Application Information; Standalone; Occupied/Unoccupied; Timed Override - Trane Tracer AH.540 Installation Owner Diagnostics

Application information

Standalone

Occupied/unoccupied

You can configure the controller's binary input (IN 9) as an occupancy input to
switch between occupied and unoccupied modes of operation. When IN 9 is
configured as a normally open occupancy input, the standalone controller
switches to occupied mode when IN 9 contacts are open.

Timed override

The range for the timed override bypass time is 0 to 240 minutes (configurable).
The default value for the bypass time is 120 minutes.
The controller's space temperature analog input generates timed override On
and Cancel requests in the following manner. The controller interprets a
momentary short of the space temperature analog input as a timed override On
request. The controller always accepts this timed override On request and
resets the bypass time. The controller only changes to occupied bypass if the
controller is in either the unoccupied or occupied standby mode. The controller
stays in the occupied bypass mode for the occupied bypass time or until
someone presses the zone sensor's Cancel button.
The controller interprets a momentary fixed resistance of 1.5KΩ on the space
temperature analog input as a timed override Cancel request. The controller
always accepts the Cancel request and sets the bypass time to zero. The
controller only acts on a Cancel request during occupied bypass.

Morning warm-up and daytime warm-up

™
If the Tracer AH.540 controller is configured for constant volume discharge air
temperature control or variable air volume control, a space temperature sensor
can be wired to the controller to provide the morning warm-up and daytime
warm-up sequence of operation. The space temperature and setpoint inputs are
used by the controller to determine if heating or cooling air should be supplied
to the space.
In heating, the controller creates a supply air temperature according to the
configured discharge air heating setpoint or communicated discharge air
heating setpoint input. In cooling, the controller maintains a supply air
temperature according to the configured discharge air cooling setpoint or
communicated discharge air cooling setpoint input. If a valid communicated
discharge air setpoint exists, the controller uses the communicated value.

Configuration

Use Rover™ service tool to modify any of the controller's configuration
parameters. Refer to the literature supplied with the Rover service tool for more
information.

Setpoint operation

Standalone unit controllers can use two different stipend sources, the local
hardwired thumbwheel setpoint input or the default setpoints (nciSetpoints).
Use the thumbwheel setpoint input to provide the controller with a single
setpoint from which all other heating and cooling setpoints are derived.
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