Check that the mechanical system is available, operational, and of the required capacity. Some situations that contribute to PRAC+ tuning problems during construction and system startup include the following:
- The cooling output was controlled when chilled water was not available.
- The heating output was controlled when hot water was not available.
- The VAV boxes or static pressure output was allowed to control when the air system was not running.
- The system does not have the capacity to meet the load.
- Valve installation is incorrect. Valves must be installed in the correct direction, free of debris, powered, calibrated and wired correctly so they can fully open and fully close.
- Damper installation is incorrect. Dampers must be able to open and close, with actuators mounted, wired correctly, and calibrated.
- VFD and PID low limit are set incorrectly. The VFD must be calibrated and in auto. The PID low limit should be set to the minimum output of the drive.
- Sensor installation is incorrect. The sensors must be wired and located properly.