Single-Star (*) And Double-Star (**) Thumbwheel Settings - Trane Tracer VV550 Installation, Operation And Maintenance Manual

These setpoint limits apply only to the occupied and occupied standby, heating, and
cooling setpoints. They do not apply to the unoccupied heating and cooling setpoints.
When the controller is in the unoccupied mode, it always uses the unoccupied heating
and cooling setpoints.
Unit configuration enables or disables the local (hardwired) setpoint. This parameter
provides additional flexibility to allow you to apply communicated, hardwired, or default
setpoints without making physical changes to the unit.
Similar to hardwired setpoints, the effective setpoint value for a communicated setpoint
is determined based on the stored default setpoints, configuration values, and the
controller occupancy mode.

Single-Star (*) and Double-Star (**) Thumbwheel settings

Positioning the thumbwheel at the single star (*) setting generates an override to cooling
minimum flow. The override is enabled when the setpoint is greater than 88°F (31.11°C)
and disabled when the setpoint is less than 87.7°F (30.94°C).
Positioning the thumbwheel at the double star (**) setting generates an override to
cooling maximum flow. The double-star function is enabled when the setpoint is less
than 48.5°F (9.17°C) and disabled when the setpoint is greater than 50°F (10°C).
Note: The maximum flow and the minimum flow overrides generated by using the
Positioning the thumbwheel past the single star or double star sometimes generates a
Local Setpoint failure diagnostic.
Consider the following:
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CNT-SVX17G-EN
thumbwheel have priority over the communicated flow override network variable.
If the thumbwheel is not enabled, locally generated overrides (maximum flow or
minimum flow) are not possible.;
Single star and double star airflow override capability can be disabled through
configuration, while leaving the thumbwheel local setpoint enabled;
The controller communicates an active override by setting the mode field in the
reported unit status and the reported heat/cool mode to TEST;
There is no effect on the fan and the reheat operation during the single star and double
star thumbwheel airflow overrides. When the single star and double star thumbwheel
airflow overrides are active, the default space setpoints are used, the reported local
setpoint reports the invalid value. Setpoint values outside of the valid setpoint range
(50°F to 85°F [10.0°C to 29.44°C]) are not used.
Inputs and Outputs
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