Bryant Complete HH57AC078 Manual and Sensor Usage Guide

Table 11 — EconoMi$erIV Sensor Usage

	ECONOMI$ERIV WITH OUTDOOR AIR		ECONOMI$ERIV WITH SINGLE
APPLICATION	DRY BULB SENSOR		ENTHALPY SENSOR
	Accessories Required		Accessories Required
Outdoor Air Dry Bulb	None. The outdoor air dry bulb sensor is factory installed.		CRTEMPSN002A00*
Differential Dry Bulb	CRTEMPSN002A00*		(2) CRTEMPSN002A00*
Single Enthalpy	HH57AC078		None. The single enthalpy sensor is factory installed.
Differential Enthalpy	HH57AC078
	and		CRENTDIF004A00*
	CRENTDIF004A00*
CO2 for DCV Control using a	CGCDXSEN004A00
Wall-Mounted CO2 Sensor
CO2 for DCV Control using a	CGCDXSEN004A00†
		and
Duct-Mounted CO2 Sensor
	CGCDXASP001A00**

*CRENTDIF004A00 and CRTEMPSN002A00 accessories are used on many different base units. As such, these kits may contain parts that will not be needed for installation.

†CGCDXSEN004A00 is an accessory CO2 sensor.

**CGCDXASP001A00 is an accessory aspirator box required for duct-mounted applications.

Differential Dry Bulb Control

For differential dry bulb control the standard outdoor dry bulb sensor is used in conjunction with an additional acces- sory return air sensor (part number CRTEMPSN002A00). The accessory sensor must be mounted in the return airstream. See Fig. 30.

In this mode of operation, the outdoor-air temperature is compared to the return-air temperature and the lower tem- perature airstream is used for cooling. When using this mode of changeover control, turn the free cooling/enthalpy set point potentiometer fully clockwise to the D setting. See Fig. 28.

Fig. 28 — EconoMi$erIV Controller Potentiometer

and LED Locations

19

	18	LED ON
				D
	17
	16		LED OFF		LED ON
						C
	15
mA	14				LED OFF			LED ON
									B
	13
	12							LED OFF		LED ON
												A
	11
	10										LED OFF
	9												100
	40	45	50	55	60	65	70	75	80	85	90	95
					DEGREES FAHRENHEIT

Fig. 29 — Outside Air Temperature

Changeover Set Points

IAQ	RETURN AIR
	TEMPERATURE
SENSOR	OR ENTHALPY
	SENSOR

Fig. 30 — Return Air Temperature or Enthalpy

Sensor Mounting Location

Outdoor Enthalpy Changeover

For enthalpy control, accessory enthalpy sensor (part num- ber HH57AC078) is required. Replace the standard outdoor dry bulb temperature sensor with the accessory enthalpy sensor in the same mounting location. See Fig. 25. When the outdoor air enthalpy rises above the outdoor enthalpy changeover set point, the outdoor-air damper moves to its minimum position. The outdoor enthalpy changeover set point is set with the outdoor enthalpy set point potentiome- ter on the EconoMi$erIV controller. The set points are A, B, C, and D. See Fig. 31. The factory-installed 620-ohm jumper must be in place across terminals SR and SR+ on the EconoMi$erIV controller. See Fig. 25 and 32.

Differential Enthalpy Control

For differential enthalpy control, the EconoMi$erIV controller uses two enthalpy sensors (HH57AC078 and CRENTDIF004A00), one in the outside air and one in the return airstream on the EconoMi$erIV frame. The EconoMi$erIV controller compares the outdoor air enthalpy to the return air enthalpy to determine EconoMi$erIV use. The controller selects the lower enthalpy air (return or outdoor)

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