Dwyer Instruments CDTV Series Specifications-Installation And Operating Instructions Download Page 2

MOUNTING

1.  Cut hole into duct large enough to insert probe.

2.  Attach housing ears to duct using the two self-tapping screws provided.

3.  Knock out an opening in the housing and attach an electrical fitting to route    

    electrical wiring. PG11 & PG16 knockouts are molded into the housing.

WIRING

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

information.

Selection of Current and Voltage Outputs

Prior to wiring, verify that the current/voltage configuration switches (positions 1 and 2) 

are set to the desired output type. Refer to Figure 1 to locate the configuration switches. 

See Figure 2 for diagram of the current/voltage selection switches. For voltage output 

selection, the output can be 0 to 10 VDC, 0 to 5 VDC, 2 to 10 VDC or 1 to 5 VDC. See 

Figure 3 for the type of voltage output selection switches (positions 3 & 4).

Figure 2: Current/Voltage Output

Selection Jumper (PJ1 and PJ2)

Figure 3: Output range selection jumper

Figure 1: Diagram of circuit board

DOWN PUSH

BUTTON

CONFIGURATION

SWITCHES

TERMINAL

BLOCK

REMOTE DISPLAY

CONNECTOR

UP PUSH BUTTON

ENTER PUSH BUTTON

CO2 CONCENTRATION

OUTPUT SELECTION

VOC OUTPUT SELECTION

VOLTAGE

CURRENT

VOLTAGE

CURRENT

0-10 V

0-20 mA

2-10 V

4-20 mA

0-5 V

0-10 mA

1-5 V

2-10 mA

Current / Voltage Outputs

The transmitter may be wired for current or voltage output for both carbon dioxide and 

VOC. The transmitter can be powered with either 16 or 35 VDC or 19 to 28 VAC. Wire 

the transmitter according to Figure 4.

Thermistor and RTD Outputs

Thermistor and RTD passive outputs are located on terminals 7 and 8 and do not 

require any power. Passive temperature outputs are not polarity sensitive. 

Remote Display

Remote display Model A-449 can be used to display the VOC or 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 VOC or carbon dioxide 

measurements.

ACCESSING MENU PARAMETERS

Step 1:   To enter the menu structure, press         and         simultaneously for 5 

           seconds (display will show RON parameter).

Step 2:   Press         or         to cycle between menu items.

Step 3:   Press         to edit the value for the displayed menu item (SET will appear 

      

on  

display).

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

Step 5:   Press         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         and         

           simultaneously for 5 seconds or wait 10 seconds without pushing any    

      

buttons.

During the initial 5 minute warm-up phase, the VOC reading will be 0 ppm or an 

indeterminate value. After warming up, the device is operational and note the VOC 

output level will be approximately 450 PPM. If the device outputs 0 ppm after the 

warm-up, there is either an operational error or a disconnected sensor error and 

customer service should be contacted.

Note: 

Reference menu descriptions for changing factory settings.

PASSIVE

TEMPERATURE

SENSOR

RELAY

CONTACT

POWER

SUPPLY

VOC

RECEIVER

CO2

RECEIVER

Figure 4: Active output wiring diagram

Optional relay can be used as either a dry contact or low voltage 

switched circuit up to 2 A at 30 VDC.

NOTICE

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