Emerson 210-2000 Power Wiring, Analog Output Wiring, Relay Wiring, Reassembly After Wiring

Carbon Dioxide Sensor

Product Information Sheet 210-2000

Wiring

The mounting plate has two sets of three-terminal connectors. The connector on the left side of the mounting plate is where sensor power and the signal- to-I/O-board connection is made. The connector on the right side is where connection to the on-board relay is made.

Power Wiring

The CO2 sensor requires 24VAC power from a non- center-tapped transformer. The sensor draws a maximum of 3VA power. CPC recommends P/N 640- 0039, 10VA, 110VAC non-center-tapped Class 2 transformer.

Wire the transformer secondary to the connector on the left side of the mounting plate, as shown in Figure 2.

Analog Output Wiring

The middle terminal of the connector on the left side of the mounting plate is the analog output that communicates the current CO2 concentration level to the site controller. This connector is typically connected to a point on an I/O board, such as a 16AI, 16AIe, or 8DO. Wire the middle (SIGNAL) terminal on the CO2 sensor to the even numbered terminal of the I/O board point. Wire the COMMON terminal on the CO2 sensor to the odd numbered terminal of the I/O board point. See Figure 2.

Relay Wiring

The CO2 sensor has an on-board relay that changes state to indicate a CO2 level higher that a programmed set point. This relay can be used as a digital input on an input board point, or it can be used to directly activate or deactivate an alarm annunciator or a device that controls ventilation.

The connector on the right side of the mounting plate is a Form C connector for the CO2 sensor relay. Connect the input board point or device to the

middle (COMMON) terminal of this connector, and either the N.C. or N.O. terminal, depending on whether you want the relay to be OPEN or CLOSED when the CO2 concentration is below the set point. See Figure 2.

Figure 2 - CO2 Sensor Wiring

Reassembly After Wiring

When you are finished wiring power and I/O to the connectors on the mounting plate, reconnect the circuit board to the mounting plate. Push the top end of the circuit board into the mounting plate so the two hooked tabs on the circuit board are underneath the tabs on the mounting plate. Then, gently press down on the bottom part of the circuit board until it snaps into place. See Figure 3.

If you have trouble pushing the circuit board in, check to see if the pins on the back of the circuit board are properly aligned with the power and relay connectors on the mounting plate. Also verify that there are no loose wires getting in the way.

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