eZV-440 Version 2.1 Application Guide
Page 16 of 67
Document Edition 2.5
3. Set Manual Balancing Dampers
In the Balancing Mode field, select OpenCmd_. This moves the VAV damper to its fully open
position and provides minimal airflow restriction to allow you to set the manual branch
balancing dampers.
4. Set the Airflow Setpoints
Adjust the cooling and heating minimum and maximum airflow setpoints as required in the
appropriate fields.
5. Check Airflow Zero Calibration
To verify the box zero without first doing an auto-zero calibration, in the Balancing Mode field
select CloseCmd_ to close the damper. Allow time for the damper to fully close. The airflow
reading should be zero or near zero if the airflow sensor has an accurate zero.
If the airflow is not at or near zero, visually check to make sure the damper is fully closed and
the associated VAV AHU is turned off. If you are still detecting some airflow, then the airflow
sensor needs to be zero-calibrated.
For more information about how to zero-calibrate the airflow sensor, see the section below.
To auto zero-calibrate the airflow sensor:
Note: For best results the AHU fan should be turned off when zeroing the airflow sensor.
1.
Click the Zero Calibrate button.
2.
Check the status of the airflow zero procedure by monitoring the Calibration Status
field:
•
If zero calibration has never been performed, the field will display NotComplete_.
•
When you are zero-calibrating the airflow sensor, the status InProgress_ is displayed.
•
When a zero-calibration has successfully completed, Complete_ is displayed.
•
If the zero-calibration is unsuccessful then Failed_ is displayed. An airflow zero fails
when the airflow reading is too far away from zero to be a simple sensor error, or when
the airflow readings are not stable. Possible reasons for a failed airflow zero include
sensor problems or the inability of the damper to fully close.
