Carrier 50TFQ008-012 specifications CO2 Sensor Standard Settings, Uration

CO2 sensor to the actuator when the CO2 concentration in the space is at 1100 ppm. The DCV set point may be left at 2 volts since the CO2 sensor voltage will be ignored by the EconoMi$er IV controller until it rises above the 3.6 volt set- ting of the minimum position potentiometer.

Once the fully occupied damper position has been deter- mined, set the maximum damper demand control ventilation potentiometer to this position. Do not set to the maximum posi- tion as this can result in over-ventilation to the space and poten- tial high-humidity levels.

CO2 Sensor Configuration — The CO2 sensor has preset standard voltage settings that can be selected anytime after the sensor is powered up. See Table 8.

Use setting 1 or 2 for Carrier equipment. See Table 8.

1.Press Clear and Mode buttons. Hold at least 5 seconds until the sensor enters the Edit mode.

2.Press Mode twice. The STDSET Menu will appear.

3.Use the Up/Down button to select the preset number. See Table 8.

4.Press Enter to lock in the selection.

5.Press Mode to exit and resume normal operation.

The custom settings of the CO2 sensor can be changed any- time after the sensor is energized. Follow the steps below to change the non-standard settings:

1.Press Clear and Mode buttons. Hold at least 5 seconds until the sensor enters the Edit mode.

2.Press Mode twice. The STDSET Menu will appear.

3.Use the Up/Down button to toggle to the NONSTD menu and press Enter.

4.Use the Up/Down button to toggle through each of the nine variables, starting with Altitude, until the desired set- ting is reached.

5.Press Mode to move through the variables.

6.Press Enter to lock in the selection, then press Mode to continue to the next variable.

Dehumidification of Fresh Air with DCV Control — Infor- mation from ASHRAE indicates that the largest humidity load on any zone is the fresh air introduced. For some applications, a device such as a 62AQ energy recovery unit is added to re- duce the moisture content of the fresh air being brought into the

building when the enthalpy is high. In most cases, the normal heating and cooling processes are more than adequate to re- move the humidity loads for most commercial applications.

If normal rooftop heating and cooling operation is not ade- quate for the outdoor humidity level, an energy recovery unit and/or a dehumidification option should be considered.

Step 7 — Adjust Indoor-Fan Speed — Adjust the indoor-fan speed to meet jobsite conditions.

For units with electric heat, required minimum cfm is 2250 for 50TFQ008, 2550 for 50TFQ009 and 3000 for 50TFQ012 with the following exceptions:

	UNIT	HEATER	UNIT	REQUIRED
UNIT			CONFIG-	MINIMUM
	VOLTAGE	kW
			URATION	CFM
	208/230	42.4	Horizontal	3200
	208/230	50.0	Horizontal	3200
50TFQ012	460	50.0	Horizontal or	3200
			Vertical
	575	17.0	Horizontal or	2800
		51.0	Vertical	2350

Table 9 shows indoor-fan motor data. Table 10 shows fan rpm at motor pulley settings for standard and alternate motors. Tables 11A and 11B show static pressure for accessories. Refer to Tables 12-27 to determine fan speed settings. Fan motor pulleys are factory set for speed shown in Table 1.

To change fan speeds:

1.Shut off the unit power supply and tag disconnect.

2.Loosen the belt by loosening the fan motor mounting nuts. See Fig. 38 and 39.

3.Loosen the movable pulley flange setscrew (see Fig. 40).

4.Screw the movable flange toward the fixed flange to increase speed or away from the fixed flange to decrease speed. Increasing the fan speed increases the load on the motor. Do not exceed the maximum speed specified in Table 1.

5.Set the movable flange at nearest keyway of the pulley hub and tighten the setscrew. (See Table 1 for speed change for each full turn of the pulley flange.)

Table 8 — CO2 Sensor Standard Settings

			VENTILATION	ANALOG	CO2	OPTIONAL	RELAY
SETTING	EQUIPMENT	OUTPUT	RATE		CONTROL RANGE	RELAY SETPOINT	HYSTERESIS
				OUTPUT
			(cfm/Person)		(ppm)	(ppm)	(ppm)
1		Proportional	Any	0-10V	0-2000	1000	50
				4-20 mA
2	Interface w/Standard	Proportional	Any	2-10V	0-2000	1000	50
	Building Control System			7-20 mA
3		Exponential	Any	0-10V	0-2000	1100	50
				4-20 mA
4		Proportional	15	0-10V	0-1100	1100	50
				4-20 mA
5		Proportional	20	0-10V	0- 900	900	50
				4-20 mA
	Economizer
6		Exponential	15	0-10V	0-1100	1100	50
				4-20 mA
7		Exponential	20	0-10V	0- 900	900	50
				4-20 mA
8	Health & Safety	Proportional	—	0-10V	0-9999	5000	500
				4-20 mA
9	Parking/Air Intakes/	Proportional	—	0-10V	0-2000	700	50
	Loading Docks			4-20 mA

LEGEND

ppm — Parts Per Million

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