CO2-D/CO2-W Alarm Output


  1. Please verify whether terminal nr 1 & 2 of CO2-D/CO2-W is a NO/NC relay contact point or any other point which gives 12VDC output voltage. (it is not so clear as per the technical catalogue attached below)
  2. If it is NO/NC point, what is the maximum rated amperage that can be drawn across?

  1. The relay connection diagram corresponding to ports 1 and 2 is as follows:
    You can connect 12V AC or DC power supply to port 2. Connect a load less than 36W to port 1.
  2. The maximum rated current is 12V (DC/AC) /3A
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However, will it be possible to connect 24 VAC/VDC across the above terminal (terminal 1 & 2) by any chance??

It is easier to drive the same power supply which is used to power up the sensor (24VAC) across the relay point (terminal 1 & 2) so that we can energize a 24VAC external relay using above power supply. This external relay will be used to operate a Fresh Air Fan based on the CO2 level.
If not, we will have to use separate 12V supply to energize this external relay which is complicated and troublesome.

FYI: We have driven 24VAC power supply across terminal 1&2 in a previous application and energized an external relay. This set up is still working fine.

24 V AC or DC is allowed to be connected to terminal 2, and you can power it with a total power supply

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Any particular reason for connecting 24VAC/VDC to terminal 2, and avoid terminal 1??

From what I could tell on the PCB layout, this is a dry contact output. You can tie power to terminal1 and have the output on terminal2. Or you could bring the power in on terminal 2 and it goes out on terminal1.

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