blockEnableLead_dedicated
Sequence to enable or disable the lead pump of plants with dedicated primary chilled water pumps
Information
Block that enables and disables the leading primary chilled water pump, for plants with dedicated primary chilled water pumps and parallel chillers, according to ASHRAE Guideline 36-2021, section 5.20.6.6.
The lead primary chilled water pump should be enabled when the plant is enabled
(uPla = true). It should be disabled when the lead
chiller is disabled (uLeaChiEna = false) and either the lead chiller
has been proven off (uLeaChiSta = false) for 3 minutes or is not
requesting chilled water flow (uLeaChiWatReq = false).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Real | offTimThr | 180 | Threshold to check lead chiller off time |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Buildings.Controls.OBC.CDL.Interfaces.BooleanInput | uPla | True: plant is enabled | |
| Buildings.Controls.OBC.CDL.Interfaces.BooleanInput | uLeaChiEna | True: lead chiller is enabled | |
| Buildings.Controls.OBC.CDL.Interfaces.BooleanInput | uLeaChiSta | True: lead chiller is proven on | |
| Buildings.Controls.OBC.CDL.Interfaces.BooleanInput | uLeaChiWatReq | True: lead chiller is requesting chilled water | |
| Buildings.Controls.OBC.CDL.Interfaces.BooleanOutput | yLea | Lead pump status setpoint |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Buildings.Controls.OBC.CDL.Logical.Latch | leaPumSta | Lead pump status |
Revisions
-
August 1, 2020, by Jianjun Hu:
First implementation.