Carrier 33ZCFANTRM, 33ZCVAVTRM, 33ZCSECTRM specifications Indoor Air Quality CO2 Sensor, 33ZCSENCO2

PRIMARY AIR INLET

UNIT WITH ELECTRIC REHEAT

2 FT. MIN.

AIR

TERMINAL

UNIT

ZC HEAT SAT

UNIT WITH OCTOPUS

PRIMARY

AIR INLET

ZC — Zone Controller

		2 FT. MIN.
	AIR	OCTOPUS
TERMINAL
	UNIT
ZC	HEAT	SAT

→ Fig. 17 — Supply Air Temperature Probe (Part No. 33ZCSENSAT) Locations

The CO2 sensors (33ZCSENCO2) factory set for a range of 0 to 2000 ppm and a linear voltage output of 0 to 10 vdc. Figure 19 shows ventilation rates for various CO2 set points when outside air with a typical CO2 level of 350 ppm is used. Refer to the instructions supplied with the CO2 sensor for elec- trical requirements and terminal locations. The zone controller requires 24 vac 25 va transformer to provide power to the sensor.

To convert the CO2 sensor into a duct-mounted CO2 sensor, the duct-mounted aspirator (33ZCASPCO2) will need to be purchased.

To accurately monitor the quality of the air in the condi- tioned air space, locate the sensor near the return air grille so it senses the concentration of CO2 leaving the space. The sensor should be mounted in a location to avoid direct breath contact.

Do not mount the space sensor in drafty areas such as near supply ducts, open windows, fans, or over heat sources. Allow at least 3 ft between the sensor and any corner. Avoid mounting the sensor where it is influenced by the supply air; the sensor gives inaccurate readings if the supply air is blown directly onto the sensor or if the supply air does not have a chance to mix with the room air before it is drawn into the return air stream.

5.625

(14.3)

3.25

(8.3)

1.125

(2.9)

5

(12.7)

0.25

(0.8)

To accurately monitor the quality of the air in the return air duct, locate the sensor at least 6 in. upstream or 15 in. down- stream of a 90 degree turn in the duct. The downstream loca- tion is preferred. Mount the sensor in the center of the duct.

IMPORTANT: If the sensor is mounted in the return air duct, readjust the mixed-air dampers to allow a small amount of air to flow past the return air damper when- ever the mixing box is fully open to the outside air. If the damper is not properly adjusted to provide this mini- mum airflow, the sensor may not detect the indoor-air quality during the economizer cycle.

Fig. 18 — Indoor Air Quality (CO2) Sensor

(33ZCSENCO2)

303 24