LX Series Unit Ventilator Controller User's Guide
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Occupancy Input
Use the switch closure on the occupancy input to set the Unit Ventilator Controller
to occupied mode. The UVC exits occupied mode when the switch is opened.
Unless the controller is in bypass mode, the occupied contact does not function if
the network variables nviOccCmd and nviOccManCmd are set to unoccupied.
Outdoor Enthalpy Input
Use outdoor air enthalpy to determine if free cooling is permitted. The Ventilator
Unit Controller also accepts input directly from an outdoor enthalpy sensor.
Outdoor Humidity Input
You can use outdoor humidity and temperature to calculate the outdoor enthalpy.
Outdoor enthalpy can be used to determine if free cooling is permitted.
Outdoor Temperature Input
If outdoor humidity is available, use outdoor temperature to calculate outdoor
enthalpy and Optimum Start times. Outdoor temperature or outdoor enthalpy is
used to determine if free cooling is permitted. See the
and
sections for more information.
Return Air Temperature Input
The return air temperature is used to prevent the coils from freezing due to cold
bypass air. See the
General Settings Configuration
section.
Position the return air temperature sensor either before or after the bypass damper.
Indicate the position of the return air temperature sensor in the General Settings tab
of the Ventilation Controller configuration wizard.
When the return air temperature sensor is positioned before the bypass damper,
return air temperature can be used instead of the space temperature. To do this, the
fan must be ON and the space temperature must be unavailable.
When the return air temperature sensor is positioned after the bypass damper, use
the following temperatures to calculate the required amount of intake air:
•
mixed air temperature
•
outdoor air temperature
•
return air temperature
Return air temperature can be monitored by an alarm. See the
Setpoint Offset Input
This input provides a means of varying the setpoint during occupied and standby
modes. The values from this input are added to the pair of active setpoints. See the