instructions.
3 Ground one leg of the auxiliary transformer’s secondary wiring.
4 Apply power to the rooftop equipment. Measure the potential between the rooftop equipment control
power and auxiliary transformer's secondary hot (non-grounded) legs. If the voltage measured is less
than 5 volts, the transformers are in-phase; proceed to step 7. If you measure a voltage greater than 24
Vac, then the phases are reversed.
5 Correct the phase reversal by either of the following methods:
○Remove the ground from the secondary at the auxiliary transformer and connect it to the other
secondary
○Reverse the primary wiring at the auxiliary transformer
6 Repeat step 4 to rewire.
7 Remove connector assembly from RTU Open's J1 connector.
8 Connect the auxiliary transformer wires to J1 wires 1 (24 Vac) and 3 (Gnd).
9 Apply power to the transformer.
10 Measure the voltage at the RTU Open’s J1 - 1and 3to verify that the voltage is within the operating
range of 21.6–26.4 Vac.
11 Attach harness to RTU Open's connector J1. See illustration below.
NOTE The harness connectors are keyed and must be oriented properly for correct installation.
12 Verify that the Power LED is on and the Run LED is blinking.

RTU Open 9
Optional
* Safety chain devices, field-installed - normally closed. Apply 24 Vac to this terminal
(jumper from
J1
- 1 to
J1
- 9) where no safety devices are installed.
** Fire shutdown device, field-installed, configurable as normally open or closed
*** Enthalpy switch, field-installed - configurable as normally open or closed
To set the RTU Open's address
The RTU Open's two rotary switches determine the RTU Open's MAC address when it is placed on an MS/TP
network. The rotary switches define the MAC address portion of the RTU Open's BACnet device instance
number, which is composed of the MS/TP network number and the MAC address. They also set the slave
address on a Modbus or N2 network when less than 100. See the RTU Open Integration Guide for additional
information on integration.
CAUTION The MAC address of the controller must be unique on its network.

Installation
10 RTU Open
1 Turn off the RTU Open's power. The controller reads the address each time you apply power to it.
2 Using the rotary switches, set the MSB (SW1) (10's) switch to the tens digit of the address, and set the
LSB (SW2) (1's) switch to the ones digit.
EXAMPLE To set the RTU Open’s address to 01, point the arrow on the MSB (SW1) switch to 0 and the
arrow on the LSB (SW2) switch to 1.
3 Turn on the RTU Open's power.
NOTE The factory default setting is "00" and must be changed to successfully install your RTU Open.
To set the RTU Open's communications protocol and baud rate
RTU Open's SW3 DIP switches are used to set the controller's protocol and baud rate. The protocol and speed
selection is determined by the network on which the controller will be installed. For Carrier BACnet
implementations, select MS/TP @ 76.8 k as follows:
1 Power down the RTU Open. The controller reads the protocol and baud rate each time you apply power to
it.
2 Set SW3 DIP switches 1, 2, and 4 to On to configure the controller for BACnet MS/TP and 76.8 k baud.
3 Power up the RTU Open.
NOTE Other protocols and baud rates are available. See the RTU Open Integration Guide for additional
instructions.
Wiring the RTU Open to the MS/TP network
The RTU Open 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.

RTU Open 11
Install a BT485 on the first and last controller on a network segment to add bias and prevent signal
distortions due to echoing.
See the MS/TP Networking and Wiring Installation Guide for more details.
Wiring specifications
Cable: 22 AWG or 24 AWG, low-capacitance, twisted, stranded, shielded copper wire
Maximum length: 2000 feet (610 meters)
To wire the controller to the network
1 Pull the screw terminal connector from the controller's power terminals labeled Gnd and 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.
5 Set DIP switches 1 and 2 to the appropriate baud rate. See the MSTP baud diagram on the RTU Open.
The default baud rate is 76.8 kbps.
NOTE Use the same baud rate for all controllers on the network segment.
6 Insert the power screw terminal connector into the RTU Open's power terminals.
7 Verify communication with the network by viewing a module status report.

Installation
12 RTU Open
Wiring inputs and outputs
RTU Open Inputs and Outputs Table
Channel
Number
Type
Signal
Function
Part Number
Wire/Terminal
Numbers
Input 1
Alternate
Terminals
AI 4-20 mA CO2
OAQ
Space Relative Humidity
33ZCT55CO2
33ZCT56CO2
33ZCSENCO2 w/
33ZCASPCO2
33ZCSENSRH-01
J4
N/A
- 5 & 6
Input 2 AI 4-20 mA CO2
OAQ
Space Relative Humidity
33ZCT55CO2
33ZCT56CO2
33ZCSENCO2 w/
33ZCASPCO2
33ZCSENSRH-01
J4
N/A
- 2 & 3
Input 3 BI 24 Vac Compressor Safety **
Fan Status
Filter Status
Remote Occupancy
Door Contact
N/A
33CSAS-01
33CSFS=01
Field-supplied
Field-supplied
J1
- 2
J5
Input 4
- 5 & 6
***
BI 24 Vac Safety Chain * N/A
J1
N/A
- 9
Input 5 BI 24 Vac Fire Shutdown **
Fan Status
Filter Status
Remote Occupancy
Door Contact
Field-supplied
33CSAS-01
33CSFS-01
Field-supplied
Field-supplied
J1
- 10
J5
Input 6
- 3 & 4
***
AI 10K
Thermistor
Supply Air Temperature 33ZCSENSAT
33ZCSENDAT
J2
N/A
- 1 & 2
Input 7 AI 10K
Thermistor
Outside Air Temperature 33ZCSENOAT
J2
N/A
- 3 & 2
Input 8 BI 24 Vac Enthalpy **
Fan Status
Filter Status
Remote Occupancy
Door Contact
33SENTHSW
33CSAS-01
33CSFS-01
Field-supplied
Field-supplied
J2
- 6 & 7
J5
Input 9
- 1 & 2
***
BI 24 Vac Humidistat **
Fan Status
Filter Status
Remote Occupancy
Door Contact
TSTATCCPLH01-B
33CSAS-01
33CSFS-01
Field-supplied
Field-supplied
J5
N/A
- 7 & 8
Input 10 AI 10K
Thermistor
Space Temperature 33ZCT55SPT 33ZCT56SPT
33ZCT59SPT
J20
N/A
- 1 & 2
Input 11 AI 100K
Thermistor
Space Temperature
Setpoint Adjust
33ZCT56SPT 33ZCT59SPT
J20
N/A
- 3 & 4
Rnet AI Zone Temperature SPS / SPPL / SPP
J13
N/A
- 1, 2, 3, 4
AO - 1
AO
Economizer
Economizer
Actuator-Field-supplied
J2
N/A
- 5 & 4
AO - 2
AO
N/A
Not used
N/A
J22
N/A
- 1 & 2
BO - 1 BO N/A - Relay Fan (G) N/A
J1
N/A
- 4
BO - 2 BO N/A - Relay Heat 2 (W2) Output N/A
J1
N/A
- 5
BO - 3 BO N/A - Relay Heat 1 (W1) Output N/A
J1
N/A
- 6
BO - 4 BO N/A - Relay Cool 2 (Y2) Output N/A
J1
N/A
- 7
BO - 5 BO N/A - Relay Cool 1 (Y1) Output N/A
J1
N/A
- 8
BO - 6 BO N/A - Relay Humidi-MiZer™ N/A
J11
N/A
- 7 & 8
BO - 7 BO N/A - Relay Reversing Valve N/A
J11
N/A
- 4 & 6

RTU Open 13
Channel
Number
Type
Signal
Function
Part Number
Wire/Terminal
Numbers
BO - 8
Alternate
Terminals
BO N/A - Relay Power Exhaust N/A
J11
N/A
- 1 & 3
Legend
AI
-Analog Input
AO
- Analog Output
BI
-Digital Input
BO
- Digital Output
*
Safety Chain Feedback
- 24 Vac required at this wire to provide
Run Enabled
status. Provide a jumper from
J1
- 1 to
J1
- 9 if no
safeties are utilized. See To wire inputs and outputs 14(page ) for additional information on the RTU Open wiring harness assembly
terminations.
** Default input function
*** Parallel screw terminal at
J5
(
J5
- 1 =
J2
- 6,
J5
- 3 =
J1
- 10,
J5
- 5 =
J1
- 2) may be used in place of the associated flying leads at
the harness (OPN-RTUHRN). See To wire inputs and outputs 14(page ) for additional information.
Input wiring specifications
Input
Maximum length
Minimum gauge
Thermistor
Shielding
1000 feet
(305 meters)
22 AWG Unshielded
4-20 mA 3000 feet
(914 meters)
22 AWG Unshielded
Binary input
1000 feet
(305 meters)
22 AWG Unshielded
SPT (RNET) 500 feet
(152 meters)
22 AWG
4 conductor
Unshielded
Inputs
These RTU Open inputs accept the following signal types:
These
inputs...
Support this
signal type...
1, 2
Description
4-20 mA The input resistance on the positive (+) terminal is 250 Ohms.
The Aux Power Out terminal is capable of supplying 24 Vdc to
a 4-20 mA transducer, but the total current demanded must
not exceed 40 mA. If the voltage measured from the Aux
Power Out terminal to Gnd is less than 18 Vdc, you need to
use an external power supply.
3, 5, 8, 9 Binary (24 Vac) 24 Vac voltage, resulting in a 25 mA maximum sense current
when the contacts are closed
6, 7, 10 Thermistor 10 kOhm at 77° F
11 100k Potentiometer Typically used for 33CZT56SPT Setpoint Offset Potentiometer

Installation
14 RTU Open
Binary outputs
The RTU Open has 8 binary outputs. You can connect each output to a maximum of 24 Vac/Vdc. Each output
is a dry contact rated at 3 A, 24 V maximum, and is normally open.
To size output wiring, consider the following:
•Total loop distance from the power supply to the controller, and then to the controlled device
NOTE Include the total distance of actual wire. For 2-conductor wires, this is twice the cable length.
•Acceptable voltage drop in the wire from the controller to the controlled device
•Resistance (Ohms) of the chosen wire gauge
•Maximum current (Amps) the controlled device requires to operate
Analog output
The RTU Open has 1 analog output that supports voltage or current devices. The controlled device must share
the same ground as the controller and have input impedance of 500 Ohms maximum for the 4-20 mA mode
on AO - 1.
To wire inputs and outputs
1 Turn off the RTU Open's power.
2 Connect the input wiring to the screw terminals on the RTU Open.
3 Turn on the RTU Open's power.
4 Set the appropriate jumpers on the RTU Open.
AO - 1
J3 0 - 10 Vdc/4-20 mA
Battery Jumper
W1
In (Do not remove)
Format Jumper*
W2 Out
Input 11 mA Jumper
W3 Out (mA not utilized on this channel)
Input 11 Thermistor
W4 In (default position)
Input 10 mA Jumper
W5 Out (mA not utilized on this channel)
Input 10 Thermistor Jumper
W6 In (default position)
*Formatting the controller may result in lost information and should only be done under the guidance of
Carrier Control Systems Support.