Dwyer Instruments CDX Series Supplement

Bulletin AQ-CDX
The Series CDX Carbon Dioxide Transmitter is a low cost and high
performing CO2 sensor. On-Demand ventilation using CO2 sensors
prevents energy losses from over ventilation while maintaining indoor air
quality. The potential for the greatest energy saving occurs in areas
where occupancy varies over the duration of the day. The Series CDX
Transmitters utilize a proprietary logic algorithm to eliminate the need for
manual calibration in applications where the indoor CO2 level drops to
outside levels during unoccupied periods.
M UNTING
Push the tabs on the bottom of the housing to remove the cover. Mount
the back plate to the wall or junction box with the supplied screws and
make the necessary wire connections. Attach the cover to the back plate
by aligning the top clips and securing the bottom clips.
SELECTI N F V LTAGE UTPUT
Prior to wiring, verify that the voltage selection jumper is set to the
desired output type. For voltage output selection, the output can be 0 to
5 VDC or 0 to 10 VDC. Voltage (see below).
0 to 10 V Jumper Selected (left), 0 to 5 V Jumper Selected (right).
DWYER INSTRUMENTS, INC. Phone: [phone] www.dwyer-inst.com
P. . B X 373 • MICHIGAN CITY, INDIANA 46360, U.S.A. Fax: [phone] e-mail: [email protected]
SPECIFICATI NS
Range: 0 to 2000 PPM.
Accuracy: ±30 PPM or 3% of reading, whichever is higher. CO2
accuracy statement excludes standard gas used for calibration that has
an accuracy of 2% and there is a potential digital to analog error of up
to 1%.
Temperature Dependence: 0.2% FS per °C (± 0.11% per °F).
Stability: < 2% of FS over life of sensor (15 years).
Pressure Dependence: .135% of reading per mm of Hg.
Response Time: 5 s.
Warm Up Time: < 2 min (operational), 10 min (max. accuracy).
Temperature Limits:
Operating: 32 to 122°F (0 to 50°C);
Storage: -40 to 158°F (-40 to 70°C).
Humidity Limits: 0 to 95% relative humidity, non-condensing.
Power Requirements: 18 to 30 VAC RMS, 50/60 Hz, or 18 to 42
VDC, polarity protected.
Power Consumption: .7 W @ nominal voltage of 24 VAC RMS.
Sensor: Non-dispersive infrared (NDIR) absorption.
utput: Analog, 0 to 5 V or 0 to 10 V jumper selectable (100 Ω output
impedance), 4 to 20 mA (R maximum 500 Ω).
Housing: Flammability classification U 94 5VA.
Weight: European Housing: 5.44 oz (154 g); North American Housing:
6.24 oz (177 g).
Agency Approvals: CE, RoHS.
Specifications - Installation and perating Instructions
Series CDX Wall Mount Carbon Dioxide Transmitter
4-37/64
[116.33]
1-1/64
[25.65]
3-13/64
[81.28]
Ø5/32 x 4
[Ø3.87]
Ø5/32 x 3
[Ø3.87]
3-13/64
[81.28]
1-1/16
[27.18]
3-13/32
[86.36]

©Copyright 2013 Dwyer Instruments, Inc. Printed in U.S.A. 11/13 FR# R6-444152-00 Rev. 1
DWYER INSTRUMENTS, INC. Phone: [phone] www.dwyer-inst.com
P. . B X 373 • MICHIGAN CITY, INDIANA 46360, U.S.A. Fax: [phone] e-mail: [email protected]
WIRING C NFIGURATI NS
Figure 1: Current Wiring for 3-Wire System – AC Power
Figure 2: Voltage Wiring for 3-Wire System – AC Power
Figure 3: Current Wiring for 4-Wire System – AC Power
Figure 4: Voltage Wiring for 4-Wire System – AC Power
The Series CDX has two terminal pins that are connected inside the sensor
to a common/ground: pin #7 on the I/O terminal blocks and pin #2 on the
power block. Do NOT connect positive 24 VAC power line to pin #2 of the
terminal block.
P WER SUPPLY REQUIREMENTS
The sensor can be powered with either 18 to 30 VAC or 18 to 42 VDC,
while the DC power is polarity protected. AC power must be at a frequency
between 50 to 60 Hz.
CALIBRATI N
The Series CDX is factory set with the proprietary logic function activated.
The logic function allows the sensor to continuously re-calibrate itself when
the indoor concentrations drop to levels similar to outside conditions when
the building is unoccupied. The building must be unoccupied for a
minimum of 4 hours or more for this self calibration to be effective. The
logic allows the sensor to maintain its calibration over the life of the sensor.
ACCESS RY ENCL SURES
When mounting these products inside the ductwork, seal the hole around
the wires and leave the duct insulation in place to prevent condensation
which may damage the sensor.
Model 1508 Duct Mount Enclosure
The CDX units can be installed inside a Model 1508 Duct Mount Enclosure.
Model 1552 utside Air Measurement Enclosure
This NEMA-3R weatherproof enclosure includes thermostat and allows
installation of the sensor in environments with temperatures down to -40°F
(-40°C).
Duct Mount Enclosure (left), utside Air Enclosure (right)
MAINTENANCE/REPAIR
Upon final installation of the Series CDX, no routine maintenance is
required. The Series CDX is not field serviceable and should be returned if
repair is needed. Field repair should not be attempted and may void
warranty.
WARRANTY/RETURN
Refer to “Terms and Conditions of Sale” in our catalog and on our website.
Contact customer service to receive a Return Goods Authorization number
before shipping the product back for repair. Be sure to include a brief
description of the problem plus any additional application notes.
Before performing service or maintenance operations on the
systems, turn OFF main power switches to the unit. Electric
shock can cause personal injury. Please read and follow the wiring instructions
precisely because improper wiring my cause permanent damage to the product.
WARNING
The Series CDX is either a 3-wire or 4-wire type configuration,
powered by either AC or DC voltage. It is not a 2-wire or loop
device. Wiring the units as 2-wire or loop-powered devices will irreparably damage
the sensors and void the warranty.
CAUTI N
Recommended length of wire after being
stripped of insulation for terminal pin (left).