Carrier 48TJ016-028 - Manual (Page 28)

2. Disconnect the supply-air sensor from termintils T and
Tl.
3. Ensure that tire factoiy-installed jumper is in place across
terminals P and PI. If remote damper positioning is being
used, make sure that tire tenninals are wired according to
Fig. 35 and that the irrinimuirr position potentiometer is
turned fully clockwise.
4. Connect 24 vac across tenninals TR and TRl.
5. Carefully adjust the minimum position potentiometer
until the measured mixed-air temperature matches the
calculated value.
6. Reconnect the supply-air sensor to tenninals T and Tl.
Remote control of the EconoMi$erIV damper is desirable
when requiring additional temporaiy ventilation. If a
field-supplied remote potentiometer (Honeywell part number
S963B1128) is wired to the EconoMi$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 factoiy-installed jumper on the P and PI terminals on the
EconoMi$erIV controller. Wire tire field-supplied potentiome­
ter to the P and PI terminals on the EconoMi$erIV controller.
See Fig. 41.
Damper Movement — Damper movement from full open to
full closed (or vice veraa) tiikes 2
'/2
minutes.
Thermostats — Tfie EconoMi$erIV control works with con­
ventional thermostats that have a Y1 (cool stage 1), Y2 (cool
stage 2), W1 (heat stage 1), W2 (heat stage 2), and G (fan). The
EconoMi$eiTV control does not support space temperature
sensora. Connections are made at the thermostat terminal con­
nection board located in the main control box.
Occupancy Control — Tire factoiy default configuration for
the EconoMiSerlV 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 function in place of the jumper between ter­
minals 9 and 10 on TB2. See Fig. 35. When the timeclock
contacts ai'e closed, tire EconoMiSerfV control will be in
occupied mode. When the timeclock contacts are open (remov­
ing 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 tu'e
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 ciil-
culated to provide the desired fresh air
Typically tlie maximum ventilation rate will be about 5 to
10% more than the typical cfm required per pereon, using
normal outside air design criteria.
A proportional anticipatoiy 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 propoitional-anticipatoiy strategy
will cause tlie fresh air supplied to increase as the room CO
2
level increases even though the CO 2 set point has not been
reached. By the time the CO
2
level reaches the set point, the
damper will be at maximum ventilation and should msiintain
the set point.
In order to have the CO 2 sensor control the economizer
diunper in this manner, first detemiine tlie damper voltage out­
put for minimum or base ventilation. Base ventilation is the
ventilation required to remove contaminants during unoccu­
pied periods. The 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.
(Tox ^"^-) -H(TRx-®^^
100 100
) = T m
To = Outdoor-Air Temperature
OA = Percent of Outdoor Air
T r = Return-Air Temperature
RA = Percent of Return Air
T m = Mixed-Air Temperature
Once base ventilation has been determined, set the mini­
mum damper position potentiometer to the correct position.
Tlie same equation can be used to detennine 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 detennine the maximum setting of tlie CO
2 sensor. 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 CO
2 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 CO
2 sensor should be 1800 ppm. The
EconoMi$erIV controller will output the 6.7 volts from the
CO
2 sensor to the actuator when the CO 2 concentration in the
space is at 1100 ppm. Tire DCV set point may be left at 2 volts
since the CO
2 sensor voltage will be ignored by the
EconoMi$erIV controller until it rises above the 3.6 volt setting
of the minimum position potentiometer.
Once the fully occupied diunper position has been deter­
mined, set tire maximum danper 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.
CQ t Sensor Configuration — The CO 2 sensor has preset
standard voltage settings tirat 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. Tlie STDSET Menu will appear.
3. Use tlie Up/Down button to select the preset number. See
Table 1.3.
4. Press Enter to lock in tlie selection.
5. Press Mode to exit and resume normal operation.
Tlie custom settings of the CO 2 sensor can be changed any­
time after the sensor is energized. Follow the steps below to
change tlie non-standard settings:
1. Press Clear and Mode buttons. Hold at least 5 seconds
until the sensor enters the Edit mode.
2. Press Mode twice. Tlie STDSET Menu will appear.
3. Use the Up/Down button to toggle to the NONSTD menu
and press Enter.
4. Use the Up/Down button to toggle through each of the
nine variables, starting with Altitude, until tlie 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 viuiable.
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