.Buildings.Controls.OBC.ASHRAE.G36.TerminalUnits.DualDuctSnapActing.Subsequences.Overrides

Information

This block considers the overrides to the setpoints for snap-acting controlled dual-duct terminal unit. The implementation is according to the Section 5.11.7 of ASHRAE Guideline 36, May 2020.

Provide software switches that interlock to a system-level point to:

1. when oveFloSet equals to 1, force the zone airflow setpoint VSet_flow to zero,
2. when oveFloSet equals to 2, force the zone airflow setpoint VSet_flow to zone cooling maximum airflow rate VCooMax_flow,
3. when oveFloSet equals to 3, force the zone airflow setpoint VSet_flow to zone minimum airflow setpoint VMin_flow.
4. when oveFloSet equals to 4, force the zone airflow setpoint VSet_flow to zone heating maximum airflow setpoint VHeaMax_flow.
5. when oveCooDamPos equals to 1, force the cooling damper to full closed by setting yCooDam to 0,
6. when oveCooDamPos equals to 2, force the cooling damper to full open by setting yCooDam to 1.
7. when oveHeaDamPos equals to 1, force the heating damper to full closed by setting yHeaDam to 0,
8. when oveHeaDamPos equals to 2, force the heating damper to full open by setting yHeaDam to 1.

Revisions

• August 1, 2020, by Jianjun Hu:
  First implementation.