Carrier 33ZCVAVTRM, 33ZCFANTRM, 33ZCSECTRM specifications Ventilation Rated Based on, CO2 Set Point

Fig. 19 — Ventilation Rated Based on

CO2 Set Point

Indoor Air Quality Sensor Wiring — To wire the sensors after they are mounted in the conditioned air space and return air duct, see Fig. 20 and the instructions shipped with the sen- sors. For each sensor, use two 2-conductor 18 AWG twisted- pair cables (unshielded) to connect the separate isolated 24 vac power source to the sensor and to connect the sensor to the con- trol board terminals. To connect the sensor to the control board, identify the positive (+) PIN-8 and ground (GND) PIN-7 termi- nals on the sensor and connect the positive terminal to terminal RH/IAQ and connect the ground terminal to terminal GND.

HUMIDITY SENSOR (WALL-MOUNTED) INSTALLA- TION — The accessory space humidity sensor is installed on an interior wall to measure the relative humidity of the air with- in the occupied space. See Fig. 21.

The use of a standard 2- x 4-in. electrical box to accommo- date the wiring is recommended for installation. The sensor can be mounted directly on the wall, if acceptable by local codes.

If the sensor is installed directly on a wall surface, install the humidity sensor using 2 screws and 2 hollow wall anchors (field-supplied); do not overtighten screws. See Fig. 11.

Do NOT clean or touch the sensing element with chemical solvents; they can permanently damage the sensor.

The sensor must be mounted vertically on the wall. The Carrier logo should be oriented correctly when the sensor is properly mounted.

DO NOT mount the sensor in drafty areas such as near heat- ing or air-conditioning ducts, open windows, fans, or over heat sources such as baseboard heaters, radiators, or wall-mounted light dimmers. Sensors mounted in those areas will produce in- accurate readings.

Avoid corner locations. Allow at least 4 ft between the sen- sor and any corner. Airflow near corners tends to be reduced, resulting in erratic sensor readings.

Sensor should be vertically mounted approximately 5 ft up from the floor, beside the space temperature sensor.

For distances up to 500 feet, use a 3-conductor, 18 or 20 AWG cable. A CCN communication cable can be used, although the shield is not required. The shield must be removed from the sensor end of the cable if this cable is used. See Fig. 22 for wiring details.

The power for the sensor is provided by the control board. The board provides 24 vdc for the sensor. No additional power source is required.

To wire the sensor, perform the following:

1.At the sensor, remove 4-in. of jacket from the cable. Strip 1/4-in. of insulation from each conductor. Route the cable through the wire clearance opening in the center of the sensor. See Fig. 22.

2.Connect the RED wire to the sensor screw terminal marked (+).

3.Install one lead from the resistor (supplied with the sensor) and the WHITE wire, into the sensor screw ter- minal marked (–). After tightening the screw terminal, test the connection by pulling gently on the resistor lead.

4.Connect the remaining lead from the resistor to the BLACK wire and secure using a closed end type crimp connector or wire nut.

5.Using electrical tape, insulate any exposed resistor lead to prevent shorting.

6.At the control box, remove the jacket from the cable and route the RED conductor over to the left side of the control board. Route the remaining conductors to the right side of the control board.

0

H F 2 3 B J 0 4 2

M a d e i n S w i t z e r l a n d b y B e l i m o A u t o m a t i o n

L R 9 2 8 0 0

NEMA 2

LISTED

94D5 U TEMP. IND. & L REG. EQUIP.

Class 2 Supply

5K

WIP

yel blu ora

		RH/IAQ
		GND
		1
35 in-lb (4 Nm)
80...110s
24VAC/DC
50/60Hz
3VA	2W
COM
1	2	3
blk	red	wht

21 87

24 VAC	LINE
	VOLTAGE

SEPARATE

ISOLATED

POWER

SUPPLY

REQUIRED

(24 VAC, 25 VA

MINIMUM)

*Do not connect to the same transformer that supplies power to the zone controller.

→Fig. 20 — Indoor Air Quality Sensor Wiring

25 303