Trane VAV VV550 LonTalk, Руководство по установке и эксплуатации

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VAV-SVP01A-EN 73
Sequence of Operations
This Comm5 controller supports an Electronically Commutated Motor (ECM). The controller turns
the ECM fan On and Off. It does not change the ECM fan airflow. To assist with flow balancing the
fan flow rate is stored as a configuration item.
Series Fan
The series fan is always controlled as a one-speed ON/OFF fan. The fan operates continuously in
the occupied or occupied standby mode. The fan cycles ON and OFF with calls for heating or
cooling in the unoccupied mode. The series fan operates in a manner that prevents reverse
rotational operation. The series fan is turned ON whenever one of the following occurs:
• Target airflow control point is greater than zero;
• Target air valve position is not closed;
• Actual air valve position is not closed.
Series fan operation during calibration
During calibration, the series fan is OFF unless the power-up control wait timer reaches zero. When
the power-up control wait timer reaches zero, the controller uses the normal series fan control logic.
The series fan is turned OFF for 10 seconds during calibration after the air valve closes all the way.
And, it remains OFF after the 10 seconds expires if:
• Power-up control wait time is still active;
• System mode (communicated application mode or communicated heat/cool mode) is ON;
• Effective occupancy mode is unoccupied.
Otherwise the series fan is turned ON when the 10-second period expires.
Parallel Fan
The parallel fan is the first stage of heat. When the primary air temperature is cold, the parallel fan:
• Cycles ON as the first stage of heat during occupied mode or occupied standby mode;
• Cycles ON with a call for heat during unoccupied mode.
When the primary air temperature is warm or hot, the parallel fan is OFF unless the local reheat
is ON. Two methods of control are supported for energizing the parallel fan. One method is based
on space temperature; the other method is based on primary airflow. The parallel fan start points
for each method of control are able to be configured.
Parallel fan start based on space temperature
The parallel fan turns ON when the space temperature falls below the heat setpoint plus the
configured parallel fan delta temperature enable setpoint. It turns OFF when the space temperature
rises above the heat setpoint plus the configured parallel fan delta temperature enable setpoint by
0.5°F (0.28°C).
Parallel fan start based on primary airflow
The parallel fan turns ON when the primary airflow falls below the configured parallel fan airflow
enable setpoint or the primary airflow is less than the active minimum flow setpoint plus 2% of the
configured nominal airflow. The parallel fan turns OFF when the primary airflow rises above the
configured parallel fan airflow enable setpoint plus 5% of the configured nominal airflow and the
primary airflow is greater than the active minimum flow setpoint plus 5% of the configured nominal
airflow. In pressure dependent mode, the air valve position is substituted for the primary airflow.
Parallel fan operation during calibration
During calibration, the parallel fan is in the same state (ON or OFF) as it was before calibration
started. It remains in that state until one minute after calibration ends. One minute after calibration
ends, normal control of the parallel fan resumes. The one-minute period is ignored if reheat is
active or if the parallel fan is overridden.