Carrier 50HE003-006, 50HJ004 Supply Air Temperature SAT Sensor, Outdoor Air Lockout Sensor

50HE,HJ

Supply Air Temperature (SAT) Sensor

The supply air temperature sensor is a 3 K thermistor located at the inlet of the indoor fan. (See Fig. 39.) This sensor is factory installed. The operating range of temperature measurement is 0° to 158_F. See Table 6 for sensor temperature/resistance values.

Table 6—Supply Air Sensor Temperature/

Resistance Values

TEMPERATURE (F)				RESISTANCE (ohms)
	–58			200,250
	–40			100,680
	–22			53,010
		–4		29,091
14				16,590
32				9,795
50				5,970
68				3,747
77				3,000
86				2,416
104				1,597
122				1,080
140				746
158				525
176				376
185				321
194				274
212				203
230				153
248				116
257				102
266				89
284				70
302				55
			17 1/4”

DIVIDER

OUTSIDE

AIR

HOOD

CLEANABLE ALUMINUM FILTER

FILTER

BAROMETRIC RELIEF

FILTER CLIP

C06027

Fig. 33 ---Filter Installation

The temperature sensor looks like an eyelet terminal with wires running to it. The sensor is located in the “crimp end” and is sealed from moisture.

Outdoor Air Lockout Sensor

The Economi$er IV is equipped with an ambient temperature lockout switch located in the outdoor air stream which is used to lockout the compressors below a 42_F ambient temperature. (See Fig. 27.)

Economi$er IV Control Modes

IMPORTANT: The optional EconoMi$er2 does not include a controller. The EconoMi$er2 is operated by a 4 to 20 mA signal from an existing field-supplied controller (such as PremierLink™ control). See Fig. 35 for wiring information.

Determine the EconoMi$er IV control mode before set up of the control. Some modes of operation may require different sensors. Refer to Table 7. The EconoMi$er IV is supplied from the factory with a supply-air temperature sensor and an outdoor- air temperature sensor. This allows for operation of the EconoMi$er IV with outdoor air dry bulb changeover control. Additional accessories can be added to allow for different types of changeover control and operation of the EconoMi$er IV and unit.

Table 7—Economi$er IV Sensor Usage

	ECONOMI$ER IV WITH OUTDOOR AIR
APPLICATION		DRY BULB SENSOR
		Accessories Required
Outdoor Air	None. The outdoor air dry bulb sensor
Dry Bulb		is factory installed.
Differential		CRTEMPSN002A00*
Dry Bulb
Single Enthalpy			HH57AC078
Differential			HH57AC078
					and
Enthalpy
		CRENTDIF004A00*
CO2 for DCV
Control using a		33ZCSENCO2
Wall-Mounted
CO2 Sensor
CO2 for DCV	33ZCSENCO2†			O
Control using a	and					CRCBDIOX005A00††
Duct-Mounted				R
	33ZCASPCO2**
CO2 Sensor

*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.

2sensor.

**33ZCASPCO2 is an accessory aspirator box required for duct-mounted applications.† 33ZCSENCO2 is an accessory CO

††CRCBDIOX005A00 is an accessory that contains both 33ZCSENCO2 and 33ZCASPCO2 accessories.

Outdoor Dry Bulb Changeover

The standard controller is shipped from the factory configured for outdoor dry bulb changeover control. The outdoor-air and supply-air temperature sensors are included as standard. For this control mode, the outdoor temperature is compared to an adjustable set point selected on the control. If the outdoor-air temperature is above the set point, the EconoMi$er IV will adjust the outdoor-air dampers to minimum position. If the outdoor air temperature is below the set point, the position of the outdoor air dampers will be controlled to provide free cooling using outdoor air. When in this mode, the LED next to the free cooling set point potentiometer will be on. The changeover temperature set point is controlled by the free cooling set point potentiometer located on the control. (See Fig. 40.) The scale on the potentiometer is A, B, C, and D. See Fig. 41 for the corresponding temperature changeover values.

Differential Dry Bulb Control

For differential dry bulb control the standard outdoor dry bulb sensor is used in conjunction with an additional accessory dry bulb sensor (part number CRTEMPSN002A00). The accessory sensor must be mounted in the return airstream. (See Fig. 42.) Wiring is provided in the EconoMi$er IV wiring harness. (See Fig. 33.)

In this mode of operation, the outdoor-air temperature is compared to the return-air temperature and the lower temperature airstream is used for cooling. When using this mode of changeover control, turn the enthalpy setpoint potentiometer fully clockwise to the D setting. (See Fig. 40.)

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