Installation and Maintenance Manual

VAV-SVX07A-EN 39
Tracer™ UC400 Controller Operations
closes the air valve if the configured airflow tracking offset is negative for flow tracking control
units. If the configured airflow tracking offset is positive, the controller opens the air valve to
the configured maximum airflow. Once a valid differential pressure is established through the
local hardwired input and no longer present, the controller generates a flow sensor failure
diagnostic.
Active Airflow Setpoint: The Tracer UC400 controller supports one modulating air valve for
heating and cooling operation. The controller positions the modulating air valve to deliver the
desired airflow (cooling or heating capacity). The desired airflow is called the active flow
setpoint. The airflow control algorithm compares the active airflow setpoint with the measured
airflow and calculates the necessary air valve movement to minimize error. The airflow setpoint
is limited by applicable minimum and maximum flow setpoints.
Space CO
2
Concentration: CO
2
-based demand control ventilation uses the space CO
2
value.
The controller compares the space CO
2
concentration to the configured band of CO
2
values and
determines the demand ventilation rate of the zone. The resulting ventilation rate is called the
effective ventilation setpoint. The effective ventilation setpoint is the outdoor airflow required
to provide ventilation. It is used to calculate the ventilation ratio of the zone.
Outputs
Damper Position: Indicates air valve or damper position.
Fan Output: The Fan will be shown as On, Off or None.
Heat Output: Will indicate reheat capacity in Percentage.
Analog Tab
Use the Analog tab to view the analog inputs, outputs, and values. These three categories are
presented in expanding boxes that stretch across the middle of the screen, and they are defined
from the factory. To expand the box and view its contents, click the arrow icon on the left side of
the box header in each category. View Details dialog boxes may be accessed by clicking on the
details buttons, located at the end of each line item.
Note: For field use of spare analog points, see BAS-SVX20*-EN.
Grid Columns
Index: Displays the sequence number assigned to the point.
Name: Displays the name of the point.
Value: Displays the current or assigned value of the point.
Units: Displays the units of measure in which the point is expressed.
State: Displays the state of the point. Point states are Normal, Out of Service, Fault, Locked,
and Alarm.
Control: Click to bring up the Override Request dialog box on which you can change the state
of the point.
Details: Accesses the View Details - Analog dialog box that contains information about each
point including its reference, priority, owner, and control time remaining for the current priority
level or state.
Binary Tab
Use the Binary tab to view the binary inputs, outputs, and values. These categories are presented
in expanding boxes that stretch across the middle of the screen, and they are defined from the
factory. To expand the box and view its contents, click the arrow icon on the left side of the box
header in each category. View Details dialog boxes may be accessed by clicking on the details
buttons, located at the end of each line item.
Note: For field use of spare analog points, see BAS-SVX20*-EN.