Calibration Sequence - Trane Tracer VV550 Installation, Operation And Maintenance Manual

Table 20.Auto-commissioning test sequence (continued)
Item Test action
Local reheat
1. If no fan is present, open the air valve to the configured minimum local heating
b
electric
airflow.
2. If the fan is present, close the air valve and turn On the fan.
3. Record the auxiliary temperature.
4. Progressively turn On each local stage 30 seconds after the previous stage until all
stages are energized.
5. Record the auxiliary temperature 30 seconds after each stage is energized.
a. If there is no flow sensor, the controller runs in pressure dependent mode and record 40% and 100% during this auto-
commissioning step.
b. Requires a functional auxiliary sensor in the discharge air stream. The auxiliary sensor must be configured for discharge air
temperature.

Calibration Sequence

The calibration sequence enables the controller to calibrate the air valve position and the
water valve position. Calibration takes place if auto calibration is enabled and either a
power cycle or a transition from occupied to unoccupied has occurred.
Note: Whether or not auto calibration is enabled, the controller initiates calibration on a
The building automation system is responsible for the staggering of the calibration
sequence that is needed between units.
When auto calibration is enabled and a transition from occupied to unoccupied occurs,
the calibration sequence starts after a fixed delay of three minutes. The controller
effective occupancy mode is unoccupied, but runs like it is occupied during this three-
minute period.
The mode field of reported unit status reports calibration when the controller is in the
calibration sequence. If auto calibration is disabled, the air valve and water valve are not
driven closed and the flow sensor zero flow voltage reading is not recorded. Refer to
Table 21
Table 21.Calibration actions
I/O device
Air valve
Flow sensor
Modulating hot water reheat
Fan
Electric or On/Off hot water
CNT-SVX17G-EN
communicated application mode command.
for calibration actions.
Calibration action taken
Drive the air valve closed to the stroke
time plus 20 seconds.
Record the flow reading when the air valve
is fully closed.
Drive the water valve closed for the stroke
time plus 20 seconds.
Enabled
Disabled
Sequence of Operations
Reported data
Starting auxiliary
temperature and
the auxiliary
temperature for
each local stage of
electric heat
energized
Result after calibration
Initialize the air valve position as closed
when the air valve is over-driven.
Subtract the zero flow reading from all
subsequent readings.
Initialize the water valve position as closed
when the water valve is over-driven.
Enabled
Enabled
31