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

Outer Jacket

Inner insulation

.25 in. (.6 cm)

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.

NOTE Carrier recommends that you use the following Rnet wiring scheme:

Red

Black

White

Green

+12V

Rnet-

Rnet+

Gnd

Wiring a Supply Air Temperature sensor

Part #33ZCSENSAT

The RTU Open requires a temperature sensor installed in the supply air stream. The Supply Air Temperature (SAT) sensor is used when the rooftop unit is equipped with electric heating.

RTU Open 21

Installation

Wiring specifications

Cable from sensor to controller: If <100 ft (30.5 meters) 22 AWG, unshielded

If >100 ft (30.5 meters) 22 AWG, shielded

Maximum length: 500 feet (152 meters)

To wire the SAT sensor to the controller

1 Connect the wiring harness (OPN-RTUHRN). For details, see To wire inputs and outputs (page 14). 2 Wire the sensor to the wiring harness. See diagram below. 3 Connect to J2 wires 1 and 2. 4 Verify your sensor readings.

Wiring a Duct Air Temperature sensor

Part #33ZCSENDAT

The RTU Open requires a temperature sensor installed in the supply air stream. The Duct Temperature (DAT) sensor is generally used when the rooftop unit is NOT equipped with electric heating.

Wiring specifications

Cable from sensor to controller: If <100 ft (30.5 meters) 22 AWG, unshielded

If >100 ft (30.5 meters) 22 AWG, shielded

Maximum length: 500 feet (152 meters)

22 RTU Open

To wire a duct sensor to the controller

1 Connect the wiring harness (Part#OPN-RTUHRN). For details, see To wire inputs and outputs (page 14). 2 Wire the sensor to the wiring harness. See diagram below. 3 Connect to J2 wires 1 and 2. 4 Verify your sensor readings. 5 Drill .25" diameter hole. Pass sensor leads through bushing and insert assembly into hole. Secure leads

to ductwork with aluminum tape.

NOTE Sensor termination requires installation of RTU Open wiring harness assembly (Part #OPN-RTUHRN).

Wiring an Outdoor Air Temperature sensor

Part #33ZCSENOAT

Outdoor Air Temperature (OAT) is required to utilize all of the RTU Open’s features. OAT may be provided by a local sensor (shown below) or a linked sensor in another controller. See Single Point Linkage (page 73).

Wiring specifications

Cable from sensor to controller: If <100 ft (30.5 meters) 22 AWG, unshielded

Maximum length: 500 feet (152 meters)

If >100 ft (30.5 meters) 22 AWG, shielded

To wire an OAT sensor to the controller

1 Connect the wiring harness (Part#OPN-RTUHRN). For details, see To wire inputs and outputs (page 14). 2 Wire the sensor to the wiring harness. See diagram below.

RTU Open 23

Installation

3 Connect to J2 wires 3 and 4. 4 Verify your sensor readings.

Wiring a CO2 sensor

Part #33ZCSENCO2 (Display model) Part #33ZCT55CO2 (No display)

Part #33ZCT56CO2 (No display)

A CO2 sensor monitors carbon dioxide levels. As CO2 levels increase, the RTU Open adjusts the outside air dampers to increase ventilation and improve indoor air quality. A CO mounted in a return air duct. Duct installation requires an Aspirator Box Accessory (Part #33ZCASPCO2).

The sensor has a range of 0–2000 ppm and a linear 4-20 mA output. The CO2 sensor’s power requirements exceed what is available at

J4 - 1 and 4. Provide a dedicated 24Vac transformer or DC power supply

Wiring specifications

Cable from sensor to controller: If <100 ft (30.5 meters) 22 AWG, unshielded

Maximum length: 500 feet (152 meters)

To wire the CO2 sensor to the controller

sensor can be wall-mounted or

If >100 ft (30.5 meters) 22 AWG, shielded

1 Wire the sensor to the controller. See appropriate diagram below. 2 Install a field-supplied dedicated 24 Vac transformer or DC power supply. 3 Wire the sensor to the controller.

24 RTU Open

Wiring diagram for #33ZCSENCO2:

Wiring diagram for #33ZCT55/56CO2:

Wiring an Outdoor Air Quality sensor

Part #33ZCSENCO2 (Display model)

An outdoor air quality (OAQ) sensor monitors outside air carbon dioxide levels. The RTU Open uses this information, in conjunction with a CO2 sensor, to adjust the outside air dampers to provide proper ventilation. An OAQ sensor is typically duct-mounted in the outside air stream. Duct installation requires an Aspirator Box Accessory (Part #33ZCASPCO2).

RTU Open 25

Installation

The sensor has a range of 0–2000 ppm and a linear 4-20 mA output. The CO2 sensor’s power requirements exceed what is available at

J4 - 1 and 4. Provide a dedicated 24 Vac transformer or DC power supply.

Wiring specifications

Cable from sensor to controller: If <100 ft (30.5 meters) 22 AWG, unshielded

If >100 ft (30.5 meters) 22 AWG, shielded

Maximum length: 500 feet (152 meters)

To wire the OAQ sensor to the controller

1 Wire the sensor to the controller. See appropriate diagram below. 2 Install a field-supplied dedicated 24 Vac transformer or DC power supply. 3 Apply power and verify sensor readings.

Wiring diagram for #33ZCSENCO2:

NOTE Sensor may be terminated at Input 1 or 2.

Wiring a Relative Humidity sensor

Wall sensor - Part #33ZCSENSRH-01 Duct sensor - Part #OPNSENRH-01

The Relative Humidity (RH) sensor may be used for zone humidity control (dehumidification) when applied to a Carrier rooftop unit equipped with the Humidi-MiZer™ option. On units not equipped for dehumidification, the sensor monitors humidity, but provides no control.

NOTE You cannot use a relative humidity sensor when using both a CO2 and OAQ sensor on the controller.

26 RTU Open

Wiring specifications

Cable from sensor to controller: If <100 ft (30.5 meters) 22 AWG, unshielded

Maximum length: 500 feet (152 meters)

To wire the RH sensor to the controller

1 Strip the outer jacket from the cable for at least 4 inches (10.2 cm). Strip .25 inch (.6 cm) of insulation

from each wire.

2 Wire the sensor to the controller. See diagram below. 3 Apply power and verify sensor readings.

If >100 ft (30.5 meters) 22 AWG, shielded

NOTE Sensor may be terminated at Input 1 or 2.

Wiring a Humidistat

Locally Purchased

A humdistat may be used for zone humidity control (dehumidification) when applied to a Carrier rooftop unit equipped with the Humidi-MiZer™ option. On units not equipped for dehumidification, the humidistat will indicate a high humidity condition only.

Wiring specifications

Cable from sensor to controller: If <100 ft (30.5 meters) 22 AWG, unshielded

Maximum length: 500 feet (152 meters)

If >100 ft (30.5 meters) 22 AWG, shielded

RTU Open 27

Installation

To wire a humidistat to the controller

1 Strip the outer jacket from the cable for at least 4 inches (10.2 cm). Strip .25 inch (.6 cm) of insulation

from each wire

2 Wire the humidistat to the controller. See diagram below. 3 Apply power and verify sensor readings.

NOTE Humidistat may be return duct or space mounted.

Wiring an enthalpy switch

Outdoor Air - Part #33CSENTHSW

Return air - Part #33CSENTSEN

The 33CSENTHSW is an outdoor air enthalpy switch/receiver. This control determines the suitability of the outdoor air as a cooling source, based on the heat content of the air. Differential enthalpy control requires installing a 33CSENTSEN enthalpy sensor in the rooftop unit's return air duct.

Wiring specifications

Cable from sensor to controller: If <100 ft (30.5 meters) 22 AWG, unshielded

If >100 ft (30.5 meters) 22 AWG, shielded

Maximum length: 500 feet (152 meters)

28 RTU Open

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

An enhalpy switch is typically mounted in the outdoor air inlet.

Wiring diagram for a field-installed enthalpy switch:

NOTES

• Factory-installed enthalpy switches terminate at J2 wires 6 (switch input) and 7 (24 Vac).

• Input channel must be configured for the enthalpy contact (N.O. or N.C.) that you use.

RTU Open 29

Installation

Wiring diagram for factory-installed enthalpy switch:

NOTE Factory-installed enthalpy switches terminate at J2 wires 6 (switch input) and 7 (24 Vac).

To wire an enthalpy switch (differential) to the controller

30 RTU Open

Wiring diagram for optional enthalpy sensor mounted in the return air for differential enthalpy:

Wiring a status switch

Filter - Part #33CSFS-01 or field-supplied

Fan status - Part #33CSAS-01 or field-supplied

Filter and/or fan status switches may be installed to provide a Dirty Filter indication or Fan Running status.

Wiring specifications

Cable from sensor to controller: If <100 ft (30.5 meters) 22 AWG, unshielded

Maximum length: 500 feet (152 meters)

If >100 ft (30.5 meters) 22 AWG, shielded

RTU Open 31

Installation

To wire a status switch to the controller

NOTES

• Binary inputs 3, 5, 8, and 9 are configurable and may be used for Fan Status, Filter Status, Remote

Occupancy, or Door Contacts, if they have not already been used for their default functions.

• Follow device manufacturer's installation and operating instructions.

Wiring a compressor safety

This is typically provided by the manufacturer with the rooftop equipment. A compressor safety status may be monitored if available.

Wiring specifications

Cable from sensor to controller: If <100 ft (30.5 meters) 22 AWG, unshielded

Maximum length: 500 feet (152 meters)

If >100 ft (30.5 meters) 22 AWG, shielded

32 RTU Open

To wire a compressor safety input to the controller

NOTES

• An isolation relay may be required if the RTU Open is powered separately from the equipment's control

power circuit.

• Follow device manufacturer's installation and operating instructions.

Wiring an occupancy switch or door contact

Occupancy switch - field-supplied

Door contact - field-supplied

Occupancy or door contact switches may be installed to provide an alternate means of occupancy determination or heating and cooling lockout. See Sequence of Operation (page 42) for additional details.

Wiring specifications

Cable from sensor to controller: If <100 ft (30.5 meters) 22 AWG, unshielded

If >100 ft (30.5 meters) 22 AWG, shielded

Maximum length: 500 feet (152 meters)

RTU Open 33

Installation

To wire an occupancy switch or door contact

NOTES

• Binary Inputs 3, 5, 8, and 9 are configurable and may be used for Fan Status, Filter Status, Remote

Occupancy, or Door Contacts - provided they have not been utilized for their default functions.

• Follow device manufacturer's installation and operating instructions.

34 RTU Open

This interface...

Provides a...

i-Vu Open

Field Assistant

Virtual BACview

BACview6 Handheld

BACview6

Start-up

To start up the RTU Open, you need one of the following user interfaces to the controller. These items let you access the controller information, read sensor values, and test the controller.

Permanent interface software

software -

runs on a laptop connected to controller's Local Access port

software -

1, 2

runs on a laptop connected to controller's Local Access port

keypad/display unit -

connects to controller's Local Access port

1, 2

keypad/display unit

connected to controller's Rnet port

Requires a USB Link (USB-L).

See the BACview Installation and User Guide for instructions on connecting and using the above items.

Temporary interface

Permanent interface

RTU Open 35

Start-up

Properties > Equipment > Configuration > Service Configuration > Service Test HOME > CONFIG > SERVICE

TEST

Service Test

Navigation: i-Vu / Field Assistant:

BACview:

Service Test can be used to verify proper operation of compressors, heating stages, indoor fan, power exhaust fans, economizer, and dehumidification. It is highly recommended to use system start-up and during troubleshooting. See Appendix A: Points/Properties (page information.

Service Test differs from normal operation as follows:

• Outdoor air temperature limits for cooling circuits, economizer, and heating are ignored.

• Normal compressor time guards and other staging delays are ignored.

• Alarm statuses (except Fire and Safety Chain) are ignored, but all alarms and alerts are still broadcast on

the network, if applicable.

Service Test can be turned on or off from BACview, Field Assistant, or i-Vu. Select Default Value of Enable to turn on and

Disable to turn off.

NOTES

• Service Test mode is password-protected when accessed from a BACview.

Service Test at initial

58) for more

• Service Test allows testing of each controller output.

• Binary Service Test functions are on when the Default Value is set to Enable and off when set to Disable.

• The output of the Analog Service Test is controlled by the percentage (0-100%) entered into the Default

Value.

• It is recommended to return every Service Test variable to Disable or 0.00 after testing each function

(unless that test variable must be active to test a subsequent function, as in

Compressor 2 Test).

• All outputs return to normal operation when Service Test is set to Disable.

Service Test functions

• Use Fan Test to activate and deactivate the Supply Fan (BO - 1) output. Note that this output may enable

simultaneously with other

Service Test modes even with its Default Value set to Disable.

• Use Compressor 1 Test to activate and deactivate the Compressor 1 (BO - 5) output. The Supply Fan

output will be activated and deactivated in conjunction with this output. Leave

Compressor 1 Test on

Enable if Compressor 2 Test is required.

• Use Compressor 2 Test to activate and deactivate the Compressor 2 (BO - 4) output. Always test the

Compressor 1 output first.

Compressor 1 Test output must be set to Enable for Compressor 2 Test to

function.

• Use the Reversing Valve Test to activate and deactivate the reversing valve (BO - 7) output.

• Use the Dehumidification Test to activate and deactivate the Humidi-MiZer™ (BO - 6) output. The Supply

Fan output will be activated and deactivated in conjunction with the Dehumidification Test output.

• Use Heat 1Test to activate and deactivate the Heat 1 (BO - 3) output. The Supply Fan output is activated

and deactivated in conjunction with the

Heat 1Test output.

• Use Heat 2Test to activate and deactivate the Heat 2 (BO - 2) output. The Supply Fan output is activated

and deactivated in conjunction with the

Heat 2Test output.

36 RTU Open

Navigation:

Properties > Equipment > Configuration > Unit Configuration HOME > CONFIG

UNIT

Point Name/Description

Default/Range

Fan Mode

Auto Continuous

Always On

Occupancy Source

Always Occupied BACnet Schedule BAS On/Off Remote Occ Input

Input 1 Function

• Use Power Exhaust Test to activate and deactivate the power exhaust (BO - 8) output.

• Use Economizer Test to set the (AO - 1) economizer output to any value from 0 to 100% of configured

output (2-10 Vdc or 4-20 mA).

• Analog Output 2 Test (AO - 2) is currently unused and does not require testing.

• Service Test mode does not timeout. Return all test variables to Disable or 0.00. Set Service Test to

Disable or cycle power to the RTU Open to return to normal operation.

Configuring the RTU Open's properties

To start up the RTU Open, you need to configure the properties described in the following sections. These properties affect the unit operation and/or control. Review and understand the meaning and purpose of each property before changing it.

• Unit Configuration properties 37 (page )

• Setpoint Configuration properties 39 (page )

• Service Configuration properties 40 (page )

See Appendix A (page 58) for a complete list of the controller's points/properties.

Unit Configuration properties

i-Vu / Field Assistant: BACview:

– The supply fan's operating mode.

Options:

- The fan cycles on/off in conjunction with heating or cooling.

- The fan runs continuously during occupancy & intermittently during

unoccupied periods with heating or cooling.

- The fan runs continuously regardless of occupancy or calls for heating and

cooling.

- The method that the controller uses to determine occupancy.

Options:

= Controller operates continuously as occupied.

= Controller follows a schedule set up in i-Vu or Field Assistant.

= Occupancy is set over the network by another device or a third party BAS.

=Occupancy is set by a remote contact.

Continuous

Auto Continuous Always On

Always Occupied

Always Occupied BACnet Schedule BAS On/Off Remote Occ Input

D: – The type of sensor (4-20 mA) connected to terminals J4 – 4, 5, & 6.

No Sensor

No Sensor IAQ Sensor OAQ Sensor Space RH Sensor

RTU Open 37

Start-up

Point Name/Description

Default/Range

Input 2 Function

Input 3 Function

Input 3 Switch Configuration

No Function Compressor Safety Fan Status Filter Status Remote Occupancy Door Contact

Input 3

Switch Configuration

Input 5 Function

Input 5 Switch Configuration

No Function Fire Shutdown Fan Status Filter Status Remote Occupancy Door Contact

Input 5

Switch Configuration

Input 8 Function

Input 8 Switch Configuration

No Function Enthalpy Switch Fan Status Filter Status Remote Occupancy Door Contact

Input 8

Switch Configuration

Input 9 Function

Input 9 Switch Configuration

No Function Humidistat Fan Status Filter Status Remote Occupancy Door Contact

– The usage of Input 3. You must also set

Options:

– The input is not used.

– Proves supply fan operation.

– Indicates a dirty filter.

– Sets occupancy using a hardware contact.

terminated at Input

– The usage of Input 5. You must also set

Options:

– The input is not used.

– Fire Safety device status. Inhibits operation when tripped.

– Proves supply fan operation.

– Indicates a dirty filter.

– Sets occupancy using a hardware contact.

terminated at Input

– Safety device status.

– Sets occupancy using a hardware contact.

D: – The type of sensor (4-20 mA) connected to terminals J4 – 1, 2, & 3.

No Sensor

No Sensor IAQ Sensor OAQ Sensor Space RH Sensor

Compressor Safety

No Function Compressor Safety Fan Status Filter Status Remote Occupancy Door Contact

D: – The normal (de-energized) state for the set of contacts

NO/NC (normally open/normally closed)

Fire Shutdown

No Function Fire Shutdown Fan Status Filter Status Remote Occupancy Door Contact

D: – The normal (de-energized) state for the set of contacts

NO/NC (normally open/normally closed)

Options:

terminated at Input

Options:

38 RTU Open

– The usage of Input 8. You must also set

– The input is not used.

– Indicates enthalpy status (high or low).

– Proves supply fan operation.

– Indicates a dirty filter.

– Sets occupancy using a hardware contact.

– The usage of Input 9. You must also set

– The input is not used.

– Indicates high humidity condition.

– Proves supply fan operation.

– Indicates a dirty filter.

– Sets occupancy using a hardware contact.

Enthalpy Switch

No Function Enthalpy Switch Fan Status Filter Status Remote Occupancy Door Contact

D: – The normal (de-energized) state for the set of contacts

NO/NC (normally open/normally closed)

Humidistat

No Function

Humidistat Fan Status Filter Status Remote Occupancy Door Contact

Point Name/Description

Default/Range

Input 9

Switch Configuration

Space sensor type

Navigation:

Properties > Equipment > Configuration > Setpoints HOME > CONFIG > SETPOINT

Heating

Cooling

Point Name/Description

Default/Range

Occupied Heating

Occupied Cooling

Unoccupied Heating

Unoccupied Cooling

terminated at Input

Setpoint properties

i-Vu / Field Assistant: BACview:

Select a color band on the setpoint graph to see the current setpoints in the descriptions below.

and

D: – The normal (de-energized) state for the set of contacts

NO/NC (normally open/normally closed)

D: - The type of local space temperature sensor.

T55

T55 T56 (Use for T59) SPT Sensor None

fields. See setpoint

The heating setpoint the controller maintains while in occupied mode.

The cooling setpoint the controller maintains while in occupied mode.

The heating setpoint the controller maintains while in unoccupied mode.

The cooling setpoint the controller maintains while in unoccupied mode.

RTU Open 39

D: – Green

D: – Gray

70°F

-40 to 245°F

74°F

-40 to 245°F

55°F

45 to 100°F

90°F

-40 to 245°F

Start-up

Point Name/Description

Default/Range

Optimal Start

Occ Relative Humidity Setpoint

Unocc Relative Humidity Setpoint

DCV Max Ctrl Setpoint

Power Exhaust Setpoint

Configuration >Service Configuration

Economizer Exists

Yes

Configuration >Service Configuration > Continuous Occupied Exhaust

Navigation:

Properties > Equipment > Configuration > Service Configuration HOME > CONFIG > SERVICE

Point Name/Description

Default/Range

Unit Type

Heat/Cool HP O/B Ctrl

HP Y1/W1 Ctrl

Compressor Stages Economizer Exists

Yes

Reversing Valve Output

O = Reversing Valve

B =

Reversing Valve

Heat Type

Number Of Heat Stages

may begin to adjust the effective setpoints to achieve the occupied setpoints by the time scheduled occupancy begins. Enter 0 to disable Optimal Start.

– The percentage of relative humidity in the space during

occupancy that will energize BO - 6 (Humidi-MiZer™).

the unoccupied time period that starts the unit and energizes BO - 6 (Humidi-MiZer™).

- The outside air damper position at which the controller energizes the Power Exhaust relay. set to be set to

, and

must be

Service Configuration properties

i-Vu / Field Assistant: BACview:

must

4 hr

D: – The earliest time, prior to occupancy, at which the Optimal Start function

0 to 4 hr

60%rh

0 to Unoccupied RH Control Setpoint

D: – The percentage of relative humidity in the space during

95%

30 to 100%

D: – The design difference between indoor and outdoor CO2 levels.

650ppm

0 to 9999 ppm

50% Open

20 to 90% Open

– The type of equipment that the RTU Open is controlling.

Options:

– Standard rooftop air handling unit.

– Heat Pump application, uses reversing valve output to control heating and

cooling.

– Carrier Heat Pump application only.

economizer damper.

output on with heating.

– The type of heating that the unit has. D:

– The number of mechanical cooling stages. D:

– Set to

output on with cooling. Set to

– The number of heat stages. D:

Heat/Cool

Heat/Cool HP O/B Ctrl HP Y1/W1 Ctrl

One Stage

One Stage Two Stages

D: to enable economizer control for units equipped with an

No/Yes

R: O O / B

Electric

Electric/Gas

R: 2 1 /2 /0 (no heating)

40 RTU Open

Point Name/Description

Default/Range

Continuous Occupied Exhaust

Yes

Power Exhaust Setpoint.

Indoor CO2 Sensor Value @min (ma)

Indoor CO2 Sensor Value @max (ma)

The CO2 value that corresponds to a 20mA input at

Outdoor CO2 Sensor Value @min (ma)

Outdoor CO2 Sensor Value @max (ma)

– Configures the exhaust fan control strategy (BO-8). If

the power exhaust runs continuously in occupied mode and is off in unoccupied mode. If

, the power exhaust is controlled by the

the appropriate input channel.

at the appropriate input channel.

No/Yes

D: – The CO2 value that corresponds to a 4mA input at

0ppm

0 to 9999 ppm

D: –

2000 ppm

0 to 9999 ppm

D: – The CO2 value that corresponds to a 4 mA input

0ppm

0 to 9999 ppm

D: – The CO2 value that corresponds to a 20 mA input

2000 ppm

0 to 9999 ppm

RTU Open 41

Sequence of Operation

The RTU Open supports various types of constant volume air source configurations:

• Standard heat/cool unit types with up to 2-stages of mechanical cooling and gas or electric heating

• Heat pump units utilizing a reversing valve output for heating and cooling control

• Heat pump unit (Carrier) with an OEM control board

• Economizer, CO2, Demand Limiting, and RH control strategies are available for appropriately equipped

units

The RTU Open may operate as part of a linked VVT system or as a stand-alone controller.

Occupancy

The RTU Open’s operation depends upon its occupancy state (Occupied/Unoccupied). The RTU Open operates continuously in the

Occupied mode until you configure an occupancy schedule.

An occupancy schedule may be:

• A local schedule configured in the controller using BACview or Field Assistant

• A BACnet schedule configured in i-Vu, networked through an i-Vu Open Router

• A BACnet or local schedule configured for subordinate VVT Zones, networked through an i-Vu Open

Router(s) and employing Linkage

To set up occupancy schedules, consult the documentation for your user interface.

NOTE A BACnet schedule, downloaded from i-Vu will overwrite a local schedule that was set up with BACview or Field Assistant.

Occupancy Source - the following settings determine occupancy. See Unit configuration (page 59).

Options:

• Always Occupied – Controller operates continuously, regardless of any configured schedule

• BAS On/Off – Occupancy is set over the network by another device or a third party BAS. Refer to the RTU

Open Integration Guide for additional instructions in communication protocols.

• Remote Occ Input – Controller monitors an input contact connected to one of the available binary inputs

configured to receive it. You must set one

Input Switch Configuration to Remote Occupancy.

Unit Configuration > Occupancy Source to Remote Occ Input and

42 RTU Open

Supply fan

The RTU Open supply fan may be configured for one of three Fan Modes:

• Auto - The fan cycles on/off in conjunction with heating or cooling

• Continuous - The fan runs continuously during occupancy and intermittently during unoccupied periods

• Always On - The fan runs continuously regardless of occupancy or calls for heating and cooling

Occupancy can be determined by Linkage, BACnet schedules, BAS schedules, or in response to a remote occupancy switch.

A Unit Start Delay is used when transitioning from Unoccupied to Occupied. A Fan Off Delay allows the supply fan to continue operating after heating or cooling stops.

If the following alarms are active, the fan turns off immediately, regardless of the occupancy state or demand:

•

The RTU Open does not include smoke-control functions such as smoke-purge, zone-pressurization, or smokeventilation. Each of these modes require a field-designed circuit to operate the following, as required by local fire codes:

• RTU supply fan

• RTU economizer

• RTU power exhaust

The RTU Open may be configured to accept a Supply Fan Status input to provide proof the supply fan is operating. When enabled, a loss or lack of fan status will stop heating and cooling operation.

A Supply Fan Alarm Service Timer function is available to track the number of supply fan run hours and generate an alarm when the accumulated runtime exceeds the set threshold.

with heating or cooling

Fire Shutdown Safety chain SAT

alarm

alarms

SPT

Cooling

The RTU Open's application and configuration determines the specific cooling sequence. The RTU Open can control up to two stages of cooling with an additional output for a reversing valve (heat pump applications).

The following conditions must be true for the cooling algorithm to operate:

• Outdoor Air Temperature is greater than the Cooling Lockout Temperature setpoint

• The indoor fan has been on for at least 30 seconds

• The unit has a valid Supply Air Temperature input

• The unit has a valid Space Temperature input

• Heat mode is not active and the time guard between modes has expired

• Economizer is active and open > 85% with SAT > (Minimum Cooling SAT + 5°F) and SPT > Effective

Cooling Setpoint + 0.5°F, or the Economizer is unavailable

RTU Open 43

Sequence of Operation

The cooling relays are controlled by the Cooling Control PID Loop and Cooling Stages Capacity algorithm. They calculate the desired number of stages needed to satisfy the space by comparing the

Space Temperature to

the:

• Effective Occupied Cooling Setpoint when occupied

• Effective Unoccupied Cooling Setpoint when unoccupied

When the cooling algorithm preconditions have been met, the compressors are energized in stages, as applicable. Anti-recycle timers are employed to protect the equipment from short-cycling. There are fixed three-minute minimum on-times, and five-minute off-times for each compressor output.

During compressor operation, the RTU Open may reduce the number of active stages if the rooftop supply air temperature falls below the started again after the normal time-guard period has expired, if the above the

Minimum Cooling SAT Setpoint.

Minimum Cooling SAT Setpoint. A compressor staged off in this fashion may be

Supply Air Temperature has increased

Compressor 2 Service Alarm Timer functions are available (one for each stage of compression). This function

tracks the number of compressor run hours and generates an alarm when the accumulated runtime exceeds the threshold set by the adjustable compressor service alarm timers.

Economizer

The RTU Open provides an analog economizer output for rooftop units with economizer dampers. Economizer dampers may be used to provide free cooling and indoor air quality control when outside air conditions are suitable.

The following conditions must be true for economizer operation:

• The Outdoor Air Temperature is less than the Space Temperature and less than the Economizer High

OAT Lockout Temp setpoint

• The indoor fan has been on for at least 30 seconds

• The unit has a valid Supply Air Temperature input

• The unit has a valid Space Temperature input

If any of the preceding conditions are not true, the economizer will be set to the Vent Dmpr Pos / DCV Min Pos setpoint.

If all preceding conditions are true, the economizer PID loop will modulate the damper from the Vent Dmpr Pos / DCV Min Pos setpoint.

The economizer moves to the Vent Dmpr Pos / DCV Min Pos setpoint if the SAT falls below the Minimum Cooling SAT (+ 5°F).

Power Exhaust

The RTU Open may enable and disable an exhaust fan, based on either the controller’s occupancy or its economizer damper position.

If Continuous Occupied Exhaust is Yes, the Power Exhaust binary output (BO-8) is energized while theRTU Open is occupied and de-energized when unoccupied.

If Continuous Occupied Exhaust is No, the Power Exhaust binary output (BO-8) is energized when the economizer damper output exceeds the energized until the economizer output falls below the 10%.

Power Exhaust Setpoint value (default = 50%). The output remains

Power Exhaust Setpoint value by a fixed hysteresis of

44 RTU Open

Unoccupied Free Cooling

Unocc Free Cool Enable allows rooftop equipment with an economizer damper to utilize outdoor air for free

cooling during unoccupied periods.

The following conditions must be true for unoccupied free cooling to operate:

• Unocc Free Cool Enable set to Enable

• The system is unoccupied

• The outside air temperature is below the Economizer High OAT Lockout Temp setpoint

• The outside air temperature is less than the space temperature

• Enthalpy (if enabled) is Low

When the RTU Open schedule is unoccupied and the space temperature rises at least 1° above the Occupied Cooling Setpoint, the supply fan starts. The economizer damper opens as necessary to cool the space. The

RTU Open continues to operate in this mode until the space is satisfied or the outside air conditions are no longer suitable for free cooling.

Optimal Start

The RTU Open may utilize Optimal Start. Optimal Start adjusts the effective setpoints to achieve the occupied setpoints by the time scheduled occupancy begins.The Optimal Start recovery period may begin as early as 4 hours prior to occupancy. The algorithm works by moving the unoccupied setpoints toward the occupied setpoints. The rate at which the setpoints move is based on the outside air temperature, design temperatures, and capacities.

The following conditions must be true for unoccupied free cooling to operate:

• On the Properties page > Equipment tab > Configuration > Setpoints > Optimal Start, the Default Value

must be set greater than

• The system is unoccupied

NOTE If the Open controller does not have a valid outside air temperature, then a constant of 65° F is used. This value is not adjustable.

0 and less than or equal to 4 (0.00 disables Optimal Start).

RTU Open 45

Sequence of Operation

The actual equation that the controller uses to calculate Optimal Start is nonlinear. An approximation of the result is shown below.

To change Optimal Start settings:

1 In the navigation tree, select the equipment that you want to change. 2 Click Properties page > Equipment tab > Configuration > Setpoints.

Enthalpy control

You may use an enthalpy switch to indicate the suitability of outdoor air for economizer cooling. You can use either an outdoor air or differential enthalpy switch. A differential enthalpy switch has a sensing device in both the outdoor and return air streams. A differential enthalpy switch indicates when outside air is cooler than the return air, and is available for economizer cooling. If no enthalpy switch is configured, a network point (Object Name: oae) is available. This point is displayed in i-Vu and BACview as

The sequence of operation for economizer cooling is the same with or without an enthalpy switch, except that an enthalpy switch imposes one more validation on the suitability of outside air for economizer cooling. An Enthalpy Status that is High disables the economizer and the outside air damper goes to its minimum position. An preconditions are met.

Indoor Air CO2

Enthalpy (BACnet).

Enthalpy Status that is Low enables the economizer if a call for cooling exists and the remaining

Indoor Air CO2 is controlled on rooftop equipment with an economizer. Indoor Air CO2 sequence is enabled

by installing an air quality (CO2) sensor. A CO2 sensor may be terminated at the RTU Open, or a subordinate zone controller, when part of a zoned system.

An outdoor air quality sensor may also be installed and terminated at the RTU Open, but it is not required. When an outdoor air quality sensor is not installed, the algorithm uses 400ppm as the fixed outdoor air CO2 level.

46 RTU Open

The following conditions must be true for the Indoor Air CO2 algorithm to operate:

• The system is occupied

• The supply fan has been started for at least 30 seconds

• The CO2 sensor has a valid reading

As the air quality within the space changes, the minimum position of the economizer damper changes, which allows more or less outdoor air into the space, depending on the relationship of the indoor air CO2 level to the differential setpoint.

The Indoor Air CO2 algorithm calculates a minimum position value using a PID loop. The CO2 minimum damper position is then compared against the

Vent Dmpr Pos / DCV Min Pos setpoint and the greatest value

becomes the final minimum damper position of the economizer output.

The degree to which the outside air damper may be opened by the Indoor Air CO2 algorithm is limited by the

DCV Max Vent Damper Pos setpoint, which is adjustable between ten and sixty percent (10 – 60%).

Heating

The specific heating sequence is determined by the controller's application and configuration. The RTU Open controls up to two stages of gas or electric heating with an additional output for a

Reversing Valve (Heat

Pump applications).

The following conditions must be true for the heating algorithm to operate:

• The Outdoor Air Temperature is less than the Heating Lockout Temperature setpoint

• The indoor fan has been ON for at least 30 seconds

• The unit has a valid Supply Air Temperature input

• The unit has a valid Space Temperature input

• Neither Cool mode nor economizer are active and the time guard between modes has expired

The heating relays are controlled by the Heating Control PID Loop and Heating Stages Capacity algorithm, which calculate the desired number of stages to satisfy the space by comparing the

Space Temperature to

the:

• Effective Occupied Heating Setpoint when occupied

• Effective Unoccupied Heating Setpoint when unoccupied

When the heating algorithm preconditions have been met, the heating is energized in stages. Anti-recycle timers are employed to protect the equipment from short-cycling. There are fixed one minute minimum on and off times for each heating output.

During heating operation, the RTU Open may reduce the number of active stages if the rooftop Supply Air Temperature exceeds the Maximum Heating SAT setpoint. A heat stage turned off in this fashion may be started again after the normal time-guard period has expired, if the below the

Maximum Heating SAT setpoint.

Supply Air Temperature has decreased

RTU Open 47

Sequence of Operation

Heat Pump operation

The RTU Open can control heat pumps HP O/B and Y1/W1.

HP O/B provides a separate output (BO-7) to control a reversing valve. The reversing valve control may be

configured to be energized with a call for heating

(B), or energized with a call for cooling (O).

The sequence of operations are as previously described for heating and cooling except that the Y1 and Y2 outputs are compressor outputs, energizing mechanical heating or cooling, depending on the state of the reversing valve.

W1 and W2 are used for auxiliary heat. Up to two stages are available.

Selection Y1/W1 is for heat pumps that do not require a O terminal to energize the reversing valve. The sequences of operations are as described for Heating (page output is not utilized in this application.

W1 and W2 are used for auxiliary heat. Up to two stages are

47) and Cooling (page 43). The reversing valve

available.

Dehumidification

The RTU Open provides occupied and unoccupied dehumidification on units that are equipped with the Carrier Humidi-MiZer™ option from the factory. This requires a space relative humidity sensor or a humidistat for control.

The following conditions must be true for the dehumidification control to operate:

• The Outside Air Temperature is greater than the Cooling Lockout Temperature setpoint

• The Indoor Fan has been ON for at least 30 seconds

• The unit has a valid Supply Air Temperature input

• The unit has a valid Space Temperature input

• The unit has a valid Space Relative Humidity Sensor or Humidistat input

• Heat mode is not active and the time guard between modes has expired

When using a relative humidity sensor to control dehumidification, occupied and unoccupied dehumidification setpoints are used.

When using a humidistat, the setpoints are not used. The humidistat indicates a high-humidity condition.

When a high indoor relative humidity condition is indicated and the above conditions are satisfied, the RTU Open enters the dehumidification mode, energizing the Humidi-MiZer™ output.

The mode continues until the space relative humidity falls below the active setpoint by a 5% fixed Hysteresis when a humidity sensor is used, or when there is no longer a call for dehumidification where a humidistat is used.

See the base unit / Humidi-MiZer™ operations manual for additional information.

48 RTU Open

Demand Limit

The RTU Open may employ a demand limit strategy. Demand limiting in the RTU Open works through setpoint expansion. The controller’s heating and cooling setpoints are expanded in steps or levels. The degree to which the setpoints are expanded is defined by the

Each Demand Level (1 through 3) adjusts the heating and cooling setpoints outwards. By default, Demand 1 yields a 1° expansion,

The BACnet Demand Limit variable sets the desired level of setpoint expansion in the receiving controller. Level 0 leaves the standard occupied and unoccupied heating and cooling setpoints in effect. Levels 1 through 3 expands occupied heating and cooling setpoints.

Door switch

A Door Contact may be configured on any unused binary input. A typical application is an occupancy sensor mounted within the space served by a single zone rooftop. electric or gas heating, when active. Economizer cooling, if available, continues to operate.

Demand Level Setpoints.

Demand 2 yields a 2° expansion, and Demand 3 yields a 4° expansion.

Door Contact disables mechanical cooling and

Remote occupancy

Remote occupancy may be configured on any unused binary input channel. A typical application is a remote

contact, controlled by a third party, to set the controller's occupied mode. The requires both an input configured for operate.

Once configured, the controller will operate in the occupied or unoccupied mode, as determined by the state of the

Remote Occupancy input.

Fire Shutdown

Fire Shutdown may be configured on Binary Input 5. A typical application involves a smoke detector or fire

shutdown contact, which, when active, immediately shuts down equipment operation.

Compressor Safety

Compressor Safety may be configured on Binary Input 3. A compressor safety tripped indicator circuit is

available on most Carrier rooftop equipment.

A Compressor Safety Alarm is shown on Properties page > Equipment tab > Alarms and indicates that the equipment requires attention.

Remote Occupancy function

Remote Occupancy, and Occupancy Source set to Remote Occ Input to

RTU Open 49

Sequence of Operation

Cooling, heating, and supply fan outputs are not interrupted except where the RTU Open is configured for Heat Pump operation. When configured for Heat Pump, and in the heating mode, a compressor safety fault will cause the available stages of electric heating to be enabled in place of mechanical heating.

Normal operation resumes when the compressor safety circuit is de-energized.

Fan Status

Fan Status may be configured on any unused binary input channel. A typical application would be an airflow

switch, current sensing relay, or other device that provides a supply fan running verification.

Enabling this function displays the supply fan’s status on the equipment graphic.

If the controller loses fan status during operation, heating and cooling are disabled, the economizer damper (if available) is closed, and an alarm for loss of status is indicated.

If the fan status is on when the controller is commanding the fan off, the unit remains in the off state. An alarm is generated indicating that the fan is running when it should be off.

Filter Status

Alarms

Filter status may be configured on any unused binary input channel. A typical application is a differential

pressure switch that senses the pressure drop across a filter bank.

When the pressure across the filter bank exceeds the setpoint of the differential pressure switch, the Filter status is displayed as

NOTE Some of the Alarms functions described in this section will only be visible on the Properties page > Equipment tab > Alarms when the appropriate inputs are configured. Alarms are not initiated when the input

is not configured.

Safety Chain - You may use the RTU Open's safety chain circuit to shut down the unit for a safety condition. Examples: Low or High Temperature Cutouts (Freezestat / Firestat). See To wire inputs and outputs (page for additional wiring instructions. This alarm indicates the safety chain circuit (Input 4) is open. Cooling, heating, and supply fan operation stop after appropriate time guards. Normal operation resumes when the safety chain circuit is complete.

Fire Shutdown – You may configure the RTU Open to accept a Fire Shutdown contact on Input 5. Examples: Smoke detectors or fire shutdown relays. This alarm indicates this device (Input 5) has tripped. Cooling, heating, and supply fan operation immediately stop. Reset fire shutdown contact to resume normal operation.

Compressor Safety – You may configure the RTU Open to monitor the base unit’s compressor safety circuit. This alarm indicates the base unit's compressor safety circuit is energized. Cooling, heating, and supply fan outputs are not interrupted except when the RTU Open is configured for Heat Pump. Normal operation resumes when the compressor safety circuit is de-energized.

If the Heat Pump is in the heating mode, it will automatically replace the compressor stage(s) with the equivalent number of auxiliary heat stages, as available.

• If it's a Carrier Heat Pump, there is only one auxiliary heat stage output and the staging is done by the

machine itself, if it's two-stage gas or electric.

Dirty on the controller graphic. An alarm indicates a dirty filter.

14)

50 RTU Open

• For a non-Carrier Heat Pump, when configured for two stages of aux heat and two compressors,

Compressor 1 is replaced by Aux Heat Stage 1 and Compressor 2 is replaced by Aux Heat Stage 2.

The compressor output stays on when the safety alarm is present. For cooling, the alarm indicates the compressors are down. See Heat Pump operation (page 48) for further information.

Space Temp Sensor – This alarm indicates an invalid sensor condition in a physically connected space temperature sensor (SPT Sensor/T5*). Cooling, heating, and supply fan operation stop after the appropriate time guards. Normal operation resumes when the controller detects a valid sensor.

Supply Air Temp Sensor – This alarm indicates a shorted or open circuit in the SAT input. Cooling, heating, and supply fan operation stops after the appropriate time guards. Normal operation resumes when the controller detects a valid sensor.

Outdoor Air Temp Sensor Alarm - This alarm indicates a shorted or open circuit in the OAT input. Cooling, heating, and supply fan operation continues. OAT lockouts will not operate while the sensor is in alarm. Normal operation resumes when the controller detects a valid sensor.

Space Relative Humidity Sensor - This alarm indicates if the mA input at the associated channel falls below

3.5 mA or rises above 21 mA. Cooling, heating, and supply fan operation continues, however, the controller’s Humidi-MiZer™ binary output is disabled until the fault condition is corrected.

IAQ Sensor - The RTU Open generates an IAQ Sensor alarm if the mA input at the associated channel falls below 3.5 mA or rises above 21 mA. Cooling, heating, and supply fan operation continues. However, the controller’s IAQ control function is disabled until the fault condition is corrected.

OAQ Sensor - The RTU Open generates an OAQ Sensor alarm if the mA input at the associated channel falls below 3.5 mA or rises above 21 mA. Cooling, heating, and supply fan operation continues. However, the controller’s IAQ control function uses 400ppm as the fixed outdoor air CO2 level until the fault condition is corrected.

Space Temperature –

• Occupied - The RTU Open generates a Low Space Temperature alarm if the space temperature falls

below the lower limit of the blue color bar. A

High Space Temperature alarm is generated if the space

temperature rises above the upper limit of the orange color bar.

• Unoccupied An unoccupied low space temperature alarm is generated when the space temperature falls

below the temperature alarm is generated when the space temperature rises above the

Alarm Configuration > Unoccupied Low SPT Alarm Limit. An unoccupied high space

Alarm Configuration >

Unoccupied High SPT Alarm Limit.

The following values are related to the Space Temperature alarm:

• Alarming Temperature – This variable displays the value of the space temperature that is in alarm and is

only visible when the space temperature is in an alarm state.

• Alarm Limit Exceeded – This variable displays the value of the alarm setpoint that is exceeded by the

alarming space temperature and is only visible when the space temperature is in an alarm state.

High Supply Air Temperature – The RTU Open generates this alarm when the supply air temperature exceeds the

Alarm Configuration > High SAT Alarm Limit setpoint for 5 minutes. This alarm is inhibited until the RTU

has been running for 30 minutes to allow for system stabilization after startup.

Low Supply Air Temperature - The RTU Open generates this alarm when the supply air temperature falls below the

Alarm Configuration > Low SAT Alarm Limit setpoint for 5 minutes. This alarm is inhibited until the

RTU has been running for 30 minutes to allow for system stabilization after startup.

Setpoint Slider – The RTU Open generates this alarm when an open circuit is detected at Input 11 and the RTU Open

Configuration > Unit Configuration > Input Configuration > Space sensor type is set to T56. Note that only an open circuit results in an alarm. A short across this input offsets the setpoints negatively by the amount configured in the

Unit Configuration > Setpoint Adjustment Range.

Switch Configuration - The RTU Open generates this alarm when any two of the Unit Configuration > Input Functions 3, 5, 8, or 9 are configured identically. Neither input may work reliably and downstream control may

be affected, depending on the function duplicated. The alarm clears and normal control is restored when the input function duplication is corrected.

Analog Input Configuration - The RTU Open generates this alarm when the Unit Configuration > Input

RTU Open 51

Sequence of Operation

Functions 1 and 2 are configured identically. Neither input may work reliably and downstream control may be affected, depending on the function duplicated. The alarm clears and normal control is restored when the input function duplication is corrected.

High Space Relative Humidity - The RTU Open generates this alarm when the space humidity exceeds the Alarm Configuration > High Space Humidity Alarm Limit setpoint for 10 minutes. This alarm is inhibited until

the RTU runs for 15 minutes to allow for system stabilization after startup.

Low Space Relative Humidity - The RTU Open generates this alarm when the space humidity falls below the Alarm Configuration > Low Space Humidity Alarm Limit setpoint for 5 minutes. This alarm is inhibited until

the RTU runs for 5 minutes to allow for system stabilization after startup.

High CO2 - The RTU Open generates this alarm when the space CO2 level exceeds the Alarm Configuration > Occupied High CO2 Alarm Limit setpoint for 1-minute. This alarm will be inhibited until the RTU has been

running for 2-minutes to allow for system stabilization after startup.

Supply Fan Runtime - The RTU Open generates a this alarm when the accumulated runtime exceeds the Unit Configuration > Supply Fan Service Alarm Timer value (when not set to 0). This alarm is most commonly

used to indicate an equipment maintenance interval is due. The supply fan runtime accumulator may be reset by setting the acknowledging each selection by clicking the

Maintenance > Reset Supply Fan Runtime Alarm to Clear, and then back to Run –

OK button when it appears. Setting Unit Configuration > Supply

Fan Service Timer value to 0 disables the supply fan runtime alarm function.

Compressor 1 Runtime - The RTU Open generates this alarm when the accumulated runtime exceeds the Unit Configuration > Compressor 1 Service Alarm Timer value (when not set to 0). This alarm is most

commonly used to indicate an equipment maintenance interval is due. The accumulator may be reset by setting the

Run – acknowledging each selection by clicking the OK button when it appears. Setting Unit

back to

Maintenance > Reset Comp 1 Runtime Alarm to Clear, and then

Compressor 1 Runtime

Configuration > Compressor 1 Service Timer value to 0 disables the Compressor 1 Runtime alarm function.

Compressor 2 Runtime - The RTU Open generates this alarm when the accumulated runtime exceeds the Unit Configuration > Compressor 2 Service Alarm Timer value (when not set to 0). This alarm is most

commonly used to indicate an equipment maintenance interval is due. The Compressor 2 runtime accumulator may be reset by setting the back to

Run – acknowledging each selection by clicking the OK button when it appears. Setting Unit

Maintenance > Reset Comp 2 Runtime Alarm to Clear, and then

Configuration > Compressor 2 Service Timer value to 0 disables the Compressor 2 runtime alarm function.

Note that this function is unavailable if the

Service Configuration > Compressor States value is not set to Two

Stages.

Filter - The RTU Open generates this alarm when the accumulated runtime exceeds the Unit Configuration > Filter Service Alarm Timer value (when not set to 0). This alarm is most commonly used to indicate a filter

replacement is due. Reset the filter service runtime accumulator by setting the

Maintenance > Reset Filter Runtime Alarm to On, back to Off, and clicking the OK button after each setting. Setting Unit Configuration > Filter Service Alarm Timer value to 0 disables the filter service alarm function.

Airside Linkage Alarm - An RTU Open may act as an air source in a zoned system. Carrier systems utilize a

function called Linkage™ to pass data between a master zone and its air source via an MS/TP network connection. When the RTU Open is part of a linked system, it will indicate an airside linkage alarm if it loses communications with its linkage master or if it receives invalid data.

52 RTU Open

Linkage

The RTU Open may serve as an air source to an Open Variable Volume Terminal (VVT) system. When the RTU Open is part of a VVT system and the controllers are wired together to form a network, the controllers may use a method of communication known as Linkage™. Linkage is a method by which an air source and its subordinate zone terminals exchange data to form a coordinated HVAC system. The system's air source controller, zone controllers, and bypass controller are linked so that their data exchange can be managed by one zone controller configured as the VVT Master.

The VVT Master gathers the following information from the slave zone controllers:

• occupancy status

• setpoints

• zone temperature

• relative humidity

• CO

level

• damper position

• optimal start data

The VVT Master performs mathematical calculations and algorithms on the data and then sends the composite information to the air source. The VVT Master receives information from the air source such as mode, supply air temperature, and outside air temperature, and passes that information to all linked controllers.

NOTE The following paragraphs describe the interaction between the air source (RTU Open) and its subordinate zones. Additional information regarding Open Zoned Systems may be found in the VVT Zone and VVT Bypass Controller Installation Guides.

The VVT Master determines system operation by prioritizing heating and cooling requirements from all the zones based on their occupancy and demand. The VVT Master scans the system continuously to determine if any zones are occupied. Occupied zones are a higher priority than unoccupied zones. The VVT Master evaluates all the occupied zones' heating or cooling demands and sends a request to the air source (RTU Open) for:

• Cooling, if the number of occupied zones with cooling demands exceeds the number of occupied zones

with heating demands, and the demand is greater than or equal to the number of configured

Callers

Linkage

• Heating, if the number of occupied zones with a heating demand exceeds or is equal to the number of

Linkage Callers

If no zones are occupied or no occupied zones require heating or cooling, the VVT Master performs the evaluation described above for the unoccupied zones.

The VVT Master then gathers the following information and sends it to the air source (RTU Open):

• The system mode

• The setpoints and zone temperature from the zone with the greatest demand for the requested air

source mode (heating or cooling). (This zone is called the reference zone.)

• The system occupancy status

• Most open damper position from any zone

• RH and CO2 values (if applicable)

The air source responds by sending the air source mode, supply air temperature, and outside air temperature. The air source verifies the mode by comparing its supply air temperature to the space temperature received through Linkage. See the air source documentation for operation and parameters used to verify its mode. This verification allows the VVT system to determine if the desired air source mode is actually being provided. For example, if the VVT Master sends a request for heating and the air source does not have heat or it’s heat has failed, the air source's actual mode indicates that and it's current mode is sent to the zones so that they can control accordingly.

RTU Open 53

Sequence of Operation

The system remains in that mode until all zones of that demand are satisfied or until a fixed 30 minute mode reselect timer causes a forced re-evaluation of the system. If there is no demand for the opposite mode, the reselect timer starts again and the current mode continues until all zones are satisfied or until the reselect timer expires, repeating the process. If there is a demand for the opposite mode, the VVT Master sends the reference zone's space temperature and setpoints to the air source and restarts the reselect timer. The air source re-evaluates its demand based on the new information and goes to the Vent mode until the new mode can be verified as described above. The amount of time this takes is determined by the air source’s operating parameters.

The VVT Master continuously evaluates the system and updates the air source with the most current system demand. Based on the evaluation, the reference zone can change from one zone to another. The evaluation process continues until there is no demand from any zone or the 30 minute timer causes a re-evaluation of the system conditions.

If no heating or cooling is required or the current air source mode is satisfied, the VVT Master calculates the weighted average of the occupied and unoccupied heating and cooling setpoints. It also calculates a zone temperature that is midway between the setpoints (occupied or unoccupied based on the system’s current occupancy status). This information, plus the occupancy status, is sent to the air source so that its current mode is disabled and the unit ceases heating or cooling operation. If the system is occupied, the air source fan and OA damper, if applicable, operate to maintain proper ventilation.

Linkage Air Source Modes

In a linked system, the air source determines its operating mode and qualifies that mode based on its own Supply Air Temperature (SAT). The following modes can be sent by the air source depending on its configuration:

• Off – Air source fan is off

• Fan Only – Air source fan is on and providing ventilation (neutral SAT) without heating or cooling

• Economizer Cooling – Air source fan is on and providing cooling, using economizer only

• Cooling – Air source fan is on and cooling is provided by economizer and mechanical cooling

• Heating – Air source fan is on and heating is provided (gas or electric)

• Dehumidification – Air source fan is on and Humidi-MiZer™ is active

• Test – The RTU Open Service Test mode is active

• Shutdown – Air source fan is off due to Safety Chain, Fire Shutdown, or invalid SAT sensor

• Unocc Free Cooling – Air source fan is on, with the economizer providing cooling while unoccupied

54 RTU Open

If this LED is on...

Status is...

Power

DO#

If Run LED shows...

And Error LED shows...

Status is..

Run

Troubleshooting

If you have problems mounting, wiring, or addressing the RTU Open, contact Carrier Control Systems Support.

Serial number

If you need the RTU Open's serial number when troubleshooting, the number is on:

• a sticker on the back of the main controller board

• a Module Status report (modstat) from your user interface

LED's

The LED's on the RTU Open show the status of certain functions.

The RTU Open has power

The RTU Open is receiving data from the network segment

The RTU Open is transmitting data over the network segment

The binary output is active

The

Run and Error LED's indicate controller and network status.

2 flashes per second

2 flashes per second 2 flashes,

2 flashes per second 3 flashes, then off The controller has just been

2 flashes per second On Exec halted after frequent system

5 flashes per second Off Firmware transfer in progress,

Off Normal

Five minute auto-restart delay

alternating with

after system error LED

formatted

errors or control programs halted

Boot is running

RTU Open 55

7 flashes per second 7 flashes per second,

alternating with

Ten second recovery period after brownout LED

Troubleshooting

If Run LED shows...

And Error LED shows...

Status is..

Run

14 flashes per second

On On Failure. Try the following solutions:

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

14 flashes per second, alternating with

Replacing the RTU Open's battery

Brownout

LED

• Turn the RTU Open off, then

on.

• Format the RTU Open.*

• Download memory to the RTU

Open.

• Replace the RTU Open.

The RTU Open's 10-year Lithium CR2032 battery provides a minimum of 10,000 hours of data retention during power outages.

CAUTION Power must be ON to the RTU Open when replacing the battery, or your date, time, and trend data will be lost.

1 Remove the battery from the controller, making note of the battery's polarity. 2 Insert the new battery, matching the battery's polarity with the polarity indicated on the RTU Open.

56 RTU Open

Compliance

FCC Compliance

This equipment has been tested and found to comply with the limits for a Class A digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instruction manual, may cause harmful interference to radio communications. Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be required to correct the interference at his own expense.

CAUTION Changes or modifications not expressly approved by the responsible party for compliance could void the user’s authority to operate the equipment.

CE Compliance

WARNING This is a Class A product. In a domestic environment, this product may cause radio interference in

which case the user may be required to take adequate measures.

BACnet Compliance

BACnet® is a registered trademark of ASHRAE. ASHRAE does not endorse, approve or test products for compliance with ASHRAE standards. Compliance of listed products to requirements of ASHRAE Standard 135 is the responsibility of the BACnet manufacturers Association (BMA). BTL® is a registered trademark of the BMA.

RTU Open 57

Appendix A: RTU Open Points/Properties

Properties > Equipment > Status HOME > STATUS

Point Name/Description

Range

System Mode

Operating Mode

Supply Fan Status

Fan Status

Space Temperature - Prime Variable Supply Air Temperature

Outdoor Air Temperature

Space Relative Humidity

Configuration > Unit

Configuration

Input 1

Function

Space RH Sensor

Indoor Air CO2

Configuration >Unit

Configuration > Input 1

Function

IAQ Sensor

Outdoor Air CO2

Configuration >Unit

Configuration >Input 1

Function

OAQ Sensor

Economizer Output

Appendix A: RTU Open Points/Properties

Status

Navigation: i-Vu / Field Assistant:

BACview:

– The current fan status if an input is configured for

control.

R: – The controller's current operating status. Disabled

Test Run

R: – The controller's current operating mode. Off

Fan Only Economizer Cooling Heating Dehumidification Test Shutdown Unocc Free Cooling (NTFC)

R: . Off/Running

R: – The space temperature value currently used for

-56 to 245°F

R: – The current supply air temperature. -56 to 245°F

R: – The outdoor air temperature value used for control. -56 to 245°F

– The current space relative humidity if

– The current indoor air CO2 concentration if the

damper (if equipped).

58 RTU Open

(or 2)

– The current outdoor air CO2 concentration if the

(or 2)

is set to

R: . 0 to 100%rh

R: . 0 to 5000ppm

R: – The current economizer output with respect to the outdoor air

0 to 100% Open

Properties > Equipment > Configuration > Unit Configuration HOME > CONFIG

UNIT

Point Name/Description

Default/Range

Fan Mode

Auto Continuous

Always On

Unit Start Delay

Fan Off Delay

Minimum Cooling SAT

Maximum Heating SAT

Vent Dmpr Pos / DCV Min Pos

DCV Max Vent Damper Pos

Supply Fan Service Alarm Timer

Compressor 1 Service Alarm Timer

Compressor 2 Service Alarm Timer

Filter Service Alarm Timer Filter Alarm

Pushbutton Override

Cooling Lockout Temp

Economizer High OAT Lockout

Unit Configuration

Navigation: i-Vu / Field Assistant:

BACview:

– The supply fan's operating mode.

Options:

- The fan cycles on/off in conjunction with heating or cooling.

- The fan runs continuously during occupancy & intermittently during

unoccupied periods with heating or cooling.

- The fan runs continuously regardless of occupancy or calls for heating and

cooling.

start command.

supply air temperature does not drop below this value.

supply air temperature does not rise above this value.

during occupied periods.

DCV is active.

Continuous

Auto Continuous Always On

D: – The amount of time the controller delays starting up after receiving a

5 sec

0 to 30 sec

D: – How long the supply fan runs after receiving a valid stop command.

90 sec

0 to 180 sec

D: – In cooling mode, the cooling outputs are controlled so that the

50°F

45 to 75°F

D: – In heating mode, the heating outputs are controlled so the

120°F

85 to 150°F

D: – The minimum outdoor air damper position maintained

50% Open

0 to 100% Open

D: – The maximum outdoor air damper position allowed while

50% Open

10 to 60% Open

supply fan run hours exceed this value. Set to 0 to disable.

the compressor 1 run hours exceed this value. Set to 0 to disable.

the compressor 2 run hours exceed this value. Set to 0 to disable.

– The amount of time the fan will run before generating a

. Set to 0 to disable the alarm and reset accumulated fan hours.

space temperature sensor.

cooling is inhibited.

RTU Open 59

D: – A Supply Fan Runtime alarm is generated when the

600 hr

0 to 9999 hr

D: – A Compressor 1 Runtime alarm is generated when

0 hr

0 to 9999 hr

D: – A Compressor 2 Runtime alarm is generated when

0 hr

0 to 9999 hr

600 hr

0 to 9999 hr

D: – Enables or disables the use of a pushbutton override from a local

Enable

Disable/Enable

D: – The outdoor air temperature at which cooling is inhibited.

45°F

0 to 80°F

D: – The outdoor air temperature at which economizer

75°F

55 to 80°F

Appendix A: RTU Open Points/Properties

Point Name/Description

Default/Range

HP Rev Cycle Lockout Temp

Heating Lockout Temperature

Unocc Free Cool Enable

Occupancy Source

Always Occupied BACnet Schedule BAS On/Off Remote Occ Input

Input Configuration

Input 1 Function

Input 2 Function

Input 3 Function

Input 3 Switch Configuration

No Function Compressor Safety Fan Status Filter Status Remote Occupancy Door Contact

Input 3 Switch Configuration

Input 5 Function

Input 5 Switch Configuration

No Function Fire Shutdown Fan Status Filter Status Remote Occupancy Door Contact

Input 5 Switch Configuration

heating is locked out. Requires that the unit is configured as a Heat Pump.

inhibited.

unoccupied free cooling (NTFC).

- The method that the controller uses to determine occupancy.

Options:

= Controller operates continuously as occupied.

= Controller follows a schedule set up in i-Vu or Field Assistant.

= Occupancy is set over the network by another device or a third party BAS.

=Occupancy is set by a remote contact.

– The usage of Input 3. You must also set

Options:

– The input is not used.

– Safety device status.

– Proves supply fan operation.

– Indicates a dirty filter.

– Sets occupancy using a hardware contact.

D: – The outdoor air temperature at which reverse cycle

-3°F

-20 to 30°F

D: – The outdoor air temperature at which heating is

65°F

35 to 150°F

D: – Enable to allow the unit to use economizer to provide

Disable

Disable/Enable

Always Occupied

Always Occupied BACnet Schedule BAS On/Off Remote Occ Input

D: – The type of sensor (4-20 mA) connected to terminals J4 – 4, 5, & 6.

No Sensor

No Sensor IAQ Sensor OAQ Sensor Space RH Sensor

D: – The type of sensor (4-20 mA) connected to terminals J4 – 1, 2, & 3.

No Sensor

No Sensor IAQ Sensor OAQ Sensor Space RH Sensor

Compressor Safety

No Function Compressor Safety Fan Status Filter Status Remote Occupancy Door Contact

terminated at Input

Options:

terminated at Input

60 RTU Open

– The usage of Input 5. You must also set

– The input is not used.

– Fire Safety device status. Inhibits operation when tripped.

– Proves supply fan operation.

– Indicates a dirty filter.

– Sets occupancy using a hardware contact.

D: – The normal (de-energized) state for the set of contacts

NO/NC (normally open/normally closed)

Fire Shutdown

No Function Fire Shutdown Fan Status Filter Status Remote Occupancy Door Contact

D: – The normal (de-energized) state for the set of contacts

NO/NC (normally open/normally closed)

Point Name/Description

Default/Range

Input 8 Function

Input 8 Switch Configuration

No Function Enthalpy Switch Fan Status Filter Status Remote Occupancy Door Contact

Input 8 Switch Configuration

Input 9 Function

Input 9 Switch Configuration

No Function Humidistat Fan Status Filter Status Remote Occupancy Door Contact

Input 9 Switch Configuration

Space sensor type

T5x Override Duration

Sensor Calibration

Space Temp Calibration

Supply Air Temp Calibration

Outside Air Temp Calibration

– The usage of Input 8. You must also set

Options:

– The input is not used.

– Indicates enthalpy status (high or low).

– Proves supply fan operation.

– Indicates a dirty filter.

– Sets occupancy using a hardware contact.

terminated at Input

– The usage of Input 9. You must also set

Options:

– The input is not used.

– Indicates high humidity condition.

– Proves supply fan operation.

– Indicates a dirty filter.

– Sets occupancy using a hardware contact.

terminated at Input

– Sets occupancy using a hardware contact.

Enthalpy Switch

No Function Enthalpy Switch Fan Status Filter Status Remote Occupancy Door Contact

D: – The normal (de-energized) state for the set of contacts

NO/NC (normally open/normally closed)

Humidistat

No Function Humidistat Fan Status Filter Status Remote Occupancy Door Contact

D: – The normal (de-energized) state for the set of contacts

NO/NC (normally open/normally closed)

D: - The type of local space temperature sensor.

T55

T55 T56 (Use for T59) SPT Sensor None

that the controller runs in the occupied mode when a user presses the sensor's override button for 1 to 10 seconds.

sensor to be adjusted to match a calibrated standard measuring the temperature in the same location.

temperature sensor to be adjusted to match a calibrated standard measuring the temperature in the same location.

Setpoints

RTU Open 61

1 hr

D: – If using a T55, T56, or T59 sensor, this is the amount of time

0 to 24 hours

D: – A calibration offset value to allow the local space temperature

D: – A calibration offset value to allow the supply air

D: – A calibration offset value to allow the outside air

0°F

-9.9 to 10°F

0°F

-9.9 to 10°F

0°F

-9.9 to 10°F

Appendix A: RTU Open Points/Properties

i-Vu / Field Assistant:

Navigation:

Properties > Equipment > Configuration > Setpoints HOME > CONFIG > SETPOINT

Heating

Cooling

Occupied Setpoints

Default

Demand Level

Point Name/Description

Occupied

1 2 3

Occupied Heating

Occupied Cooling

Occupied Heating 1

Occupied Heating

Occupied Heating 1

Occupied Heating

Occupied Heating 2

Occupied Heating 1

BACview:

Select a color band on the setpoint graph to see the current setpoints in the descriptions below.

and

fields. See setpoint

The occupied setpoints described below are the setpoints under normal operating conditions. The Demand Level 1–3 setpoints apply if demand limiting is used.

Demand limiting is a cost-saving strategy to reduce energy consumption. The strategy expands the occupied heating and cooling setpoints when the system reaches one of 3 levels of consumption. With the expanded setpoints, the equipment works less, thereby saving energy. By default, Demand Level 1 expands the occupied heating and cooling setpoints by 1°F, Demand Level 2 by 2°F, and Demand Level 3 by 4°F. If the occupied heating or cooling setpoints change, the (effective) demand level setpoints automatically change by the same amount. See Sequence of Operation 42 (page ) for more information.

Range: -40 to 245°F

The heating setpoint the controller maintains while in occupied mode.

The cooling setpoint the controller maintains while in occupied mode.

– Light Blue The space temperature must be less than the VVT Master to consider the zone a heating caller in a linked system. In a singlezone application, the heating requirement begins as soon as the space temperature falls below the

value be set no less than 0.5°F below the setpoint.

– Dark Blue The space temperature must be less than the generate a low space temperature alarm. We recommend that this value be set no less than 0.5°F below the

62 RTU Open

setpoint for the

setpoint. We recommend that the

setpoint.

setpoint to

70°F – Green

74°F – Green

69°F

68°F

69°F 68°F 66°F

75°F 76°F 78°F

68°F 67°F 65°F

67°F 66°F 64°F

Default

Demand Level

Point Name/Description

Occupied

1 2 3

Occupied Cooling 1

Occupied Cooling

Occupied Cooling 1

Occupied Cooling

Occupied Cooling 2

Occupied Cooling 1

Unoccupied Setpoints

Point Name/Description

Default/Range

Unoccupied Heating

Unoccupied Cooling

Unoccupied Heating 1

application, the unoccupied heating requirement begins as soon as the space temperature falls

Unoccupied Heating

Unoccupied Heating 1

Unoccupied Heating

Unoccupied Heating 2

Unoccupied Heating 1

Unoccupied Cooling 1

Unoccupied Cooling

Unoccupied Cooling 1

Unoccupied Cooling

Unoccupied Cooling 2

Unoccupied Cooling 1

Range: -40 to 245°F

– Yellow The space temperature must be greater than the the VVT Master to consider the zone a cooling caller in a linked system. In a singlezone application, the cooling requirement begins as soon as the space temperature exceeds the

value be set no less than 0.5°F above the setpoint.

– Orange The space temperature must be greater than the generate a high space temperature alarm. We recommend that this value be set no less than 0.5°F above the

setpoint. We recommend that the

setpoint.

setpoint for

setpoint to

75°F

76°F

The heating setpoint the controller maintains while in unoccupied mode.

The cooling setpoint the controller maintains while in unoccupied mode.

– Light Blue The space temperature must be less than the Master to consider the zone an unoccupied heating caller in a linked system. In a single-zone

setpoint for the VVT

76°F 77°F 79°F

78°F 78°F 81°F

D: – Gray

55°F

45 to 100°F

D: – Gray

90°F

-40 to 245°F

54°F

-40 to 245°F

below the be set no less than 0.5°F below the

– Dark Blue The space temperature must be less than the unoccupied low space temperature alarm. We recommend that this value be set no less than

0.5°F below the

– Yellow The space temperature must be greater than the Master to consider the zone an unoccupied cooling caller in a linked system. In a single-zone application, the unoccupied cooling requirement begins as soon as the space temperature exceeds the be set no less than 0.5°F above the

– Orange The space temperature must be greater than the unoccupied high space temperature alarm. We recommend that this value be set no less than

0.5°F above the

setpoint. We recommend that the

setpoint.

setpoint to generate an

setpoint.

setpoint for the VVT

setpoint. We recommend that the

setpoint.

setpoint to generate an

setpoint.

RTU Open 63

value

52°F

-40 to 245°F

91°F

-40 to 245°F

93°F

-40 to 245°F

Appendix A: RTU Open Points/Properties

Point Name/Description

Default/Range

Heating Capacity

Heating Design Temp

Cooling Capacity

Cooling Design Temp

Hysteresis

Time

Temp

Occupied heating setpoint: 70°

75.5°

70.5°

Occupied cooling setpoint: 76°

.5° hysteresis

Effective Setpoints

changes when the heating system runs at full capacity to maintain designed occupied heating setpoint.

system must run constantly to maintain comfort. This information is available in ASHRAE publications and most design references.

changes when cooling system runs at full capacity to maintain designed occupied cooling setpoint.

system must run constantly to maintain comfort. This information is available in ASHRAE publications and most design references.

– The desired difference between the temperature at which the zone color changes as the zone temperature departs from the acceptable range between the heating and cooling setpoints (green) into the Cooling 1 (yellow) or Heating 1 (light blue) and the temperature at which the zone color changes back to the acceptable range between the heating and cooling setpoints.

For example, the following graph shows the zone color that results as the zone temperature departs from and returns to the acceptable range in a zone with the following settings:

• Color Change Hysteresis = .5° (applies as the temperature returns to the acceptable

range)

• Occupied cooling setpoint = 76°

• Occupied heating setpoint = 70°

5°F/hr

D: – Used for Optimal Start, this is the rate at which the zone temperature

0 to 120°F/hr

0°F

D: – The geographically-based outdoor air temperature at which the heating

-100 to 150°F

5°F/hr

D: – Used for Optimal Start, this is the rate at which the zone temperature

0 to 140°F/hr

100°F

D: – The geographically-based outdoor air temperature at which the cooling

-100 to 150°F

0.5°F

0 to 120°F

The Effective Setpoints graph shows the current occupied or unoccupied setpoints. If occupied, these values are the current programmed setpoints plus the offset of any setpoint adjustment that may be in affect. If unoccupied, the values are the programmed unoccupied setpoints.

64 RTU Open

Point Name/Description

Heating –

Heating

Default/Range

Cooling –

Cooling

Optimal Start

Occ Relative Humidity Setpoint

Unocc Relative Humidity Setpoint

DCV Max Ctrl Setpoint

Power Exhaust Setpoint

Configuration >Service Configuration

Economizer Exists

Yes

Configuration >Service Configuration > Continuous Occupied Exhaust

Navigation:

Properties > Equipment > Configuration

Alarm Configuration

HOME > CONFIG > ALARMS

Point Name/Description

Default/Range Space Temperature Alarm

Occupied Alarm Hysteresis

Alarm Delay (min/deg) Unoccupied Low SPT Alarm Limit

Space Temperature Alarm

(Occupied or Unoccupied, depending on mode) The current programmed

setpoint adjusted by any offset that may be in effect.

(Occupied or Unoccupied, depending on mode) The current programmed

setpoint adjusted by any offset that may be in effect.

begin to adjust the effective setpoints to achieve the occupied setpoints by the time scheduled occupancy begins. Enter 0 to disable Optimal Start.

occupancy that will energize BO - 6 (Humidi-MiZer™).

unoccupied time period that starts the unit and energizes BO - 6 (Humidi-MiZer™).

- The outside air damper position at which the controller energizes the

Power Exhaust relay.

, and

must be set to must be set to

R: 0 to 120°F

0 to 120°F

4 hr

D: – The earliest time, prior to occupancy, at which the Optimal Start function may

0 to 4 hr

D: – The percentage of relative humidity in the space during

60%rh

0 to Unoccupied RH Control Setpoint

D: – The percentage of relative humidity in the space during the

95%

30 to 100%

D: – The design difference between indoor and outdoor CO2 levels.

650ppm

0 to 9999 ppm

50% Open

20 to 90% Open

Alarm Configuration

i-Vu / Field Assistant: BACview:

setpoint and subtracted from the occupied low effective setpoint to establish the occupied high and low limits that the space temperature must exceed before an occupied SPT alarm is generated. The alarm returns to normal when the space temperature drops below the high effective setpoint or rises above the low effective setpoint.

temperature alarm is generated when the controller transitions to the occupied mode. The delay time equals this value multiplied by the difference between the sensor temperature and occupied alarm setpoint plus 15 minutes.

below to generate a fixed hysteresis of 1° F for return to normal.

RTU Open 65

–The value that the space temperature must drop

in the unoccupied mode. There is a

3°F

D: – This value is added to the occupied high effective

0 to 20°F

10 minutes

D: – Determines the amount of delay before an occupied space

0 to 60 minutes

45°F

-60 to 250°F

Appendix A: RTU Open Points/Properties

Point Name/Description

Default/Range

Unoccupied High SPT Alarm Limit

Space Temperature Alarm

Supply Air Temperature Alarm

Low SAT Alarm Limit

Supply Air Temp Alarm

High SAT Alarm Limit

Supply Air Temp Alarm

Space Humidity Alarm

Low Space Humidity Alarm Limit

Configuration >Unit Configuration >Input 1

Function

Space RH Sensor

High Space Humidity Alarm Limit

Configuration >Unit Configuration >Input 1

Function

Space RH Sensor

IAQ/Ventilation Alarm

Occupied High CO2 Alarm Limit

IAQ Alarm

Configuration >Unit

Configuration >Input 1

Function

IAQ Sensor

Navigation:

Properties > Equipment > Configuration > Service Configuration HOME > CONFIG > SERVICE

Point Name/Description

Default/Range

Unit Type

Heat/Cool HP O/B Ctrl

HP Y1/W1 Ctrl

– The value that the space temperature must exceed to generate a fixed hysteresis of 1° F for return to normal.

– The value that the supply air temperature must drop below to

generate a

. There is a fixed hysteresis of 1° F for return to

normal.

– The value that the supply air temperature must exceed to

generate a

. There is a fixed hysteresis of 1° F for return to

normal.

– The value that the relative humidity must drop below to generate a Low Space Humidity Alarm. Requires a space relative humidity transmitter and

– The value that the relative humidity must rise above to generate a High Space Humidity Alarm. Requires a space relative humidity transmitter and

in the unoccupied mode. There is a

(or 2)

set to

90°F

-60 to 250°F

45°F

-60 to 250°F

120°F

-60 to 250°F

30%

0 – 99 %

70%

0 – 99 %

– The value that the CO2 sensor must exceed to

generate an

in the occupied mode. There is a fixed hysteresis of 100ppm

for return to normal. Requires a space CO2 sensor and

(or 2)

set to

Service Configuration

i-Vu / Field Assistant: BACview:

– The type of equipment that the RTU Open is controlling.

Options:

– Standard rooftop air handling unit.

– Heat Pump application, uses reversing valve output to control heating

and cooling.

– Carrier Heat Pump application only.

1200ppm

0 to 9999 ppm

Heat/Cool

Heat/Cool HP O/B Ctrl HP Y1/W1 Ctrl

66 RTU Open

Point Name/Description

Default/Range

Compressor Stages Economizer Exists

Yes

Heat Type

Number Of Heat Stages

Continuous Occupied Exhaust Yes

Power Exhaust Setpoint.

Indoor CO2 Sensor Value @min (ma)

Indoor CO2 Sensor Value @max (ma)

Outdoor CO2 Sensor Value @min (ma)

Outdoor CO2 Sensor Value @max (ma)

System Space Temperature

System Cool Demand Level

System Heat Demand Level

System Outside Air Temperature

network readable when enabled. Requires that controller is equipped with an outdoor

Service Test

Disable

Fan Test

Disable

Service Test

Enable

Compressor 1 Test

Service

Test

Enable

– Set to

an economizer damper.

– Configures the exhaust fan control strategy (BO-8). If

, the power exhaust runs continuously in occupied mode and is off in unoccupied

mode. If

input at the appropriate input channel.

controller is using for control (if applicable).

, the power exhaust is controlled by the

D: – The number of mechanical cooling stages.

One Stage

One Stage Two Stages

D: to enable economizer control for units equipped with

No/Yes

D: – The type of heating that the unit has.

Electric

Electric/Gas

D: – The number of heat stages.

R: 2 1 /2 /0 (no heating)

No/Yes

D: – The CO2 value that corresponds to a 4mA

0ppm

0 to 9999 ppm

D: – The CO2 value that corresponds to a 20mA

2000 ppm

0 to 9999 ppm

D: – The CO2 value that corresponds to a 4 mA

0ppm

0 to 9999 ppm

D: – The CO2 value that corresponds to a 20 mA

2000 ppm

0 to 9999 ppm

D: – The network space temperature value that the

-999.00 °F

N/A

network.

air temperature sensor.

– Enable to stop automatic control so you can test the controller's

outputs. Automatically resets to

after 1 hour.

– Enable to test the controller's fan speeds. Sequences fan from low to high

speed and operates at each speed for 1 minute. Resets to

must be set to

– Enable to test the controller's compressor 1 output.

must be set to

RTU Open 67

when complete.

D: – The system cool demand level being received over the

0.00

0 - 3

D: – The system heat demand level being received over the

0.00

0 - 3

D: – Allows the outside air temperature value to be

-999.0°F

N/A

Disable

Disable/Enable

Disable

Disable/Enable

Disable

Disable/Enable

Appendix A: RTU Open Points/Properties

Point Name/Description

Default/Range

Compressor 2 Test

Service

Test

Enable

Heat 1 Test

Service Test

Enable

Heat 2 Test

Service Test

Enable

Reversing Valve Test

Service

Test

Enable

Dehumidification Test

Service

Test

Enable

Power Exhaust Test

Service Test

Enable

Economizer Test

Service Test

Enable

Analog Output 2 Test

Navigation:

Properties > Equipment > Maintenance HOME > MAINT

Point Name/Description

Default/Range

Unit

Occupancy Status

Space Temp Sensor –

Sensor Failure SPT Sensor T55/56 Network

Airside Linkage Locked Value

Safety Chain Feedback

must be set to

– Enable to test the controller's heat 1 output.

– Enable to test the controller's heat 2 output.

must be set to

– Set to a value between 0 and 100% to test the controller's

economizer output.

– Enable to test the controller's compressor 2 output.

must be set

– Enable to test the controller's reversing valve output.

– Enable to test the controller's humidimizer output.

– Enable to test the controller's exhaust fan output.

must be set to

Disable

Disable/Enable

Disable

Disable/Enable

Disable

Disable/Enable

Disable

Disable/Enable

Disable

Disable/Enable

Disable

Disable/Enable

0% Open

0 to 100% Open

D: – Analog Output 2 (0-10 Vdc) is currently unused.

0 to 100%

Maintenance

i-Vu / Field Assistant: BACview:

schedule, a local schedule, or a timed override.

Options:

– No valid space temperature or sensor status = failed.

– An SPT sensor is connected to the controller’s Rnet port.

– A T55, T56, or T59 sensor is connected to the controller’s J20 terminals.

– A network temperature sensor is bound to the controller’s space temperature

AV.

– The space temperature from a linked terminal.

–The controller’s space temperature input has been manually locked at a

value.

typically used for safety devices that immediately stop unit operation when tripped.

68 RTU Open

The source of the controlling space temperature value.

R: – The controller's occupancy status as determined by a network

Occupied/Unoccupied

Sensor Failure SPT Sensor T55/T56 Network Airside Linkage Locked Value

R: - Indicates a completed circuit from J1, 1 to J1, 9. This circuit is

Off/Run Enabled

Point Name/Description

Default/Range

Fire Shutdown

Shutdown

Compressor Safety Status

Trouble

Enthalpy Status

Humidistat Input Status

Reset Supply Fan Runtime Alarm

Clear

Supply Fan Runtime

Reset Comp 1 Runtime Alarm

Clear

Compressor 1 Runtime

Reset Comp 2 Runtime Alarm

Clear

Compressor 2 Runtime

Reset Filter Runtime Alarm

Filter Runtime

Occupancy

BAS On/Off

Inactive Occupied Unoccupied

Schedules

Pushbutton Override

Active

Override Time Remaining Runtime

Supply Fan Runtime

Reset Supply Fan Runtime Alarm

Compressor 1 Runtime

Reset Comp 1 Runtime Alarm

Compressor 2 Runtime

Reset Comp 2 Runtime Alarm

Filter Runtime

Reset Filter Runtime Alarm

–

tripped.

– Set to

– Determines the occupancy state of the controller and can be set over the

network by another device or third party BAS.

Options:

– Occupancy is determined by a configured schedule.

– The controller is always in the occupied mode.

– The controller is always in the unoccupied mode.

to reset

R: indicates that a fire shutdown is in effect. Run Enabled/

Shutdown

R: indicates that the compressor safety device has

Normal/Trouble

R: – The enthalpy status determined by an enthalpy switch. High/Low

R: – The humidity status determined by a humidistat. High/Low

D: to 0.

Run

Run/Clear

D: to 0.

Run

Run/Clear

D: to 0.

Run

Run/Clear

D: to 0.

Off

Off/On

Inactive

Inactive Occupied Unoccupied

R: – The controller's occupancy status based on the schedule. Occupied/Unoccupied

override the occupancy state.

energized since the runtime was last reset to 0 using

been energized since the runtime was last reset 0 using

been energized since the runtime was last reset using

runtime was last reset to 0 using

RTU Open 69

–

indicates if a user pushed the sensor's override button to

– The amount of time remaining in an override period. 0 to 240 minutes

– The total number of hours that the supply fan relay has been

– The total number of hours that the Compressor 1 relay has

– The total number of hours that the Compressor 2 relay has

– The total number of hours that the unit has been operating since the

Off/Active

R: . ___ hr

Appendix A: RTU Open Points/Properties

Navigation:

Properties > Equipment > Alarms HOME > ALARM

Point Name/Description

Range

Safety Chain

Fire Shutdown

Compressor Safety

Space Temp Sensor –

Supply Air Temp Sensor –

Outdoor Air Temp Sensor Alarm –

Space Relative Humidity Sensor –

IAQ Sensor –

OAQ Sensor –

Space Temperature –

Alarming Temperature Alarm Limit Exceeded

High Supply Air Temperature

High SAT

Alarm Limit

Low Supply Air Temperature

Low SAT

Alarm Limit

Setpoint Slider

Switch Configuration

Analog Input Configuration

High Space Relative Humidity

High

Space Humidity Alarm Limit

Low Space Relative Humidity

Low

Space Humidity Alarm Limit

High CO2

Occupied High CO2 Alarm Limit

Supply Fan Runtime

Supply Fan

Service Alarm Timer

Compressor 1 Runtime Compressor 1 Service Alarm Timer

Alarms

limit.

i-Vu / Field Assistant: BACview:

Indicates if the indoor air quality (CO

Indicates if the outdoor air quality (CO

) sensor fails.

R: – Indicates if the Safety Chain circuit trips. Normal/Alarm

R: – Indicates if the Fire Shutdown circuit trips. Normal/Alarm

R: – Indicates if the Compressor Safety circuit trips. Normal/Alarm

R: Indicates if the space temperature sensor fails. Normal/Alarm

R: Indicates if the supply air temperature sensor fails. Normal/Alarm

R: Indicates if the outdoor air temperature sensor fails. Normal/Alarm

R: Indicates if the space relative humidity sensor fails. Normal/Alarm

Normal/Alarm

R: Indicates if the space temperature sensor exceeds the high or low alarm

Normal/Alarm

R: – The value of the alarming space temperature sensor. The sensor's

range

R: – The alarm limit that the alarming space temperature sensor exceeded. -60 to 250°F

3, 5, 8, & 9 Functions.

& 2 Functions.

– Indicates if the indoor CO2 level rises above the

– Indicates if the supply fan runtime exceeds the value of the

– Indicates if the supply air temperature exceeds the

– Indicates if the supply air temperature falls below the

– Indicates if the space relative humidity exceeds the

– Indicates if the space relative humidity falls below the

– Indicates if the compressor 1 runtime exceeds the value of the

R: . Normal/Alarm

R: – Indicates if the T56 sensor's setpoint slider potentiometer fails. Normal/Alarm

R: – Indicates if a duplicate configuration exists for two or more binary Input

Normal/Alarm

R: – Indicates if a duplicate configuration exists at the analog Input 1

Normal/Alarm

R: . Normal/Alarm

70 RTU Open

Point Name/Description

Range

Compressor 2 Runtime Compressor 2 Service Alarm Timer

Filter

Service Alarm Timer

Airside Linkage Alarm

i-Vu / Field Assistant:

Navigation:

Properties > Equipment > Linkage Properties > Equipment

Linkage

Point Name/Description

Range

Airside Linkage Status

Active

Not

Active

Airside Linkage Status

Active

Occupancy Status Space Temperature Occupied Cooling Setpoint Occupied Heating Setpoint Unoccupied Cooling Setpoint Unoccupied Heating Setpoint Indoor Air CO2 Space Relative Humidity

– Indicates if the compressor 1 runtime exceeds the value of the

– Indicates a dirty filter condition when the filter runtime exceeds the value of the

or in response to a filter status switch binary input.

Linkage

BACview:

Linkage Collector – Allows access to the Collector's details.

– If

, the controller is a stand-alone device.

the VVT Master (as applicable):

, the controller is part of a linked system. If

, the following provide information received from

R: . Normal/Alarm

Clean/Dirty

R: – Indicates if Linkage fails in a zoned system using Linkage. Normal/Alarm

Active/Not Active

I/O Points

The values shown on the I/O Points Properties page are the raw values at the I/O objects and may not match values shown on status displays that are affected by control program logic.

i-Vu users logged in as Power User and above are able to edit various parameters associated with the input channels and the display names for all channels.

We strongly recommend that you leave these parameters at their defaults. The RTU Open is not a programmable controller. I/O can only be used for the purpose designed in the equipment control program. Modifying these parameters may result in unpredictable equipment control.

See Wiring inputs and outputs (page 12) for more information. This table lists each of the I/O Channels, their

RTU Open 71

functions, associated hardware, and terminal numbers.

Appendix A: RTU Open Points/Properties

i-Vu / Field Assistant:

Navigation:

Properties > I/O Points N/A

Point Name/Description

Space Temp input 1

input 2

input 6

input 7

input 10

input 11

slidepot voltage reading

input 3 input 4

input 5

input 8

input 9

Sensor Invalid ao 1

ao 2

relay 1

relay 2

relay 3

relay 4

relay 5

relay 6

relay 7

relay 8

BACview:

– The value of the Optional SPT (Rnet) sensor. Also allows i-Vu & Field Assistant users access to sensor

configuration. See Carrier Sensors Installation Guide

– Input Channel 1; 4 - 20 mA only. User-configurable for IAQ, OAQ, or Space RH.

– Input Channel 2; 4 - 20 mA only. User-configurable for IAQ, OAQ, or Space Relative Humidity.

– Input Channel 6; 10K Thermistor only. Supply Air Temperature.

– Input Channel 7; 10K Thermistor only. Outside Air Temperature.

– Input Channel 10; 10K Thermistor only. Space Temperature (T55, 56, 59).

– Input Channel 11; 100K Potentiometer only. Setpoint adjust (T56, 59).

– Input Channel 11; used to detect an open circuit (faulty Setpoint adjustment mechanism).

– Input Channel 3; Dry Contact only. User-configurable for No Function, Compressor Safety, Fan Status, Filter

Status, Remote Occupancy, or Door Contact.

– Input Channel 4; Dry Contact only. Safety Chain.

for additional details.

– Input Channel 5; Dry Contact only. User-configurable for No Function, Fire Shutdown, Fan Status, Filter

Status, Remote Occupancy, or Door Contact.

– Input Channel 8; Dry Contact only. User-configurable for No Function, Enthalpy, Fan Status, Filter Status,

Remote Occupancy, or Door Contact.

– Input Channel 9; Dry Contact only. User-configurable for No Function, Humidistat, Fan Status, Filter Status,

Remote Occupancy, or Door Contact.

– Reflects the status of the Space Temp (Rnet) input. On = Space Temp invalid,

Off = Space Temp valid.

– Analog Output Channel 1; jumper selectable.

– Analog Output Channel 2; 0 - 10 Vdc. Not Utilized.

– Binary Output 1; Fan (G) Output.

– Binary Output 2; Heat 2 (W2) Output.

– Binary Output 3; Heat 1 (W1) Output.

– Binary Output 4; Cool 2 (Y2) Output.

– Binary Output 5; Cool 1 (Y1) Output.

– Binary Output 6; Humidi-MiZer ™ Output.

– Binary Output 7; Reversing Valve Output.

72 RTU Open

– Binary Output 8; Power Exhaust Output.

Appendix B: Single Point Linkage and Device Address Binding

Single Point Linkage

The RTU Open receives data from other Open controllers when they are installed as part of an Open system. The data transfer may take the form of Single Point Linkage (SPL), which is automatic, or Device Address Binding, which you must configure.

Currently, the RTU Open implements Single Point Linkage for 3 variables: Refer to configuration section -

complete list - make list to system system configuration1.....might be different for RTU - might be unit config

• System Cool Demand Level

• System Heat Demand Level

• System Outside Air Temperature

Network Points for which SPL has been implemented are displayed in i-Vu and Field Assistant on the Properties page > Network Points tab.

The following example involves outside air temperature. System Heat & Cool Demand Level behaves similarly, except that their usage involves a specific application loaded on a Universal Controller Open. See UC Open Installation Guide for additional information. In either case, note that the BACnet type and instance numbers specified in the

Network variables for which SPL is used are easily identified on the Properties page > Network Points tab. The asterisk in the BACnet address invokes the SPL function. These addresses cause the controller to issue a BACnet “who has” command for this variable. The controller binds to the closest of the first five devices from which it receives a valid response.

Address field of these variables have been predefined.

RTU Open 73

Appendix B: Single Point Linkage and Device Address Binding

Device Address Binding

As described previously, Device Address Binding allows the RTU Open to receive data from other Open controllers when they are connected by a network. You must configure this method.

Currently, the RTU Open allows Device Address Binding (DAB) only for System Space Temperature.

Network Points on which DAB may be implemented are displayed in i-Vu and Field Assistant on the Properties page >

Network Points tab with an undefined BACnet address.

74 RTU Open

Index

BACnet compliance • 57 BACnet port • 11 BT485 • 10

Compliance • 57

Duct Air Temperature sensor • 22 Duct sensors

Duct Air Temperature sensor • 22 Supply Air Temperature sensor • 21

FCC compliance • 57 Field Assistant • 58

i-Vu • 58

Linkage • 73

Module Status report • 55 MS/TP network, wiring • 10

Points/Properties • 58

Airside Linkage Alarm • 70 Airside Linkage Status • 71 Alarm Delay (min/deg) • 65 Alarm Limit Exceeded • 70 Alarming Temperature • 70 Analog Input Configuration • 70 Analog Output 2 Test • 65 BAS On/Off • 68 Compressor 1 Runtime • 68 Compressor 1 Runtime alarm • 70 Compressor 1 Service Alarm Timer • 59 Compressor 1 Test • 66 Compressor 2 Runtime • 68 Compressor 2 Runtime alarm • 70 Compressor 2 Service Alarm Timer • 59 Compressor 2 Test • 66 Compressor Safety alarm • 70 Compressor Safety Status • 68 Compressor Stages • 40, 66 Continuous Occupied Exhaust • 40, 66 Cooling Capacity • 61 Cooling Design Temp • 61 Cooling Lockout Temp • 59 DCV Max Ctrl Setpoint • 39, 59

RTU Open 75

DCV Max Vent Damper Pos • 59 Dehumidification Test • 66 Economizer Exists • 40, 66 Economizer High OAT Lockout • 59 Economizer Output • 58 Economizer Test • 66 Enthalpy Status • 68 Fan Mode • 37, 59 Fan Off Delay • 59 Fan Test • 66 Filter Alarm • 70 Filter Runtime • 68 Filter Service Alarm Timer • 59 Fire Shutdown • 68 Fire Shutdown alarm • 70 Heat 1 Test • 66 Heat 2 Test • 66 Heat Type • 40, 66 Heating Capacity • 61 Heating Design Temp • 61 Heating Lockout Temperature • 59 High CO2 alarm • 70 High SAT Alarm Limit • 65 High Space Humidity Alarm Limit • 65 High Space Relative Humidity alarm • 70 High Supply Air Temperature alarm • 70 HP Rev Cycle Lockout Temmp • 59 Humidistat Input Status • 68 Hysteresis • 61 IAQ Sensor alarm • 70 Indoor Air CO2 • 58, 71 Indoor CO2 Sensor Value @max (ma) • 40, 66 Indoor CO2 Sensor Value @min (ma) • 40, 66 Input # Function • 37, 59 Input # Switch Configuration • 37, 59 LAT Airflow Increase • 58 Linkage Collector • 71 Low SAT Alarm Limit • 65 Low Space Humidity Alarm Limit • 65 Low Space Relative Humidity alarm • 70 Low Supply Air Temperature alarm • 70 Maximum Heating SAT • 59 Minimum Cooling SAT • 59 Number of Heat Stages • 40, 66 OAQ Sensor alarm • 70 OAT System Sensor • 66 Occ Relative Humidity Setpoint • 39, 61 Occupancy Source • 37, 59 Occupancy Status • 68, 71 Occupied Alarm Hysteresis • 65 Occupied Cooling • 39, 61 Occupied Cooling 1 • 61 Occupied Cooling 2 • 61 Occupied Cooling Setpoint • 71 Occupied Heating • 39, 61 Occupied Heating 1 • 61 Occupied Heating 2 • 61 Occupied Heating Setpoint • 71 Occupied High CO2 Alarm Limit • 65

Index

Operating Mode • 58 Optimal Start • 39, 61 Outdoor Air CO2 • 58 Outdoor Air Temp Sensor Alarm • 70 Outdoor Air Temperature • 58 Outdoor CO2 Sensor Value @max (ma) • 40, 66 Outdoor CO2 Sensor Value @min (ma) • 40, 66 Outside Air Temp Calibration • 59 Override Time Remaining • 68 Power Exhaust Setpoint • 39, 61 Power Exhaust Test • 66 Pushbutton Override • 59, 68 Reset Comp 1 Runtime Alarm • 68 Reset Comp 2 Runtime Alarm • 68 Reset Filter Runtime Alarm • 68 Reset Supply Fan Runtime Alarm • 68 Reversing Valve Test • 66 Safety Chain alarm • 70 Safety Chain Feedback • 68 Schedules • 68 Service Test • 66 Setpoint Slider • 70 Space Relative Humidity • 58, 71 Space Relative Humidity Sensor alarm • 70 Space sensor type • 37, 59 Space Temp Calibration • 59 Space Temp Sensor • 70 Space Temp Sensor Alarm • 70 Space Temperature • 71 Space Temperature - Prime Variable • 58 Space Temperature Alarm • 70 Supply Air Temp Calibration • 59 Supply Air Temp Sensor alarm • 70 Supply Air Temperature • 58 Supply Fan Runtime • 68 Supply Fan Runtime alarm • 70 Supply Fan Service Alarm Timer • 59 Supply Fan Status • 58 Switch Configuration • 70 System Cool Demand Level • 66 System Heat Demand Level • 66 System Mode • 58 System Outside Air Temperature • 66 System Space Temperature • 66 T5x Override Duration • 59 Unit Start Delay • 59 Unit Type • 40, 66 Unocc Free Cool Enable • 59 Unocc Relative Humidity Setpoint • 39, 61 Unoccupied Cooling • 39, 61 Unoccupied Cooling 1 • 61 Unoccupied Cooling 2 • 61 Unoccupied Cooling Setpoint • 71 Unoccupied Heating • 39, 61 Unoccupied Heating 1 • 61 Unoccupied Heating 2 • 61 Unoccupied Heating Setpoint • 71 Unoccupied High SPT Alarm Limit • 65 Unoccupied Low SPT Alarm Limit • 65 Vent Dmpr Pos / DCV Min Pos • 59

Rnet wiring specifications • 20

Serial number • 55 SPT sensors • 20 Supply Air Temperature sensor • 21

temperature sensors

Duct Air Temperature sensor • 22 SPT sensors • 20 Supply Air Temperature sensor • 21

Troubleshooting • 55

Wiring specifications

Network • 11 Rnet • 20

Rnet • 20

76 RTU Open

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

Carrier 1-808-427-01 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Introduction

What is the RTU Open controller?

Specifications

Safety considerations

Installation

Field-supplied hardware

To mount the RTU Open

To wire the controller for power

Using the rooftop equipment control power transformer

Using an auxiliary control power transformer

To set the RTU Open's address

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

Wiring the RTU Open to the MS/TP network

Wiring specifications

To wire the controller to the network

Wiring inputs and outputs

Input wiring specifications

Inputs

Binary outputs

Analog output

To wire inputs and outputs

Wiring sensors to inputs

Field-supplied sensor hardware

Wiring an SPT sensor

Rnet wiring specifications

To wire the SPT sensor to the controller

Wiring a Supply Air Temperature sensor

Wiring specifications

To wire the SAT sensor to the controller

Wiring a Duct Air Temperature sensor

Wiring specifications

To wire a duct sensor to the controller

Wiring an Outdoor Air Temperature sensor

Wiring specifications

To wire an OAT sensor to the controller

Wiring a CO2 sensor

Wiring specifications

To wire the CO2 sensor to the controller

Wiring an Outdoor Air Quality sensor

Wiring specifications

To wire the OAQ sensor to the controller

Wiring a Relative Humidity sensor

Wiring specifications

To wire the RH sensor to the controller

Wiring a Humidistat

Wiring specifications

To wire a humidistat to the controller

Wiring an enthalpy switch

Wiring specifications

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

To wire an enthalpy switch (differential) to the controller

Wiring a status switch

Wiring specifications

To wire a status switch to the controller

Wiring a compressor safety

Wiring specifications

To wire a compressor safety input to the controller

Wiring an occupancy switch or door contact

Wiring specifications

To wire an occupancy switch or door contact

Start-up

Service Test

Configuring the RTU Open's properties

Unit Configuration properties

Setpoint properties

Service Configuration properties

Sequence of Operation

Occupancy

Supply fan

Cooling

Economizer

Power Exhaust

Unoccupied Free Cooling

Optimal Start

Enthalpy control

Indoor Air CO2