Carrier 48TCA04---A12

Supply Air Temperature (SAT)Senso r

The supply air temperature sensor is a 3 K thermistor

located at the inlet of the indoor fan. (See Fig. 75.) This

sensor is factory installed. The operating range of

temperature measurement is 0°to 158_F(--18_to70_C).

See Table15 for sensor temperature/resistance values.

SUPPLY AIR

TEMPERATURE

SENSOR

MOUNTING

LOCATION

SUPPLY AIR

TEMPERATURE

SENSOR

C06033

Fig. 75 --Supply Air Senso r Location

The temperature sensor looks like an eyelet terminal with

wires running to it. The sensor is located in the “crimp

end” and is sealedfrom 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 tempera ture. (See Fig. 70.)

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 froman existing field-supplied controller

(such as PremierLink™control). See Fig. 72 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 22.) 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. 76.) The scale on the potentiometer is A, B, C,

and D. See Fig. 77 for the corresponding temperature

changeover values.

C06034

Fig. 76 --EconoMi$er IV Controller Potentiome ter

and LED Locations

LED ON

LED OFF

40 45 50 55 60 65 70 75 80 85 90 95 100

DEGREES FAHRENHEIT

C06035

Fig. 77 --Outside Air Temperature Changeover

Setpoints

0.13 0.20 0.22 0.25 0.30 0.35 0.40 0.45 0.50

STATICPRESSURE (in. wg)

FLOWIN CUBIC FEET PER MINUTE (cfm)

C06031

Fig. 78 --Outdoor--Air Damper Leakage

DifferentialDry 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. 79.) Wiring is

48TC