Trane N512, CNT-SVX07C-EN Occupancy modes, Occupied mode, Unoccupied mode, Occupied standby mode

Chapter 5 Sequence of operations

Occupancy modes

Occupancy modes can be controlled by any of the following:

•The state of the local (hard-wired) occupancy binary input BI3 (see “BI3: Occupancy or generic binary input” on page 15)

•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 “Peer-to-peer commu- nication” on page 48)

•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 hard-wired occupancy request exists). The Tracer ZN521 has the following occupancy mode options:

•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 (hard-wired), communicated, or stored default values (configurable using the Rover service tool).

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 hard-wired or communicated setpoint value.

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.

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