Balancing Airflow Sequence; Balancing Airflow Sequence; Dual Duct; Dual Duct - Nailor BAC-8001-36 Installation And Operation Manual

Floating reheat
If the controller is configured for floating reheat, it controls two binary triac outputs to drive the inputs of a tri-state actuator
connected to a valve. If the Reheat loop is less than 30%, the valve is driven closed. If the loop is greater than 70%, the valve is
driven open. If the loop is in between 30% and 70%, no valve action is taken.
See the topic Floating reheat on page 32 for an application drawing.
Figure 8-5 Floating reheat operation
HTG %
100
70
NO ACTION
30
0
Balancing Airflow Sequence
Balancing airflow is the process of calibrating the internal airflow sensor to a known standard. In the field, airflow is measured with
an airflow hood or other measuring instrument and then compared to the airflow measurements from the sensor in the controller.
The balancing process uses an STE-8001W36 or STE-8201W36 as the technicians setup tool for initiating the balancing sequence
and entering actual flow measurements.
When the balancing sequence starts, all other functions of the controller are locked out.
At the start of the sequence, the controller drives the damper open until the airflow reaches the highest value of either the cooling
or heating maximum airflow set points. An airflow measurement is made with an airflow hood and the actual airflow value is
entered into the controller. Once the actual airflow is entered, the controller drives the damper closed to the lower value of either
the cooling or heating minimum airflow. Another measurement is made with the flow hood and that measurement is entered into
the controller.
After the minimum airflow measurement is entered, the programming in the controller calculates airflow correction factors which
are used to adjust measurements from the internal airflow sensor. Balancing is complete and the controller is returned to normal
operation.
See the topic Balancing airflow on page 24 for the procedure to balance the airflow with an STE-8001W36.
Dual Duct
A dual duct installation consists of separate primary heating and cooling ducts, both with control dampers and airflow monitoring.
For this type of installation a EZvav BAC-8007-36 controls the cooling air (primary) damper and a TSP-8001-36 actuator controls
the heating air (secondary) damper.
• As the space temperature rises above the cooling set point, the primary airflow is modulated from the Cooling Minimum
flow to the Cooling Maximum Flow.
• As the space temperature falls below the heating set point, the secondary airflow is modulated from the Heating
Minimum flow to the Heating Maximum Flow.
• Between the heating and cooling set points, both the primary airflow and secondary airflow are modulated to maintain
the Dual Duct Minimum airflow.
See the topic, Dual duct application on page 33 for an application drawing.
Date: 10-2016 Supersedes: 7-2016
Nailor reserves the right to change any information concerning product or specification without notice or obligation.
Installation and Operation Manual
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HTG SPAN
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EZvav Digital Controls
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Room temp increase
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