blockEnableLead_dedicated
Sequence for enabling lead pump of plants with dedicated condenser water pumps
Information
Block that enables and disables the lead condenser water pump, for plants with dedicated condenser water pumps, according to ASHRAE Guideline 36-2021, section 5.20.9 Condenser water pumps, part 5.20.9.4.
The lead condenser water pump should be enabled when the lead chiller is commanded
to run (uLeaChiEna = true). It should be disabled when the lead
chiller is disabled and either the lead chiller has been proven off
(uLeaChiSta = false) for offTimThr, i.e., 3 minutes, or
is not requesting condenser water flow (uLeaConWatReq = 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 | uEnaPla | True: plant is just enabled | |
| Buildings.Controls.OBC.CDL.Interfaces.BooleanInput | uLeaChiEna | Lead chiller commanded on status | |
| Buildings.Controls.OBC.CDL.Interfaces.BooleanInput | uLeaChiSta | Lead chiller proven on status | |
| Buildings.Controls.OBC.CDL.Interfaces.BooleanInput | uLeaConWatReq | Status indicating if chiller is requesting condenser water | |
| Buildings.Controls.OBC.CDL.Interfaces.BooleanOutput | yLea | Lead pump status |
Revisions
-
January 28, 2019, by Jianjun Hu:
First implementation.