Troubleshooting
Zone Ctrl II and
VAV Zone II Secondary Duct Installation and Start-up Guide
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To clean the airflow sensor orifice
In less than .02% of installations, small particulates (micron/submicron-level) can build up in the airflow sensor's
internal orifice causing airflow restriction. Symptoms of airflow restriction are:
•
Diffuser noise increases over time
•
Space overcools at minimum airflow
•
Frequency of dampers opening to maintain flow setpoint increases over time
•
AHU fan speed increases over time
To check for these symptoms, set up trending of:
•
Damper position to look for long term increase
•
AHU fan speed for maintaining static pressure
If you see these symptoms, you should clean the flow sensor.
To clean the flow sensor
You can use a can of compressed air to clean the sensors while the controller is installed or on a repair bench.
1
Disconnect the
High
and
Low
flow sensor tubes.
