Carrier 48TM016-028

Outdoor Enthalpy Changeover — For enthalpy control, ac-

cessory enthalpy sensor (part number HH57AC078) is

required. Replace the standard outdoor dry bulb temperature

sensor with the accessory enthalpy sensor in the same mount-

ing location. See Fig. 33. 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 potentiometer on the EconoMi$erIV controller. The

set points are A, B, C, and D. See Fig. 41. The factory-installed

620-ohm jumper must be in place across terminals SR and SR+

on the EconoMi$erIV controller. See Fig. 33 and 42.

Differential Enthalpy Control — For differential enthalpy

control, the EconoMi$erIV controller uses two enthalpy sen-

sors (HH57AC078 and CRENTDIF004A00), one in the out-

side air and one in the return airstream or 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 out-

door) for cooling. For example, when the outdoor air has a low-

er enthalpy than the return air and is below the set point, the

EconoMi$erIV opens to bring in outdoor air for free cooling.

Replace the standard outside air dry bulb temperature sen-

sor with the accessory enthalpy sensor in the same mounting

location. See Fig. 33. Mount the return air enthalpy sensor in

the return airstream. See Fig. 40. The outdoor enthalpy

changeover set point is set with the outdoor enthalpy set point

potentiometer on the EconoMi$erIV controller. When using

this mode of changeover control, turn the enthalpy set point

potentiometer fully clockwise to the D setting.

NOTE: Remove 620-ohm resistor if differential enthalpy sen-

sor is installed.

Indoor Air Quality (IAQ) Sensor Input — The IAQ input

can be used for demand control ventilation control based on the

level of CO2measured in the space or return air duct.

Mount the accessory IAQ sensor according to manufacturer

specifications. The IAQ sensor should be wired to the AQ and

AQ1 terminals of the controller. Adjust the DCV potentiome-

ters to correspond to the DCV voltage output of the indoor air

quality sensor at the user-determined set point. See Fig. 43.

If a separate field-supplied transformer is used to power the

IAQ sensor, the sensor must not be grounded or the

EconoMi$erIV control board will be damaged.

Exhaust Set Point Adjustment — The exhaust set point will

determine when the exhaust fan runs based on damper position

(if accessory power exhaust is installed). The set point is modi-

fied with the Exhaust Fan Set Point (EXH SET) potentiometer.

See Fig. 36. The set point represents the damper position above

which the exhaust fan will be turned on. When there is a

call for exhaust, the EconoMi$erIV controller provides a

45 ± 15 second delay before exhaust fan activation to allow the

dampers to open. This delay allows the damper to reach the

appropriate position to avoid unnecessary fan overload.

Minimum Position Control — There is a minimum damper

position potentiometer on the EconoMi$erIV controller. See

Fig. 36. The minimum damper position maintains the mini-

mum airflow into the building during the occupied period.

When using demand ventilation, the minimum damper po-

sition represents the minimum ventilation position for VOC

(volatile organic compound) ventilation requirements. The

maximum demand ventilation position is used for fully occu-

pied ventilation.

When demand ventilation control is not being used, the

minimum position potentiometer should be used to set the oc-

cupied ventilation position. The maximum demand ventilation

position should be turned fully clockwise.

Adjust the minimum position potentiometer to allow the

minimum amount of outdoor air, as required by local codes, to

enter the building. Make minimum position adjustments with

at least 10° F temperature difference between the outdoor and

return-air temperatures.

To determine the minimum position setting, perform the

following procedure:

1. Calculate the appropriate mixed-air temperature using the

following formula:

TO= Outdoor-Air Temperature

OA = Percent of Outdoor Air

TR= Return-Air Temperature

RA = Percent of Return Air

TM= Mixed-Air Temperature

As an example, if local codes require 10% outdoor air

during occupied conditions, outdoor-air temperature is

60 F, and return-air temperature is 75 F.

(60 x .10) + (75 x .90) = 73.5 F

2. Disconnect the supply-air sensor from terminals T and

T1.

3. Ensure that the factory-installed jumper is in place across

terminals P and P1. If remote damper positioning is being

used, make sure that the terminals are wired according to

Fig. 36 and that the minimum position potentiometer is

turned fully clockwise.

4. Connect 24 vac across terminals TR and TR1.

5. Carefully adjust the minimum position potentiometer

until the measured mixed-air temperature matches the

calculated value.

6. Reconnect the supply-air sensor to terminals T and T1.

Remote control of the EconoMi$erIV damper is desirable

when requiring additional temporary ventilation. If a

field-supplied remote potentiometer (Honeywell part number

S963B1128) is wired to the EconoMi$erIV controller, the min-

imum position of the damper can be controlled from a remote

location.

To control the minimum damper position remotely, remove

the factory-installed jumper on the P and P1 terminals on the

EconoMi$erIV controller. Wire the field-supplied potentiome-

ter to the P and P1 terminals on the EconoMi$erIV controller.

See Fig. 40.

Damper Movement — Damper movement from full open to

full closed (or vice versa) takes 21/2minutes.

Thermostats — The EconoMi$erIV control works with con-

ventional thermostats that have a Y1 (cool stage 1), Y2 (cool

stage 2), W1 (heat stage 1), W2 (heat stage 2), and G (fan). The

EconoMi$erIV control does not support space temperature

sensors. Connections are made at the thermostat terminal con-

nection board located in the main control box.

Occupancy Control — The factory default configuration for

the EconoMi$erIV control is occupied mode. Occupied status

is provided by the black jumper from terminal TB2-9 to termi-

nal TB2-10. When unoccupied mode is desired, install a field-

supplied timeclock function in place of the jumper between

terminals TB2-9 and TB2-10. See Fig. 36. When the timeclock

contacts are closed, the EconoMi$erIV control will be in occu-

pied mode. When the timeclock contacts are open (removing

the 24-v signal from terminal N), the EconoMi$erIV will be in

unoccupied mode.

Demand Controlled Ventilation (DCV) — When using the

EconoMi$erIV for demand controlled ventilation, there are

some equipment selection criteria which should be considered.

When selecting the heat capacity and cool capacity of the

equipment, the maximum ventilation rate must be evaluated for

design conditions. The maximum damper position must be cal-

culated to provide the desired fresh air.

(TOxOA )+(TRxRA )=T

100 100