CNT-SVX04A-EN
Sequence of operation
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heating mode, when the space temperature is below the heat setpoint, the
primary heating capacity turns on. All capacity is turned off when the space
temperature is
between the unoccupied cooling and heating setpoints
. Note
that primary heating or cooling capacity is defined by unit type and whether
heating or cooling is enabled or disabled. For example, if the economizer is
enabled and possible, it will be the primary cooling capacity. If hydronic heating
is possible, it will be the primary heating capacity.
Occupied standby mode
To place the controller into the occupied standby mode, a communicated
occupancy request is combined with the local (hardwired) occupancy binary
input signal. When the communicated occupancy request is unoccupied, the
occupancy binary input (if present) does not affect the controller's occupancy.
When the communicated occupancy request is occupied, the controller uses
the local occupancy binary input to switch between the occupied and occupied
standby modes.
During occupied standby mode, the
controller's economizer damper position
goes to the economizer standby minimum
position. The economizer standby
minimum position can be changed using
Rover service tool.
In the occupied standby mode, the controller uses the occupied standby cooling
and heating setpoints. Because the occupied standby setpoints typically cover a
wider range than the occupied setpoints, the Tracer ZN.520 zone controller
reduces the control for heating and cooling the space by widening the comfort
zone. Also, the outdoor air economizer damper uses the economizer standby
minimum position to reduce the ventilation rate.
When no occupancy request is communicated, the occupancy binary input
switches the controller’s operating mode between occupied and unoccupied.
When no communicated occupancy request exists, the unit cannot switch to
occupied standby mode.
Occupied bypass mode
The controller can be placed in occupied bypass mode by either
communicating an occupancy request of Bypass to the controller or by using
the timed override on button on the Trane zone sensor.
When the controller is in unoccupied mode, you can press the On button on the
zone sensor to place the controller into occupied bypass mode for the duration
of the bypass time (typically, 120 minutes).
