Siemens 125-5050 사용자 설명서

Chapter 2 – Applications

Siemens Industry, Inc.

BACnet ATEC Owner's Manaul

125-5050, Rev. AA

4/20/2010

Calibration

Air Velocity Sensor

Calibration of the controller's internal air velocity sensor is periodically required to

maintain accurate air velocity readings. Calibration may be set to take place

automatically or manually.

Autozero Module (AZM)

Used when damper cannot be closed and constant airflow is needed.



For a controller used with an AZM, calibration occurs without closing the damper.

Application 6520, 6521, 6522, 6523.



For a controller used without an AZM, the damper is briefly commanded closed to

get a zero airflow reading and an accurate damper position during calibration.

Application 6520, 6521, 6522, 6523.

Hot Water Valve

Calibration of a hot water valve (if used) is done by briefly commanding the valve

closed. Application 2863, 2865, 2867.

Damper Status Operation

It is possible, after a period of operation, for the calculated damper position to differ

from the actual (physical) damper position.
If this occurs, the controller will

automatically compensate for any difference by

readjusting the calculated damper position. This calculated position may not match the

actual position.

Fail-safe Operation

If the air velocity sensor fails, the controller uses pressure dependent control. The

temperature loop controls the operation of the damper.
If the room temperature sensor fails, then the controller operates using the last known

temperature value.

Heating and Cooling Switchover

The heating/cooling switchover determines whether the controller is in heating or

cooling mode by monitoring the room temperature and the demand for heating and

cooling (as determined by the temperature control loops).