Setpoints and related data
The setpoints and related data include the following items:
- Economizer damper minimum position low speed fan (LowSpeedFan-MinPos)
- Economizer minimum position setpoint (Econ-MinPos)
- FAN control type - fixed variable (FanCtl-Type)
Operation
This function uses the following parameters to determine the economizer minimum position:
- Fan control type = fixed variable (FanCtl-Type)
- Occupied: no heat or cool % command (FanOnly-%Cmd)
- Occupied: one stage of cool % command (1ClgStg-%Cmd)
- Occupied: two stage of cool % command (2ClgStg-%Cmd)
- Occupied: three stage of cool % command (3ClgStg-%Cmd)
- Occupied: four stage of cool % command (4ClgStg-%Cmd)
- Occupied: one stage of heat % command (1HtgStg-%Cmd)
- Occupied: two stage of heat % command (2HtgStg-%Cmd)
- Occupied: three stage of heat % command (3HtgStg-%Cmd)
When the control is in the occupied mode and the FAN output energizes and the VFD output reaches 100%, the economizer damper position is the economizer minimum position setpoint.
When the VFD output reaches the lowest percent command of the parameters above, the economizer damper position is the economizer damper minimum position low speed fan.
When the VFD output is between 100% and the lowest percent command, the economizer damper is positioned proportionally between the economizer minimum position setpoint and the economizer damper minimum position low speed fan.