Carrier 11-808-427-01 Wiring a CO2 sensor

Installation

24 RTU Open

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 CO2 sensor can be wall-mounted or

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

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

Maximum length: 500 feet (152 meters)

To wire the CO2 sensor to the controll er

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.

Contents

Main Page Table of Contents Page Page Page What is the RTU Open controller? Introduction Page Specifications Safety considerations Field-supplied hardware Installation 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 J3 W1 J4 Inputs J5 Inputs J11 Outputs NOTE NOTE J20 Analog Inputs 10 and 11 are reserved for a 10k Ohm space temperature sensor with an Wiring sensors to inputs Field-supplied sensor hardware Wiring an SPT sensor Rnet wiring speci ficati ons To wire the SPT sensor to the controll er Wiring a Supply Air Temperature sensor Wiring specifications To wire the SAT sensor to the c ontroller 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 controll er Wiring an Outdoor Air Quality sensor Wiring specifications To wire the OAQ se nsor to the controller Wiring a Relative Humidity sensor Wiring specifications To wire the RH sensor to the controll er Wiring a Humidistat Wiring specifications To wire a humidis ta t to the controller Wiring an enthalpy switch Wiring specifications To wire an enthalpy sw itch (outdoor air) to the controller To wire an enthalpy sw itch (differential) to the controller Wiring a status switch To wire a status switch to the controller Wiring a compressor safety Wiring specifications To wire a compress or safety input to the c ontroller 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 Page Setpoint properties Service Configuration properties Page Occupancy Sequence of Operation Supply fan Cooling Economizer Power Exhaust Unoccupied Free Cooling Optimal Start To change Optimal Start settings: Enthalpy control Indoor Air CO2 Heating Heat Pump operation Dehumidification Demand Limit Door switch Remote occupancy Fire Shutdown Compressor Safety Fan Status Filter Status Alarms Page Page Linkage Linkage Air Source Modes Serial number Troubleshooting LED's Replacing the RTU Open's battery FCC Compliance Compliance CE Compliance BACnet Compliance Status Appendix A: RTU Open Points/Properties Unit Configuration Page Setpoints Page Page Page Alarm Configuration Service Configuration Page Maintenance Page Alarms Linkage I/O Points Page Single Point Linkage Appendix B: Single Point Linkage and Device Address Binding Device Address Binding B Index C D F I R S T W