Carrier 50TC*17 Series Service And Maintenance Instructions page 45

CO SENSOR MAX RANGE SETTING
2
6000
5000
4000
3000
2000
1000
0
2 3 4
DAMPER VOLTAGE FOR MAX VENTILATION RATE
Fig. 56 − CO Sensor Maximum Range Settings
2
If a separate field-supplied transformer is used to power
the IAQ sensor, the sensor must not be grounded or the
EconoMi$er IV control board will be damaged.
When using demand ventilation, the minimum damper
position represents the minimum ventilation position for
VOC (volatile organic
requirements. The maximum demand ventilation position
is used for fully occupied ventilation.
When demand ventilation control is not being used, the
minimum position potentiometer should be used to set the
occupied ventilation position. The maximum demand
ventilation position should be turned fully clockwise.
Exhaust Setpoint Adjustment
The exhaust setpoint will determine when the exhaust fan
runs based on damper position (if accessory power
exhaust is installed). The setpoint is modified with the
Exhaust Fan Setpoint (EXH SET) potentiometer. See Fig.
50. The setpoint represents the damper position above
which the exhaust fans will be turned on. When there is a
call for exhaust, the EconoMi$er IV 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$er IV controller. See Fig. 50. The minimum
damper position maintains the minimum airflow into the
building during the occupied period.
When using demand ventilation, the minimum damper
position represents the minimum ventilation position for
Volatile Organic Compound
requirements. The maximum demand ventilation position
is used for fully occupied ventilation.
When demand ventilation control is not being used, the
minimum position potentiometer should be used to set the
occupied ventilation position. The maximum demand
ventilation position should be turned fully clockwise.
Adjust the minimum position potentiometer to allow the
minimum amount of outdoor air, as required by local
codes, to enter the building. Make minimum position
adjustments with at least 10_F temperature difference
between the outdoor and return-air temperatures.
800 ppm
900 ppm
1000 ppm
1100 ppm
5 6 7 8
C06039
compounds) ventilation
(VOC) ventilation
To determine the minimum position setting, perform the
following procedure:
1. Calculate the appropriate mixed air temperature
using the following formula:
OA
(T
O x
100
T = Outdoor-Air Temperature
O
OA = Percent of Outdoor Air
T = Return-Air Temperature
R
RA = Percent of Return Air
T = Mixed-Air Temperature
M
As an example, if local codes require 10% outdoor
air during occupied
temperature is 60_F, and return-air temperature is
75_F.
(60 x .10) + (75 x .90) = 73.5_F
2. Disconnect the supply air sensor from terminals T
and T1.
3. Ensure that the factory-installed jumper is in place
across terminals P and P1. If remote damper
positioning is being used, make sure that the
terminals are wired according to Fig. 52 and that the
minimum position potentiometer is turned fully
clockwise.
4. Connect 24 vac across terminals TR and TR1.
5. Carefully adjust
potentiometer until
temperature matches the calculated value.
6. Reconnect the supply air sensor to terminals T and
T1.
Remote control of the EconoMi$er IV damper is desirable
when requiring additional temporary ventilation. If a
field-supplied remote potentiometer (Honeywell p/n:
S963B1128) is wired to the EconoMi$er IV controller, the
minimum position of the damper can be controlled from a
remote location.
To control the minimum damper position remotely,
remove the factory-installed jumper on the P and P1
terminals on the EconoMi$er IV controller. Wire the
field-supplied potentiometer to the P and P1 terminals on
the EconoMi$er IV controller. (See Fig. 54.)
Damper Movement
Damper movement from full open to full closed (or vice
1
versa) takes 2 / minutes.
2
Thermostats
The EconoMi$er IV control works with conventional
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$er IV control
temperature sensors. Connections are made at the
thermostat terminal connection board located in the main
control box.
Occupancy Control
The factory default configuration for the EconoMi$er IV
control is occupied mode. Occupied status is provided by
the black jumper from terminal TR to terminal N. When
45
RA
) + (TR
x
) =T
M
100
conditions, outdoor-air
the minimum position
the measured mixed air
does not support space