551B,C
C06034
Fig. 33
and LED Locations
Replace the standard outside air dry bulb temperature sensor with the accessory enthalpy sensor in the same mounting location. (See Fig. 21.) Mount the return air enthalpy sensor in the return air duct. (See Fig. 35.) Wiring is provided in the EconoMi$er IV wiring harness. (See Fig. 27.) The outdoor enthalpy changeover set point is set with the outdoor enthalpy set point potentiometer on the EconoMi$er IV controller. When using this mode of changeover control, turn the enthalpy setpoint potentiometer fully clockwise to the D setting.
Indoor Air Quality (IAQ) Sensor Input
The IAQ input can be used for demand control ventilation control based on the level of CO2 measured in the space or return air duct.
Mount the accessory IAQ sensor according to manufacturer specifications. The IAQ sensor is wired to the AQ and AQ1 terminals of the controller. Adjust the DCV potentiometers to correspond to the DCV voltage output of the indoor air quality sensor at the
If a separate
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 modified with the Exhaust Fan Set Point (EXH SET) potentiometer. (See Fig. 33.) The set point 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. 33.) 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 VOC (volatile organic compound) ventilation 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
To determine the minimum position setting, perform the following procedure:
1.Calculate the appropriate mixed air temperature using the following formula:
(TO x 100OA ) + (TR x 100RA ) =TM
TO =
As an example, if local codes require 10% outdoor air during occupied conditions,
(60 x .10) + (75 x .90) = 73.5_F
2.Disconnect the supply air sensor from terminals T and T1.
3.Ensure that the
4.Connect 24 vac across terminals TR and TR1.
5.Carefully adjust the minimum position potentiometer until the measured supply air temperature matches the calculated value.
6.Reconnect the mixed air sensor to terminals T and T1.
Remote control of the EconoMi$er IV damper is desirable when requiring additional temporary ventilation. If a
To control the minimum damper position remotely, remove the
Damper Movement
Damper movement from full open to full closed (or vice versa) takes 21/2 minutes.
Thermostats
The EconoMi$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 does not support space temperature sensors. Connections are made at the thermostat terminal connection board located in the main control box.
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