Carrier 11-808-427-01 User Manual

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Introduction .................................................................................................................................................................. 1

Installation ................................................................................................................................................................... 5

Table of Contents

What is the RTU Open controller? ...................................................................................................................... 1

Specifications ........................................................................................................................................................ 3

Safety considerations........................................................................................................................................... 4

Field-supplied hardware ...................................................................................................................................... 5

To mount the RTU Open ....................................................................................................................................... 6

To wire the controller for power.......................................................................................................................... 7

Using the rooftop equipment control power transformer ................................................................... 8

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 ................................................................................................. 11

Wiring specifications ........................................................................................................................... 11

To wire the controller to the network ................................................................................................. 11

Wiring inputs and outputs ................................................................................................................................ 12

Input wiring specifications .................................................................................................................. 13

Inputs ................................................................................................................................................... 14

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 ............................................................................................ 22

Wiring specifications ................................................................................................................ 22

To wire the SAT sensor to the controller ................................................................................. 22

Wiring a Duct Air Temperature sensor ............................................................................................... 22

Wiring specifications ................................................................................................................ 23

To wire a duct sensor to the controller ................................................................................... 23

Wiring an Outdoor Air Temperature sensor ....................................................................................... 23

Wiring specifications ................................................................................................................ 24

To wire an OAT sensor to the controller .................................................................................. 24

Wiring a CO2 sensor ............................................................................................................................ 24

Wiring specifications ................................................................................................................ 25

To wire the CO2 sensor to the controller ................................................................................ 25

Wiring an Outdoor Air Quality sensor ................................................................................................. 26

Wiring specifications ................................................................................................................ 27

To wire the OAQ sensor to the controller ................................................................................ 27

Wiring a Relative Humidity sensor ..................................................................................................... 27

Wiring specifications ................................................................................................................ 28

To wire the RH sensor to the controller................................................................................... 28

Wiring a Humidistat ............................................................................................................................. 28

Wiring specifications ................................................................................................................ 29

To wire a humidistat to the controller ..................................................................................... 29

Wiring an enthalpy switch ................................................................................................................... 29

Wiring specifications ................................................................................................................ 30

To wire an enthalpy switch (outdoor air) to the controller ..................................................... 30

To wire an enthalpy switch (differential) to the controller...................................................... 32

RTU Open i

Table of Contents

Start-up ....................................................................................................................................................................... 36

Sequence of Operation ............................................................................................................................................. 43

Troubleshooting ......................................................................................................................................................... 56

Compliance ................................................................................................................................................................ 58

Appendix A: RTU Open Points/Properties .............................................................................................................. 59

Wiring a status switch ......................................................................................................................... 32

Wiring specifications ................................................................................................................ 32

To wire a status switch to the controller ................................................................................. 33

Wiring a compressor safety ................................................................................................................ 33

Wiring specifications ................................................................................................................ 33

To wire a compressor safety input to the controller ............................................................... 34

Wiring an occupancy switch or door contact ..................................................................................... 34

Wiring specifications ................................................................................................................ 34

To wire an occupancy switch or door contact ......................................................................... 35

Service Test ......................................................................................................................................................... 37

Configuring the RTU Open's properties .......................................................................................................... 38

Unit Configuration properties ............................................................................................................. 38

Setpoint properties.............................................................................................................................. 40

Service Configuration properties ........................................................................................................ 41

Occupancy ........................................................................................................................................................... 43

Supply fan ........................................................................................................................................................... 44

Cooling ................................................................................................................................................................. 44

Economizer ......................................................................................................................................................... 45

Power Exhaust .................................................................................................................................................... 46

Unoccupied Free Cooling .................................................................................................................................. 46

Optimal Start ...................................................................................................................................................... 46

Enthalpy control ................................................................................................................................................. 47

Indoor Air CO2 .................................................................................................................................................... 47

Heating ................................................................................................................................................................ 48

Heat Pump operation ........................................................................................................................................ 49

Dehumidification ............................................................................................................................................... 49

Demand Limiting ............................................................................................................................................... 50

Door contact ....................................................................................................................................................... 50

Remote occupancy ............................................................................................................................................ 50

Fire Shutdown .................................................................................................................................................... 50

Compressor Safety ............................................................................................................................................ 50

Fan Status ........................................................................................................................................................... 51

Filter status ......................................................................................................................................................... 51

Alarms ................................................................................................................................................................. 51

Linkage ................................................................................................................................................................ 53

Linkage Air Source Modes ................................................................................................................................ 55

Serial number ..................................................................................................................................................... 56

LED's .................................................................................................................................................................... 56

Replacing the RTU Open's battery .................................................................................................................. 57

FCC Compliance ................................................................................................................................................. 58

CE Compliance ................................................................................................................................................... 58

BACnet Compliance........................................................................................................................................... 58

Status................................................................................................................................................................... 59

Unit Configuration .............................................................................................................................................. 60

Setpoints ............................................................................................................................................................. 63

Alarm Configuration .......................................................................................................................................... 67

Service Configuration ........................................................................................................................................ 68

Maintenance ....................................................................................................................................................... 70

Alarms ................................................................................................................................................................. 71

ii RTU Open

Table of Contents

Appendix B: Single Point Linkage and Device Address Binding ............................................................................ 75

Index ........................................................................................................................................................................... 77

Linkage ................................................................................................................................................................ 73

I/O Points ............................................................................................................................................................ 73

Single Point Linkage ......................................................................................................................................... 75

Device Address Binding .................................................................................................................................... 76

RTU Open iii

What is the RTU Open controller?

J12

Introduction

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 BACview®6 Handheld or Virtual BACview can be used with the RTU Open controller via the

Access Port. See illustration on the following page.

RTU Open 1

Introduction

2 RTU Open

Specifications

J12

J13

Driver drv_rtuopn_std

Power 24 Vac ±10%, 50–60 Hz

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

Access port

To connect a BACview6 Handheld device, Virtual BACview application, or Field Assistant

Rnet port

For SPT sensors and a BACview6 device 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

device, 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 transient excess voltage/surge events lasting no more than 10 msec.

Status indicators LED's indicate status of communications, running, errors, power, and digital

outputs

RTU Open 3

Introduction

NOTE

Safety considerations

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

Overall dimensions A:

Mounting dimensions 7 mounting holes in various positions

Depth 1-11/16 in. (4.3 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)

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

Field-supplied hardware

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 8). ○ 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).

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

We highly recommend that you mount the RTU Open in the unit control panel!

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.

6 RTU Open

To wire the controller for power

CAUTIONS

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.

• 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.

• Carrier controllers can share a power supply as long as you:

○ Maintain the same polarity ○ Use the power supply only for Carrier controllers

• The RTU Open has an operating range of 21.6 Vac to 26.4 Vac. If voltage measured at the RTU Open's

input terminals is outside this range, the RTU Open may not work properly.

○ 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).

RTU Open 7

Installation

Using the rooftop equipment control power transformer

NOTE

Power

Run

Using an auxiliary control power transformer

must

NOTE

Power

Run

1 Remove power from the 24 Vac transformer. 2 Remove connector assembly from RTU Open's 3 If the rooftop equipment has thermostat connection terminals, connect wiring harness

wire 3 to C. Alternately, connect the control power transformer wires to J1 connector wires 1 (24

and

connector.

wire 1 to R,

Vac) and 3 (Gnd).

4 Apply power to the rooftop equipment. 5 Measure the voltage at the RTU Open’s

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

The harness and connector are keyed and must be oriented properly for correct installation.

7 Verify that the

LED is on and the

LED is blinking.

If you use a separate control power transformer, it is essential that the auxiliary transformer and the rooftop transformer are in-phase. You

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 8 Connect the auxiliary transformer wires to

connector.

wires 1 (24 Vac) and 3 (Gnd).

9 Apply power to the transformer. 10 Measure the voltage at the RTU Open’s

- 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

The harness connectors are keyed and must be oriented properly for correct installation.

12 Verify that the

LED is on and the

. See illustration below.

LED is blinking.

8 RTU Open

Optional

To set the RTU Open's address

CAUTION

* 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

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.

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

off

MSB (SW1) (10's

LSB (SW2) (1's

EXAMPLE

MSB (SW1

LSB (SW2

CAUTION

To set the RTU Open's communications protocol and baud rate

SW3

NOTE

1 Turn 2 Using the rotary switches, set the

the RTU Open's power. The controller reads the address each time you apply power to it.

To set the RTU Open’s address to 01, point the arrow on the

arrow on the

) switch to the ones digit.

) switch to 1.

) switch to the tens digit of the address, and set the

) switch to 0 and the

3 Turn on the RTU Open's power.

The factory default setting is 00 and must be changed to successfully install your RTU Open.

RTU Open's 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

2 Set

it.

DIP switches are used to set the controller's protocol and baud rate. The protocol and speed

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.

Other protocols and baud rates are available. See the RTU Open Integration Guide for additional

instructions.

10 RTU Open

Wiring the RTU Open to the MS/TP network

Wiring specifications

To wire the controller to the network

Gnd

24 Vac

Hot

Net +, Net -

Shield

NOTE

MSTP

NOTE

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.

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.

Cable: 22 AWG or 24 AWG, low-capacitance, twisted, stranded, shielded copper wire

Maximum length: 2000 feet (610 meters)

1 Pull the screw terminal connector from the controller's power terminals labeled 2 Check the communications wiring for shorts and grounds. 3 Connect the communications wiring to the BACnet port’s screw terminals labeled

Use the same polarity throughout the network segment.

4 Verify that the 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.

Use the same baud rate for all controllers on the network segment.

jumper is set to

and

, and

RTU Open 11

Installation

Wiring inputs and outputs

RTU Open Inputs and Outputs Table

Channel Number

Type

Signal

Function

Part Number

Wire/Terminal Numbers

Alternate Terminals

Input 1

4-20 mA

CO2

33ZCT55CO2

33ZCSENSRH-02

N/A

Input 2

4-20 mA

CO2

33ZCT55CO2

33ZCSENSRH-02

J4 -

N/A

Input 3

24 Vac

Compressor Safety **

N/A

J1 -

Input 4

24 Vac

Safety Chain *

N/A

Input 5

24 Vac

Fire Shutdown **

Field-supplied

Input 6

10K

Supply Air Temperature

33ZCSENSAT

J2 - 1 & 2

N/A

Input 7

10K

Outside Air Temperature

33ZCSENOAT

N/A

Input 8

24 Vac

Enthalpy **

33SENTHSW

Input 9

24 Vac

Humidistat **

--HL—38MG-029

N/A

Input 10

10K

Space Temperature

33ZCT55SPT 33ZCT56SPT

J20 - 1 & 2

N/A

Input 11

100K

Space Temperature Setpoint Adjust

33ZCT56SPT 33ZCT59SPT

J20

N/A Rnet

AI Zone Temperature

SPS / SPPL / SPP

J13

N/A

AO - 1

Economizer

Actuator-Field-supplied

N/A

AO - 2

N/A

Not used

N/A

J22

N/A

BO - 1

N/A - Relay

Fan (G)

N/A

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.

OAQ Space Relative Humidity

33ZCT56CO2 33ZCSPTCO2 w/

33ZCASPCO2

- 5 & 6

2 & 3 OAQ Space Relative Humidity

33ZCT56CO2 33ZCSPTCO2 w/

33ZCASPCO2

Thermistor

Fan Status Filter Status Remote Occupancy Door Contact

CRSTATUS005A00 CRSTATUS005A00 Field-supplied Field-supplied

33ZCSENDAT

CRSTATUS005A00 CRSTATUS005A00 Field-supplied Field-supplied

- 9

- 10

- 3 & 2

- 6 & 7

- 7 & 8

- 5 & 6

***

- 3 & 4

***

- 1 & 2

***

12 RTU Open

Thermistor

33ZCT59SPT

- 3 & 4

- 1, 2, 3, 4

- 5 & 4

- 1 & 2

- 4

Channel Number

Type

Signal

Function

Part Number

Wire/Terminal Numbers

Alternate Terminals

BO - 2

N/A - Relay

Heat 2 (W2) Output

N/A

BO - 3

N/A - Relay

Heat 1 (W1) Output

N/A

BO - 4

N/A - Relay

Cool 2 (Y2) Output

N/A

BO - 5

N/A - Relay

Cool 1 (Y1) Output

N/A

BO - 6

N/A - Relay

Humidi-MiZer™

N/A

J11

N/A

BO - 7

N/A - Relay

Reversing Valve

N/A

J11

N/A

BO - 8

N/A - Relay

Power Exhaust

N/A

J11

N/A

Legend

Safety Chain Feedback

Run Enabled

Input wiring specifications

Input

Maximum length

Minimum gauge

Shielding

- Analog Input

- Digital Input

* safeties are utilized. See To wire inputs and outputs (page 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 (Part #OPN-RTUHRN). See To wire inputs and outputs (page

- Analog Output

- Digital Output

- 24 Vac required at this wire to provide

14) for additional information on the RTU Open wiring harness assembly

status. Provide a jumper from J1 - 1 to

14) for additional information.

- 5

- 6

- 7

- 8

- 7 & 8

- 4 & 6

- 1 & 3

- 9 if no

Thermistor 1000 feet

(305 meters)

4-20 mA 3000 feet

(914 meters)

Binary input

1000 feet (305 meters)

SPT (RNET) 500 feet

(152 meters)

22 AWG Unshielded

22 AWG

Unshielded

4 conductor

RTU Open 13

Installation

Inputs

These inputs...

Support this signal type...

Description

Binary outputs

NOTE

Analog output

To wire inputs and outputs

These RTU Open inputs accept the following signal types:

1, 2 4-20 mA The input resistance on the positive (+) terminal is 250 Ohms.

3, 5, 8, 9 Binary (24 Vac) 24 Vac voltage, resulting in a 25 mA maximum sense current

6, 7, 10 Thermistor 10 kOhm at 77° F

11 100k Potentiometer Typically used for 33CZT56SPT Setpoint Offset Potentiometer

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

• Acceptable voltage drop in the wire from the controller to the controlled device

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.

when the contacts are closed

Include the total distance of actual wire. For 2-conductor wires, this is twice the cable length.

• Resistance (Ohms) of the chosen wire gauge

• Maximum current (Amps) the controlled device requires to operate

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.

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.

14 RTU Open

AO - 1

0 - 10 Vdc/4-20 mA

Battery Jumper

In (Do not remove)

Format Jumper*

Out

Input 11 mA Jumper

Out (mA not utilized on this channel)

Input 11 Thermistor

In (default position)

Input 10 mA Jumper

Out (mA not utilized on this channel)

Input 10 Thermistor Jumper

In (default position)

4 Set the appropriate jumpers on the RTU Open.

J3 W1 W2

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

RTU Open 15

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

Installation

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).

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:

16 RTU Open

Compressor Safety

Fan Status

Fire Shutdown

Fan Status

Enthalpy Switch

Fan Status

HumidiStat

Fan Status

Door Contact

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).

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

Filter Status Remote Occupancy Door Contact

J11 Outputs

Filter Status Remote Occupancy Door Contact

Filter Status Remote Occupancy

RTU Open 17

Installation

Wiring sensors to inputs

NOTE

ELECTRICAL SHOCK HAZARD

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.

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

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).

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

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.

18 RTU Open

Field-supplied sensor hardware

Sensor

Part numbers

Notes

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 22)

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

26)

Duct relative humidity sensor

33ZCTSENCO2 Optional with demand control

ventilation

33ZCSENDRH-02

(page 27)

Space relative humidity sensor

33ZCSENSRH-02

(page 27)

Humidistat (page 28) --HL—38MG-029

CO2 aspirator box (page 24) 33ZCASPCO2 Required for CO2 return duct/outside

air applications

Outdoor air enthalpy switch

33CSENTHSW

(page 29)

Return air enthalpy sensor (page 29)

33CSENTSEN Optional with

33CSSENTHSW

Filter status switch (page 32) CRSTATUS005A00

Fan status switch (page 32) CRSTATUS005A00 or field-

supplied

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

RTU Open 19

Installation

Wiring an SPT sensor

Sensor

Part #

Features

SPT Standard

• Local access port

SPT Plus

• Slide potentiometer to adjust setpoint

Local access port

SPT Pro

• LCD display

Local access port

Rnet

NOTES

NOTE

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

• No operator control

SPPL

• MANUAL ON button to override schedule

• LED to show occupied status

•

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

•

You wire SPT sensors to the RTU Open's

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

devices, but no more than 6 devices total

• If you have 2 BACview

devices, the second BACview6 device 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 BACview devices, you must give each a unique address on the Rnet. See the

BACview Installation and User Guide.

Rnet wiring specifications

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

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

20 RTU Open

Wiring: Black, white, green, red

Outer Jacket

Inner insulation

.25 in. (.6 cm)

NOTE

Connect this wire...

To this terminal...

Voltage 300 Vac, power limited

Listing UL: NEC CL2P, or better

To wire the SPT sensor to the controller

1 Partially cut, then bend and pull off the outer jacket of the Rnet cable(s). Do not nick the inner insulation.

Strip about .25 inch (.6 cm) of the inner insulation from each wire.

2 Wire each terminal on the sensor to the same terminal on the controller. See diagram below.

Carrier recommends that you use the following Rnet wiring scheme:

Red

Black

White

Green

+12V

Rnet-

Rnet+

Gnd

RTU Open 21

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