Dwyer Instruments CDT Series Installation And Operating Instructions

Series CDT and CDTR Duct Mount Carbon Dioxide/
Temperature/Relative Humidity Transmitter
Specifications - Installation and Operating Instructions
Series CDT and CDTR Duct Mount Carbon Dioxide/ Temperature/Relative
Humidity Transmitters accurately monitor the CO
in schools, office buildings, and other indoor environments to help achieve LEED
certification. For increased sensor life, a single- beam dual-wavelength non-dispersive
infrared (NDIR) sensor is used to automatically correct the measurement in both
occupied and unoccupied buildings against aging effects. The single-beam dual-
wavelength sensor technology provides the highest level of accuracy, compared to
Automatic Baseline Correction methods, which can unintentionally shift the calibration
based on CO levels and barometric pressure conditions. In order to achieve a higher
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level of accuracy, the Series CDT includes digital barometric pressure adjustment and
the ability to field-calibrate the sensor.
Universal outputs allow users to select the transmitter output to be 4 to 20 mA, 0 to
5 VDC or 0 to 10 VDC to work with virtually any building management controller. An
optional relay with user adjustable set points can be used to control exhaust fans, open
actuated windows or dampers, or signal a light or horn.
For applications that require visual indication, the Series CDT and CDTR can be
ordered with the Model A-449 remote LCD display that can plug into the mini-connector
port on the internal circuit board. Both the CDT and CDTR can be configured to display
temperature only, CO only or CO and temperature together. The CDTR can also
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display relative humidity or CO and relative humidity together. Menu items that can
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be accessed include: engineering units, relay output set points, display configuration,
transmitter output scaling, ambient barometric pressure and field calibration of the
transmitter.
Single-beam dual-wavelength sensor advantages:
• Automatically corrects for aging effects in occupied and unoccupied buildings
◦ Perfect for hospitals and manufacturing plants that are occupied 24 hours per
day
• Measures actual unfiltered light intensity directly
◦ Eliminates error from incorrect assumptions of gas concentration in theoretical
logic assumption methods
DWYER INSTRUMENTS, INC.
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A.
1/8˝
[3.17]
Ø3-5/16˝
[84.14]
concentration and temperature
2
®
INSTALLATION
Make sure all connections are in accordance with the job wiring diagram and in
accordance with national and local electrical codes. Use copper conductors only.
transmitter to adjust to the current CO
days.
4-25/32˝
[121.44]
4-9/32˝
[108.74]
2-13/16˝
SPECIFICATIONS
Range: CO : 0 to 2000 or 0 to 5000 ppm (depending on model); RH: 0 to 100% (for
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units configured with humidity output); Temperature: 32 to 122°F (0 to 50°C).
Accuracy: ±40 ppm + 3% of reading (CO
humidity output); Temperature: ± 1°C @ 25°C.
Temperature Dependence: ±8 ppm / °C at 1100 ppm.
Non-Linearity: 16 ppm.
Pressure Dependence: 0.13% of reading per mm of Hg.
Response Time: 2 minutes for 99% step change.
Temperature Limits: 32 to 122°F (0 to 50°C).
Humidity Limits: 10 to 95% RH (non-condensing).
Power Requirements: 16 to 35 VDC / 19 to 28 VAC.
Power Consumption: Average: 2 watts; Peak: 3.75 watts.
Sensor: Single-beam, dual-wavelength NDIR.
Output: Current: 4 to 20 mA (max 500 Ω); Voltage: 0 to 5 VDC or 0 to 10 VDC
(min 500 Ω); Relay: SPST NO 2A @ 30 VDC; RTD or thermistor per r-t curves
(depending on model).
Weight: 5.6 oz (158.8 g).
Agency Approvals: CE.
Disconnect power supply before installation to prevent electrical
WARNING
shock and equipment damage.
Use electrostatic discharge precautions (e.g., use of wrist straps)
CAUTION
during installation and wiring to prevent equipment damage.
Avoid locations where severe shock or vibration, excessive
CAUTION
moisture or corrosive fumes are present.
Do not exceed ratings of this device, permanent damage not
CAUTION
covered by warranty may result.
NOTICE Upon powering the transmitter, the firmware version will flash on
the display. A warm up period of 30 minutes is required for the
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Self calibration feature of the transmitter requires exposure to
NOTICE
normal outdoor equivalent carbon dioxide level once every thirty
LEED ® is a registered trademark of the U.S. Green Building Council
Phone: 219/879-8000
Fax: 219/872-9057
Bulletin AQ-CDT/CDTR
11-49/64˝
[298.85]
[71.44]
Ø1-15/64˝
[31.35]
); RH: ±2% (for units configured with
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concentration.
www.dwyer-inst.com
e-mail: info@dwyermail.com