Dwyer Instruments CDT-2N44-LCD, CDTR-2N4A4-LCD, CDTR Series Installation And Operating Instructions Manual

Series CDT and CDTR Wall Mount Carbon Dioxide/

[92.72]

[71.12]

1.10

®

Temperature Transmitter

Specications - Installation and Operating Instructions

Bulletin AQ-CDT/CDTR-E/N

3.65

North AmericanEuropean

Series CDT and CDTR Wall Mount Carbon Dioxide Temperature Transmitters

accurately monitor the CO
and other indoor environments to help achieve LEED

Series CDTR also measures ambient relative humidity. 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
pressure conditions. In order to achieve a higher level of accuracy, the Series CDT
includes digital barometric pressure adjustment and the ability to eld-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 an integral LCD display, Model A-449 or Model A-449A remote LCD
display that can plug into the mini-connector port on the side of the transmitter. Both
the CDT and CDTR can be congured to display temperature only, CO
and temperature together. The Series CDTR can also display relative humidity or

2 and relative humidity together. Push buttons are standard on the transmitters for

CO

access to the menu structure, but the transmitter can be ordered without the buttons.
To prevent tampering, the action of the buttons can be locked out using an internal dip
switch selection. Menu items that can be accessed include: engineering units, relay
output set points, display conguration, transmitter output scaling, ambient barometric
pressure and eld 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 unltered light intensity directly
◦ Eliminates error from incorrect assumptions of gas concentration in theoretical
logic assumption methods

* For buildings occupied 24 hours per day, it is recommended that calibration be
veried every 6 to 12 months depending on application.

2 concentration and temperature in schools, ofce buildings,

®

certication. Additionally, the

2 levels and barometric

2 only, or CO2

1.08

[27.33]

4.50

[114.30]

3.56

[90.42]

SPECIFICATIONS
Sensor: Single beam, dual-wavelength NDIR.
Range: CO

122°F (0 to 50°C).

Accuracy: CO

congured with 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 min 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 or 19 to 28 VAC.
Power Consumption: Average: 2 w; Peak: 3.75 w.
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 rated 2A @ 30 VDC; RTD or thermistor per r-t
curves on page 4 (depending on model).

Weight: 4.4 oz (125 g).
Agency Approvals: CE.

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.

2: 0 to 2000 or 0 to 5000 ppm (depending on model); Temperature: 32 to

2: ±40 ppm ±3% of reading; RH: ±2% (10 to 90% RH) (for units

CAUTION

NOTICE

NOTICE

NOTICE

NOTICE

NOTICE

Disconnect power supply before installation to prevent electrical
shock and equipment damage.

Use electrostatic discharge precautions (e.g., use of wrist straps)
during installation and wiring to prevent equipment damage.

Avoid locations where severe shock or vibration, excessive
moisture or corrosive fumes are present.

Do not exceed ratings of this device, permanent damage not
covered by warranty may result.

Upon powering the transmitter, the rmware version will ash on
the display. A warm up period of 30 minutes is required for the

2 concentration.

Self calibration feature of the transmitter requires exposure to
normal outdoor equivalent carbon dioxide level once every thirty

2.80

[27.96]

DWYER INSTRUMENTS, INC.

P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A.

LEED® is a registered trademark of the U.S. Green Building Council

Phone: [phone]

Fax: [phone]

www.dwyer-inst.com

e-mail: [e-mail]

Current / Voltage Outputs

TURE

POWER

TEMP OR RH

On the Series CDT, the transmitter may be wired for current or voltage output for both
carbon dioxide and temperature. On the Series CDTR, the transmitter may be wired
for current or voltage output for both carbon dioxide and humidity. The transmitter can
be powered with either 16 to 35 VDC or 19 to 28 VAC. Wire the transmitter according
to Figure 4.

NOTICE

Optional relay can be used as either a dry contact or low voltage
switched circuit up to 2 A at 30 VDC

Figure 1: Removal Of Cover From Back Plate

MOUNTING

1. Push tab on top and bottom of cover and lift cover from back plate (See Figure 1).

2. Select the mounting location, away from diffusers, lights or any external
inuences.

3. Mount transmitter on a vertical surface to a standard electrical box using the two
#6 M2C type screws provided.

4. Pull wires through sub base hole and make necessary connections.

5. Reattach cover to base plate.

WIRING

Use maximum 18 AWG wire for wiring to terminals. Refer to Figure 4 for wiring
information.

Dip Switch

Figure 2: Diagram Of Circuit Board

DIP SWITCH SETTINGS

To access the DIP SWITCH, remove the cover of the unit as shown in Figure 2. The
DIP SWITCH is located on the back of the circuit board.

SUPPLY

RECEIVER

CO2

RECEIVER

RELAY
CONTACT

PASSIVE
TEMPERA
SENSOR

Figure 4: Active Output Wiring Diagram

Remote Display

For models that are ordered without an integral LCD display, remote display Model
A-449 can be used to display the temperature, humidity, and carbon dioxide. The mini
USB plug of the remote display plugs into the receptor on the side of the housing.
After a short warm up time, the display will begin to show the current temperature and
carbon dioxide measurements unless congured by the user to show humidity and
carbon dioxide, only temperature, only humidity, or only carbon dioxide.

EDITING MENU PARAMETERS

Before any adjustment can be made to the transmitter, the Menu Lockout Dip Switch
must be set to the ˝On˝ position (See Figure 3)

Enter

Remote Display Port

Up

UP = “ON”
DOWN = “OFF”

DIP SWITCH #1

DIP SWITCH #6

DIP SWITCH

Figure 3

DIP Switch Position 1: CO

2 Output Selection

ON: Output set to voltage output
OFF: Output set to current output

DIP Switch Position 2: Temperature (CDT models) / Humidity (CDTR models)
Output Selection

ON: Output set to voltage output
OFF: Output set to current output

DIP Switch Positions 3 & 4: Current or Voltage Output Range Selection

Output Range DIP Switch 3 Position DIP Switch 4 Position
2 to 10 V

ON OFF
4 to 20 mA
0 to 10 V

OFF OFF
0 to 20 mA
0 to 5 V

OFF ON
0 to 10 mA
1 to 5 V

ON ON
2 to 10 mA

Dip Switch Position 5: Menu Access

ON: Menu Enabled
OFF: Menu Disabled

Down

Figure 5: Side View of Transmitter

ACCESSING MENU PARAMETERS

Step 1: To enter the menu structure, press Up button and Down button
simultaneously for 5 seconds (display will show RON parameter).

Step 2: Press Up button or Down button to cycle between menu items.

Step 3: Press Enter to edit the value for the displayed menu item (SET will appear
on display).

Step 4: Press Up button or Down button to adjust the value of the menu item.

Step 5: Press Enter button to save the changes (SET will disappear).

Step 6: Repeat Steps 2 through 5 for each of the parameters.

Step 7: To exit the menu at any time, press and hold Up button and Down button
simultaneously for 5 seconds or wait 10 seconds without pushing any
buttons.