Carrier 1-808-427-01 User Manual

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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

RTU Open i

Table of Contents

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

ii RTU Open

Table of Contents

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 iii

Introduction

What is the RTU Open controller?

The RTU Open controller is available as an integrated component of a Carrier rooftop unit, or as a fieldinstalled 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 BACview6 Handheld or Virtual BACview can be used with the RTU Open controller via the

J12 Access Port. See illustration on the following page.

RTU Open 1

Introduction

2 RTU Open

J12

J13

NOTE

Specifications

RTU Open driver drv_rtuopn_std

Power 24 Vac ±10%, 50–60 Hz

20 VA power consumption (26 VA with BACview 26 Vdc (25 V min, 30 V max) Single Class 2 source only, 100 VA or less

attached)

Access port

Rnet port

To connect a BAC

view6 Handheld, Virtual BACview

For SPT sensors and a BAC

, or Field Assistant

view

in any of the following combinations, wired

in a daisy-chain configuration:

• 1 SPT Plus or SPT Pro

• 1–4 SPT Standards

• 1–4 SPT Standards, and 1 SPT Plus or SPT Pro

Any of the above combinations, plus a BACview

but no more than 6 devices

total

Comm Option port

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 Controllers should be mounted in a protective enclosure.

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

RTU Open 3

Introduction

Overall dimensions A:

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

6-1/2 in. (16.5 cm) 6-1/2 in. (16.5 cm)

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.

4 RTU Open

Installation

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

RTU Open 5

Installation

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!

6 RTU Open

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

CAUTIONS

○ 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.

○ 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.

RTU Open 7

Installation

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

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 - 1 and 3 to 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.

must verify this prior to connecting the auxiliary transformer to the RTU Open.

8 RTU Open

Optional

* Safety chain devices, field-installed - normally closed. Apply 24 Vac to this terminal

(jumper from

** 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.

- 1 to

- 9) where no safety devices are installed.

RTU Open 9

Installation

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.

10 RTU Open

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.

RTU Open 11

Installation

Channel Number

Type Signal

Function

Part Number

Wire/Terminal Numbers

Alternate Terminals

33ZCT55CO2

J1 -

J20

J20 J13

AO - 1

Economizer

Actuator-Field-supplied

N/A

AO - 2

N/A

Not used

N/A

J22

N/A

J11

Wiring inputs and outputs

RTU Open Inputs and Outputs Table

Input 1

Input 2 AI 4-20 mA CO2

Input 3 BI 24 Vac Compressor Safety **

Input 4

Input 5 BI 24 Vac Fire Shutdown **

Input 6

Input 7 AI

Input 8 BI 24 Vac Enthalpy **

Input 9

Input 10 AI

Input 11 AI

Rnet AI

BO - 1 BO N/A - Relay Fan (G) N/A

BO - 2 BO N/A - Relay Heat 2 (W2) Output N/A

BO - 3 BO N/A - Relay Heat 1 (W1) Output N/A

BO - 4 BO N/A - Relay Cool 2 (Y2) Output

BO - 5 BO N/A - Relay Cool 1 (Y1) Output

BO - 6 BO N/A - Relay Humidi-MiZer™

BO - 7 BO N/A - Relay Reversing Valve

AI 4-20 mA CO2

OAQ Space Relative Humidity

Fan Status Filter Status Remote Occupancy Door Contact

BI 24 Vac Safety Chain *

Fan Status Filter Status Remote Occupancy Door Contact

BI 24 Vac Humidistat **

10K Thermistor

100K Thermistor

Supply Air Temperature

Outside Air Temperature 33ZCSENOAT

Fan Status Filter Status Remote Occupancy Door Contact

Fan Status Filter Status Remote Occupancy Door Contact Space Temperature 33ZCT55SPT 33ZCT56SPT

Space Temperature Setpoint Adjust Zone Temperature SPS / SPPL / SPP

33ZCT56CO2 33ZCSENCO2 w/

33ZCASPCO2 33ZCSENSRH-01 33ZCT55CO2

33ZCT56CO2 33ZCSENCO2 w/

33ZCASPCO2 33ZCSENSRH-01 N/A 33CSAS-01 33CSFS=01 Field-supplied Field-supplied

N/A

Field-supplied 33CSAS-01 33CSFS-01 Field-supplied Field-supplied 33ZCSENSAT

33ZCSENDAT

33SENTHSW 33CSAS-01 33CSFS-01 Field-supplied Field-supplied TSTATCCPLH01-B 33CSAS-01 33CSFS-01 Field-supplied Field-supplied

33ZCT59SPT 33ZCT56SPT 33ZCT59SPT

N/A

- 5 & 6

- 2 & 3

- 9

- 10

- 1 & 2

- 3 & 2

- 6 & 7

- 7 & 8

- 1 & 2

- 3 & 4

- 1, 2, 3, 4

- 5 & 4

- 1 & 2

- 4

- 5

- 6

- 7

- 8

- 7 & 8

- 4 & 6

N/A

- 5 & 6

***

N/A

- 3 & 4

***

N/A

- 1 & 2

***

N/A

12 RTU Open

Channel Number

Type Signal

Function

Part Number

Wire/Terminal Numbers

Alternate Terminals

J11

Safety Chain Feedback

Run Enabled

J5 (J5

Input Maximum length

Minimum gauge

Shielding

These inputs...

Support this signal type...

Description

BO - 8

Legend

- Analog Input

- Digital Input

* 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 the harness (OPN-RTUHRN). See To wire inputs and outputs 14 (page ) for additional information.

BO N/A - Relay Power Exhaust

- Analog Output

- Digital Output

- 24 Vac required at this wire to provide

- 1 = J2 - 6, J5 - 3 = J1 - 10, J5 - 5 = J1 - 2) may be used in place of the associated flying leads at

N/A

- 1 & 3

status. Provide a jumper from J1 - 1 to

N/A

- 9 if no

Input wiring specifications

Thermistor

1000 feet (305 meters)

4-20 mA 3000 feet

(914 meters)

22 AWG Unshielded

Inputs

Binary input

1000 feet (305 meters)

22 AWG Unshielded

SPT (RNET) 500 feet

(152 meters)

These RTU Open inputs accept the following signal types:

1, 2

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

22 AWG 4 conductor

Unshielded

RTU Open 13

Installation

Battery Jumper

In (Do not remove)

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 4 Set the appropriate jumpers on the RTU Open.

on the RTU Open's power.

AO - 1

W1 W2 W3 W4 W5 W6

*Formatting the controller may result in lost information and should only be done under the guidance of Carrier Control Systems Support.

Format Jumper*

Input 11 mA Jumper

Input 11 Thermistor

Input 10 mA Jumper

Input 10 Thermistor Jumper

0 - 10 Vdc/4-20 mA

Out

Out (mA not utilized on this channel)

In (default position)

Out (mA not utilized on this channel)

In (default position)

14 RTU Open

Optional

* Safety chain devices, field-installed - normally closed. Apply 24 Vac to this terminal

(jumper from

** Fire shutdown device, field-installed, configurable as normally open or closed

*** Enthalpy switch, field-installed - configurable as normally open or closed

J1 - 1 to J1 - 9) where no safety devices are installed.

J4 Inputs

1 Turn off the RTU Open's power. 2 Connect the input and output wiring to the screw terminals on the RTU Open.

NOTE When utilizing the controller's 24 Vdc auxiliary power out, the total current demand for these two

input channels must not exceed 40 mA (100mA per channel).

RTU Open 15

Installation

NOTE J4 Analog Inputs 1 and 2 may be set for the following device types:

○ IAQ Sensor ○ OAQ Sensor ○ Space RH Sensor

J5 Inputs

The terminals for Inputs 3, 5, and 8 are available for use in place of the flying wire leads at Molex

connectors J1 and J2 identified below:

NOTE J5 binary inputs 3, 5, and 8 are the same input channels as:

○ J1 wire 2, J5 - Input - 3 (Compressor Safety) ○ J1 wire 10, J5 - Input - 5 (Fire Shutdown) ○ J2 wire 6, J5 - Input - 8 (Enthalpy Switch).

16 RTU Open

These terminals are available for use in place of the flying wire leads at Molex connectors J1 and J2. Binary inputs are configurable and may be used for the following functions:

Input Default input function Additional functions 3

Compressor Safety

Fire Shutdown

Enthalpy Switch

Fan Status Filter Status Remote Occupancy Door Contact Fan Status Filter Status Remote Occupancy Door Contact Fan Status Filter Status Remote Occupancy Door Contact

J11 Outputs

HumidiStat

Fan Status Filter Status Remote Occupancy Door Contact

RTU Open 17

Installation

NOTE Output relay contacts rated at 3A, 24V maximum. Install pilot relays required by application.

J20 Analog Inputs 10 and 11 are reserved for a 10k Ohm space temperature sensor with an

NOTE

optional 100k Ohm offset potentiometer used for setpoint adjustment.

Wiring sensors to inputs

You may wire various sensors to the RTU Open's inputs. See the table below for details.

NOTE This document gives instructions for wiring the sensors to the RTU Open. For specific mounting and wiring instructions, see the Carrier Sensors Installation Guide.

All field control wiring that connects to the RTU Open must be routed through the raceway built into the corner post. The raceway provides the UL-required clearance between high-and low-voltage wiring.

1 Pass the control wires through the hole provided in the corner post. 2 Feed the wires through the raceway to the RTU Open. 3 Connect the wires to the removable Phoenix connectors. 4 Reconnect the connectors to the board (where removed).

18 RTU Open

Sensor

Part numbers

Notes

NOTE For rooftop unit installation, see the base unit installation instructions.

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could cause personal injury, death, and/or equipment damage.

Disconnect all power to the unit before performing maintenance or service. Unit may automatically start if power is not disconnected.

Field-supplied sensor hardware

The RTU Open controller is configurable with the following field-supplied sensors:

Space temperature sensor (page 20)

Supply air temperature sensor

SPS, SPPL, SPP, 33ZCT55SPT, 33ZCT56SPT, 33ZCT59SPT

33ZCSENSAT Factory-installed

(page 21)

Duct air temperature sensor

33ZCSENDAT

(page 22)

Outdoor air temperature sensor

33ZCSENOAT Factory-supplied with Economizer

(page 23)

CO2 sensor (page 24) 33ZCSENCO2, 33ZCT55CO2,

33ZCT56CO2

Required only for demand control ventilation - a dedicated 24-vac transformer is required

Outdoor air quality sensor (page

25)

Duct relative humidity sensor

33ZCTSENCO2 Optional with demand control

ventilation

33ZCSENDRH-01

(page 26)

Space relative humidity sensor

33ZCSENSRH-01

(page 26)

Humidistat (page 27) TSTATCCPLH01-B

CO2 aspirator box (page 24) C33ZCCASPCO2 Required for CO2 return duct/outside

air applications

Outdoor air enthalpy switch

33CSENTHSW

(page 28)

Return air enthalpy sensor (page 28)

33CSENTSEN Optional with

33CSSENTHSW

Filter status switch (page 31) 33CSFS-01

Fan status switch (page 31) 33CSAS-01 or field-supplied

For specific details about sensors, see the Carrier Sensors Installation Guide.

RTU Open 19

Installation

Sensor

Part #

Features

SPT Standard

•

SPT Plus

•

SPT Pro

• LCD display

Wiring an SPT sensor

The RTU Open is connected to a wall-mounted space temperature sensor to monitor room temperature.

An i-Vu Open Control System offers the following SPT sensors:

SPS

Local access port

• No operator control

SPPL

Slide potentiometer to adjust setpoint

• MANUAL ON button to override schedule

• LED to show occupied status

• Local access port

SPP

• MANUAL ON button to override schedule

• WARMER and COOLER buttons to adjust setpoint

• INFO button to cycle through zone and outside air temperatures,

setpoints, and local override time

• Local access port

You wire SPT sensors to the RTU Open's Rnet port. An Rnet can consist of any of the following combinations of devices wired in a daisy-chain configuration:

• 1 SPT Plus or SPT Pro

• 1–4 SPT Standards

• 1–4 SPT Standards, and 1 SPT Plus or SPT Pro

• Any of the above combinations, plus up to 2 BACview

's but no more than 6 devices total

NOTES

• If you have 2 BACview

's, the second BACview6 must have a separate power supply with the same

ground as the controller.

• If the Rnet has multiple SPT Standard sensors, you must give each a unique address on the Rnet. See

the Carrier Sensors Installation Guide.

• If the Rnet has multiple BACviews, you must give each a unique address on the Rnet. See the BACview

Installation and User Guide.

Rnet wiring specifications

NOTE Use the specified type of wire and cable for maximum signal integrity.

Description 4 conductor, unshielded, CMP, plenum rated cable

Conductor 18 AWG

Maximum length 500 feet (152 meters)

Recommended coloring Jacket: White

Wiring: Black, white, green, red

UL temperature rating 32–167°F (0–75°C)

20 RTU Open

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