Carrier 48TC*D08 appendix Supply Air Temperature SAT Sensor, Outdoor Air Lockout Sensor

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. 76.) This sensor is factory installed. The operating range of temperature measurement is 0° to 158_F (-18_to 70_C). See Table 15 for sensor temperature/resistance values.

The scale on the potentiometer is A, B, C, and D. See Fig. 74 for the corresponding temperature changeover values.

48TC

SUPPLY AIR

TEMPERATURE

SENSOR

MOUNTING

LOCATION

SUPPLY AIR

TEMPERATURE

SENSOR

C06033

Fig. 76 - Supply Air Sensor Location

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 airstream which is used to lock out the compressors below

a42_F (6_C) ambient temperature. (See Fig. 71.)

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. 74 for wiring information.

Determine the EconoMi$er IV control mode before set up of the control. Some modes of operation may require different sensors. (See Table 27.) The EconoMi$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.

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 setpoint selected on the control. If the outdoor-air temperature is above the setpoint, the EconoMi$er IV will adjust the outside air dampers to minimum position. If the outdoor-air temperature is below the setpoint, the position of the outside air dampers will be controlled to provided free cooling using outdoor air. When in this mode, the LED next to the free cooling setpoint potentiometer will be on. The changeover temperature setpoint is controlled by the free cooling setpoint potentiometer located on the control. (See Fig. 77.)

C06034

Fig. 77 - EconoMi$er IV 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
	11											A
	10										LED OFF
	9		50										100
	40	45		55	60	65	70	75	80	85	90	95
					DEGREES FAHRENHEIT

C06035

Fig. 78 - Outside Air Temperature Changeover

Setpoints

(cfm)	30
MINUTE
	25
PER	20
	15
FEET
	10
CUBICIN
	0
	5

FLOW	0.13	0.20	0.22	0.25	0.30	0.35	0.40	0.45	0.50
			STATIC PRESSURE (in. wg)

C06031

Fig. 79 - Outdoor-Air Damper Leakage

60