2.Disconnect the supply-air sensor from termimds T and TI.

3.Ensure that file factory-installed jumper is in place across terminals P and PI. If remote damper positioning is being used, make sure that file tenninals are wired according to

Fig. 35 and that the minimum position potentiometer is turned fully clockwise.

4.Connect 24 vac across terminals TR and TRI.

5.Carefiflly adjust the minimum position potentiometer until the measured mixed-air temperature matches the c_dculated value.

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

Remote control of the EconoMiSerIV damper is desilable

when requiring additional tempormy ventilation. If a field-supplied remote potentiometer (Honeywell part number

$963B1128) is wired to the EconoMiSerIV controllek the min-

imum position of the damper can be controlled from a remote location.

To control the minimum damper position lemotely, remove

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

EconoMi$erIV controllec Wire the field-supplied potentiolne-

ter to the P and Pl terminals on the EconoMiSerIV controllec See Fig. 41.

Damper Movement -- Damper movement from full open to full closed (or vice velsa) takes 21/2 minutes.

Thermostats -- The EconoMiSerIV control works with con- ventional thermostats that have a YI (cool stage 1), Y2 (cool stage 2), WI (heat stage 1), W2 (heat stage 2), _md G (fan). The

EconoMiSerIV control does not support space temperature senso_.s. Connections are made at the thermostat terminal con- nection board located in the main control box.

Occupancy Control -- The factory default configuration for

the EconoMiSerIV control is occupied mode. Occupied status is provided by the red jumper from terminal 9 to terminal 10 on

TB2. When unoccupied mode is desired, install a field- supplied timeclock fimction in place of the jumper between ter- minals 9 and 10 on TB2. See Fig. 35. When the timeclock

contacts me closed, file EconoMiSer[V control will be in occupied mode. When the timeclock contacts are open (remov-

ing the 24-v signal from termimd N), the EconoMiSerlV will be in unoccupied mode.

Demand Controlled Ventilation (DCV) -- When using the

EconoMiSerlV for demand controlled ventilation, there me 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 c_d- culated to provide the desired fresh ail:

Typically file maximum ventilation rate will be about 5 to 10% more than the typical cfm required per pel.son, using

normal outside air design criteria.

A proportional anticipatory strategy should be taken with

the following conditions: a zone with a large area, varied occu- pancy, and equipment that cannot exceed the required ventila- tion rate at design conditions. Exceeding the required ventila- tion rate means the equipment can condition air at a maximum ventilation rate that is greater than the required ventilation rate

for maximum occupancy. A proportional-anticipatory strategy will cause file fresh air supplied to increase as the room COz

level increases even though the CO2 set point has not been reached. By the time the CO2 level reaches the set point, the dmnper will be at maximum ventilation and should maintain the set point.

In order to have the CO2 sensor control the economizer

dmnper in this manner, first determine the damper voltage out- put for minimum or base ventilation. Base ventilation is the

ventilation required to remove contmninants during unoccu-

pied periods. Tile following equation may be used to determine the percent of outside-air entering the building for a given damper position. For best results there should be at least a 10 degree difference in outside and return-air temperatures.

OA

RA

 

(To x l---ff_)+ (TR x _

) = TM

To = Outdoor-Air Temperature

OA = Percent of Outdoor Air

TR = Return-Air Telnperature

RA = Percent of Return Air

TM = Mixed-Air Temperature

Once base ventilation has been determined, set the mini- mum damper position potentiometer to the correct position.

The same equation can be used to determine the occupied or maximum ventilation rate to the building. For example, an out- put of 3.6 volts to the actuator provides a base ventilation rate of 5% and an output of 6.7 volts provides the maximum venti- lation rate of 20% (or base plus 15 cfm per person). Use Fig. 42

to determine the maximum setting of file CO2 sensoc For ex- ample, a 1100 ppm set point relates to a 15 cfm per person de- sign. Use the 1100 ppm curve on Fig. 42 to find the point when

the CO2 sensor output will be 6.7 volts. Line up the point on the graph with the left side of the chart to determine that the range configuration for the CO2 sensor should be 1800 ppm. The EconoMiSerIV controller will output the 6.7 volts fiom the CO2 sensor to the actuator when the CO__concentration in the

space is at 1100 ppm. The DCV set point may be left at 2 volts since the CO2 sensor voltage will be ignored by the EconoMiSerIV controller until it rises above the 3.6 volt setting of the minimum position potentiomete_:

Once the fully occupied dmnper position has been deter- mined, set file maximum dmnper demand control ventilation potentiometer to this position. Do not set to the maximum posi- tion as this can result in over-ventilation to the space and poten- tial high-humidity levels.

CO2_Sensor Configuration -- The CO2 sensor has preset standard voltage settings that can be selected anytime after the sensor is powered up. See Table 13.

Use setting 1 or 2 for Carrier equipment. See Table 13.

1.Press Clear and Mode buttons. Hold at least 5 seconds until the sensor enters the Edit mode.

2.Press Mode twice. The STDSET Menu will appear

3.Use the Up/Down button to select the preset numbel: See Table 13.

4.Press Enter to lock in file selection.

5.Press Mode to exit and resume norm_d operation.

The custom settings of the CO2 sensor can be changed any- time after the sensor is energized. Follow the steps below to change file non-stan&trd settings:

1.Press Clear and Mode buttons. Hold at least 5 seconds until the sensor enters the Edit mode.

2.Press Mode twice. The STDSET Menu will appem:

3.Use the Up/Down button to toggle to the NONSTD menu and press Entel:

4.Use the Up/Down button to toggle through each of the nine variables, starting with Altitude, until file desired set- ting is reached.

5.Press Mode to move through the variables.

6.Press Enter to lock in the selection, then press Mode to continue to the next vmiable.

28

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Image 28
Carrier 48TJ016-028 specifications To x l---ff+ TR

48TJ016-028 specifications

The Carrier 48TJ016-028 is a notable model in the range of packaged rooftop units designed by Carrier, a leader in heating, ventilation, and air conditioning (HVAC) solutions. Tailored specifically for commercial applications, these units provide a blend of efficiency, durability, and reliability, making them suitable for a variety of settings, including offices, retail spaces, and industrial environments.

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