Johnson Controls CD-Wxx-00-0 Series Catalog Page

CD-Wxx-00-0 Series Wall Mount CO2 Transmitter

Product Bulletin

	CD-Wxx-00-0	Code No. LIT-216527
		Issued July 14, 2011
		Supersedes June 1, 2001
		Refer to the QuickLIT Web site for the most up-to-date version of this document.

Johnson Controls offers a full line of Carbon Dioxide (CO2) transmitters for measuring and transmitting CO2

levels, ranging from 0 to 2,000 parts per million (ppm), within Heating, Ventilating, and Air Conditioning (HVAC) CO2 applications. Specific HVAC CO2

applications include Demand Control Ventilation (DCV), fresh air and Indoor Air Quality (IAQ), and rooftop air handling Economizer controls systems.

These compact, wall mounted devices output 0 to 10 V (default), 0 to 20 mA, or 4 to 20 mA signals and feature analog temperature outputs, relay outputs, and/or a digital display as (optional) features. They are designed to work:

•in standalone mode

•connected to Metasys® system

•as part of any integrated Building Automation System (BAS)

These new CO2 transmitters are easy to install, offer a

full three year warranty, and require no maintenance or field calibration.

Table 1: Features and Benefits

Figure 1: Wall Mount CO2 Transmitter with Display

Features	Benefits
Energy Savings from DCV Strategies	Offer potential for 10 to 70% energy savings.
CARBOCAP® Single-Beam, Dual-Wavelength Design	Provides superior performance compared to other technologies.
CARBOCAP Silicon, Micro-machined Construction	Provides reliable CO2 measurement in room environments.
Calibration Reliability	Offers 5 years of reliable calibration.
Stable Infrared Reference	Compensates for light-source drift.

CD-Wxx-00-0 Series Wall Mount CO2 Transmitter Product Bulletin

1

Product Overview

This transmitter uses a completely new CO2 sensing

technology. The silicon based CARBOCAP® sensor provides stability and reliability.

The CARBOCAP sensor operates in accordance with the single beam, dual wavelength method. This patented sensor has unique reference measurement capabilities, offering excellent stability over both time and temperature. The monolithic Fabry-Perot Interferometer (FPI) chip uses the optical, mechanical, and electronic properties of silicon at the same time.

The transmitter is factory set to measure CO2 levels up

to 2,000 ppm. It requires a Class 2, 24 VDC/VAC power source and generates an output signal proportional to the CO2 level detected. One simple wire to a screw

terminal and a jumper on the Printed Circuit Board (PCB) combine to select the analog output signal from the following options:

•0 to 20 mA

•4 to 20 mA

•0 to 10 V (default)

IMPORTANT: The CD-Wxx-00-0 CO2 Transmitter

is intended to provide an input to equipment under normal operating conditions. Where failure or malfunction of the transmitter could lead to personal injury or property damage to the controlled equipment or other property, additional precautions must be designed into the control system. Incorporate and maintain other devices, such as supervisory or alarm systems or safety or limit controls, intended to warn of or protect against failure or malfunction of the transmitter.

Calibration

Johnson Controls® CO2 transmitters are calibrated using certified gases for the following:

•output signal (0 to 10 V) proportional to CO2 concentration (0 to 2,000 ppm)

•altitude range of 0 to 2,000 ft (0 to 600 m) above sea level without compensation

•relay output trigger point set for 1,000 ppm (in models featuring the optional relay output)

CARBOCAP Technology

Johnson Controls is licensed to integrate the new, silicon based CARBOCAP CO2 sensor into HVAC or

Building Automation Systems. This sensor has several advantages: high accuracy, excellent stability, negligible temperature dependence, and ease of installation.

The structure of the diffusion aspirated, single-beam dual-wavelength sensor is remarkably simple. It consists of an Infrared (IR) source, a sample cell, a tunable interference filter, and an IR detector. The tunable interference filter enables measurements at two wavelengths. As a result, references are measured accurately, without the typically broad tolerances inherent in dual-beam sensors.

Dust, water vapor, and most chemicals do not affect the measurement accuracy of the sensor. No special software compensation patches are required, and the device requires no maintenance.

Versatile Transmitter

Designed for use with a standard U.S. wallbox or mounting directly to a wallboard surface, the CO2

transmitter generates considerable savings in installation, operation, and maintenance with no recalibration costs. Johnson Controls includes a Drywall Spring-Clip Mounting Kit with each unit.

2 CD-Wxx-00-0 Series Wall Mount CO2 Transmitter Product Bulletin