ZEC410 VAV Controllers Installation Instructions
10
Sequence of Operation for Staged with Reheat Control
Occupied Mode:
When the zone temperature is between the occupied heating and cooling setpoints (inside of the
bias), the primary air damper is at the Minimum CFM and no mechanical heating runs. When the zone temperature
rises above the cooling setpoint, the primary air damper increases the cfm and no mechanical heating runs. If a
drop in zone temperature below the heating setpoint occurs, the supplemental heating coil is fully used before the
reheat heat coil enables, and the damper opens to provide to minimum cfm.
Note:
The box reheat and supplemental reheat is a box option. You have a cooling only box if you do not select
either reheat or supplemental reheat.
Unoccupied Mode:
In unoccupied mode, when the zone temperature is between the unoccupied heating and
cooling setpoints (inside of the bias), the primary air damper is at the minimum cfm and no mechanical heating
runs. When the zone temperature rises above the unoccupied cooling setpoint, the primary air damper increases
the cfm (if available), and no mechanical heating runs. When the zone temperature drops below the unoccupied
heating setpoint, the supplemental heating coil is fully used before the reheat heat coil enables. The damper is at
the minimum cfm.
Unit Enable:
A network unit enable signal controls the mode of the box.
Fan Control (Optional):
With parallel fans, when a call for heat occurs, the fan cycles on. In all other states the fan
remains off. With series fans, in occupied mode, the fan runs continuously. In unoccupied mode, the fan cycles on
with a call for heating or cooling.
Occupancy Lighting Switch (Optional):
You can add an occupancy lighting switch to the box, temporarily setting
the VAV box to Standby mode when the occupancy is not sensed. When the box senses occupancy, the zone
switches back to occupied. Standby mode uses standby temperature setpoints that are slightly highter or lower
than the occupied cooling or heating setpoints, respectively. The VAV box also uses unoccupied flow setpoints in
addition to the low temperatures.
Demand Control Ventilation (Optional):
When zone CO
2
sensors are wired to the boxes to sense the air quality
in the zone, the minimum damper flows are proportionally reset based on an air quality setpoint (CO
2
). The reset of
the damper minimum flows do not exceed the maximum value that you set. the CO
2
sensor with the highest value
determines the reset, if more than one is wired.
