The Heating Control with Proportional Valve and Face and Bypass Damper Output Module controls both a proportional valve and a face and bypass damper for either preheat or reheat. The valve is the controlled device if the OA Temperature is above the Switchover Setpoint, and the face and bypass damper is the controlled device if the OA Temperature is less than the Switchover Setpoint. When the valve is in control, the face and bypass damper is 100% face. When the face and bypass damper is in control, the valve is 100% open. The module can be configured for DA-T, RA-T, ZN-T, or PH-T control. The module has been designed with temperature control, low limit control, and protection modes. This module is also designed to control a circulating pump. This module also incorporates tracking the overridden value of the actual output object (AO, PAO). The module resets the PIDs to default tuning parameters if the Reset PID Tuning input is not Normal.
This module provides a second output that incorporates lead compensation to control devices. This function attempts to remove some of the dynamics of the control loop. This process results in forward-looking predictions and speeds up controller responses. The effect is similar to adding derivative action to the controller. Lead compensation is incorporated into most zone temperature control processes where oversized or nonlinear valves might be applied. For more information on the Lead Compensator block, see Lead Compensator in the Control category of the Logic section.
You can view and modify the modules in this group’s logic.