In many HVAC applications the dampers work in tandem with fans controlled by variable frequency drives (VFD) to regulate airflow. The control of the dampers for these applications is critical whether control originates in the building automation system (BAS) or as proposed in this document, control from the VFD. ABB recommends having the VFD handle the damper control logic, as that allows the logic to be fully functional in both Auto and Hand modes. Damper control schemes handled by the BAS are functional in Auto mode, but often are not functional in Hand mode. Damper configurations in air handling units (AHU) range from a simple isolation damper to more complex systems involving outside air dampers, discharge air dampers, and common plenum systems incorporating multiple fans.
Download this Technical Note to learn how to program the Advanced Damper Control feature in the ACH580 HVAC Drive.
The advanced damper control feature in the ACH580 makes it easy to integrate the damper controls into the VFD by allowing the VFD to initiate the opening of the damper by applying power to the actuator and monitoring the actuator position switches for open and closed status.