Chapter 5 Sequence of operations
Occupancy modes
Occupancy modes can be controlled by any of the following:
•The state of the local
•A timed override request from a Trane zone sensor (see “Timed over- ride control” on page 37)
•A communicated signal from a peer device (see
•A communicated signal from a BAS
A communicated request, either from a BAS or a peer controller, takes precedence over local requests. If a communicated occupancy request has been established and is no longer present, the controller reverts to the default (occupied) occupancy mode after 15 minutes (if no
•Occupied
•Unoccupied
•Occupied standby
•Occupied bypass
Occupied mode
In occupied mode, the controller maintains the zone temperature based on the occupied heating or cooling setpoints. The controller uses the occu- pied mode as a default mode when other forms of occupancy request are not present. The fan will run as configured (continuous or cycling). The outdoor air damper will close when the fan is off. The temperature set- points can be local
Unoccupied mode
In unoccupied mode, the controller attempts to maintain the zone temper- ature based on the unoccupied heating or cooling setpoint. The fan will cycle between high speed and off. The outdoor air damper will remain closed, unless economizing. The controller always uses the stored default setpoint values (configurable using the Rover service tool), regardless of the presence of a
Occupied standby mode
The controller is placed in occupied standby mode only when a communi- cated occupied request is combined with an unoccupied request from occupancy binary input BI3. In occupied standby mode, the controller maintains the zone temperature based on the occupied standby heating or cooling setpoints. Because the occupied standby setpoints are typically spread 2°F (1.1°C) in either direction and the outdoor air damper is closed, this mode reduces the demand for heating and cooling the space.
36 |
|
