Issue
A floating control reheat valve is wired to the digital triac outputs of a MicroSmart controller. After a few hours of operation, the valve position does not match with the expected position as provided by the real-time display. Is there a way to synchronize the actual position with the real-time display without power-cycling the controller?
Environment
DMS
MicroSmart (any with triac outputs)
Cause
Intrinsic design issue with floating actuators with built-in feedback.
Resolution
One option is to write a UDP that toggles valve control using a STOP command and then an AUTO command on the analog output point.
Ensure the STOP command action is RANLO (range low) which will swing the actuator to its fully open or fully closed position. The AUTO command will restore dynamic control via its control loop.
In between the STOP and AUTO commands, insert a delay of 120 seconds to give the actuator time to get to its fully open or fully closed position. If the actuator needs more or less than 120 seconds, modify it accordingly.
Run the UDP on a timer of every 4 hours.
