Pump Definitions Dialog Box
This dialog box is used to create pump definitions. There are two sections: the pump definition pane on the left and the tab section on the right. The pump definition pane is used to create, edit, and delete pump definitions.
The following controls are available in the pump definitions dialog box:
The tab section includes the following controls:
| Head Tab | This tab consists of input data fields that allow you to define the pump head curve. The specific fields vary depending on which type of pump is selected in the Pump Definition type field. |
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| Pump Definition Type | A pump is an element that adds head to the system as water passes through it. This software can currently be used to model six different pump types: Constant Power —When selecting a Constant Power pump, the following attribute must be defined: Pump Power —Represents the water horsepower, or horsepower that is actually transferred from the pump to the water. Depending on the pump's efficiency, the actual power consumed (brake horsepower) may vary. Design Point (One-Point) —When selecting a Design Point pump, the following flow vs. head points must be defined: Shutoff —Point at which the pump will have zero discharge. It is typically the maximum head point on a pump curve. This value is automatically calculated for Design Point pumps. Design —Point at which the pump was originally intended to operate. It is typically the best efficiency point (BEP) of the pump. At discharges above or below this point, the pump is not operating under optimum conditions. Max Operating —Highest discharge for which the pump is actually intended to run. At discharges above this point, the pump may behave unpredictably, or its performance may decline rapidly. This value is automatically calculated for Design Point pumps. Standard (Three-Point) —When selecting a Standard Three-Point pump, the following flow vs. head points must be defined: Shutoff —Point at which the pump will have zero discharge. It is typically the maximum head point on a pump curve. Design —Point at which the pump was originally intended to operate. It is typically the best efficiency point (BEP) of the pump. At discharges above or below this point, the pump is not operating under optimum conditions. Max Operating —Highest discharge for which the pump is actually intended to run. At discharges above this point, the pump may behave unpredictably, or its performance may decline rapidly. |
| Pump Definition Type (cont’d) | Standard Extended —When selecting a Standard Extended pump, the following flow vs. head points must be defined: Shutoff —Point at which the pump will have zero discharge. It is typically the maximum head point on a pump curve. Design —Point at which the pump was originally intended to operate. It is typically the best efficiency point (BEP) of the pump. At discharges above or below this point, the pump is not operating under optimum conditions. Max Operating —Highest discharge for which the pump is actually intended to run. At discharges above this point, the pump may behave unpredictably, or its performance may decline rapidly. Max Extended —Absolute maximum discharge at which the pump can operate, adding zero head to the system. This value may be computed by the program, or entered as a custom extended point. This value is automatically calculated for Standard Extended pumps. Custom Extended —When selecting a Custom Extended pump, the following attributes must be defined: Shutoff —Point at which the pump will have zero discharge. It is typically the maximum head point on a pump curve. Design —Point at which the pump was originally intended to operate. It is typically the best efficiency point (BEP) of the pump. At discharges above or below this point, the pump is not operating under optimum conditions. Max Operating —Highest discharge for which the pump is actually intended to run. At discharges above this point, the pump may behave unpredictably, or its performance may decline rapidly. Max Extended —Absolute maximum discharge at which the pump can operate, adding zero head to the system. This value may be computed by the program, or entered as a custom extended point. Multiple Point —When selecting a Multiple Point pump, an unlimited number of Flow vs. Head points may be defined. |
| Efficiency Tab | This tab allows you to specify efficiency settings for the pump that is being edited. |
| Pump Efficiency | Allows you to specify the pump efficiency type for the pump that is being edited. The following efficiency types are available: Constant Efficiency —This efficiency type maintains the efficiency determined by the input value regardless of changes in discharge. When the Constant Efficiency type is selected, the input field is as follows: Pump Efficiency —The Pump Efficiency value is representative of the ability of the pump to transfer the mechanical energy generated by the motor to Water Power. Best Efficiency Point —This efficiency type generates a parabolic efficiency curve using the input value as the best efficiency point. When the Best Efficiency Point type is selected, the input fields are as follows: BEP Flow —The flow delivered when the pump is operating at its Best Efficiency point. BEP Efficiency —The efficiency of the pump when it is operating at its Best Efficiency Point. Define BEP Max Flow —When this box is checked the User Defined BEP Max Flow field is enabled, allowing you to enter a maximum flow for the Best Efficiency Point. The user defined BEP Max Flow value will be the highest flow value on the parabolic efficiency curve. User Defined BEP Max Flow —Allows you to enter a maximum flow value for the Best Efficiency Point. The user defined BEP Max Flow value will be the highest flow value on the parabolic efficiency curve. Multiple Efficiency Points —This efficiency type generates an efficiency curve based upon two or more user-defined efficiency points. These points are linearly interpolated to form the curve. When the Multiple Efficiency Points type is selected, the input field is as follows: Efficiency Points Table —This table allows you to enter the pump's efficiency at various discharge rates. |
| Motor Tab | This tab allows you to define the pump's motor efficiency settings. It contains the following controls: |
| Motor Efficiency | The Motor Efficiency value is representative of the ability of the motor to transform electrical energy to rotary mechanical energy. |
| Is Variable Speed Drive? | This check box allows you to specify whether or not the pump is a Variable Speed Pump. Toggling this check box On allows you to input points on the Efficiency Points table. |
| Efficiency Points Table | This table allows you to enter efficiency points for variable speed pumps. This table is activated by toggling the "Variable Speed Drive" check box On. See Efficiency Points Table for more information. |
| Transient Tab | This tab allows you to define the pump's Drainage and Utilities V8i -specific transient settings. It contains the following controls: |
| Inertia (Pump and Motor) | Inertia is proportional to the amount of stored rotational energy available to keep the pump rotating (and transferring energy to the fluid), even after the power is switched off. You can obtain this parameter from manufacturer's catalogs, or from pump curves, or by using the Pump and Motor Inertia Calculator. To access the calculator, click the ellipsis button. |
| Speed (Full) | Speed denotes the number of rotations of the pump impeller per unit time, generally in revolutions per minute or rpm. This is typically shown prominently on pump curves and stamped on the name plate on the pump itself. |
| Specific Speed | Specific speed provides four-quadrant characteristic curves to represent typical pumps for each of the most common types, including but not limited to: 1280, 4850, or 7500 (U.S. customary units) and 25, 94, or 145 (SI metric units). |
| Reverse Spin Allowed? | Indicates whether the pump is equipped with a ratchet or other device to prevent the pump impeller from spinning in reverse. |
| Library Tab | This tab displays information about the pump that is currently highlighted in the Pump Curves Definition Pane. If the pump is derived from an engineering library, the synchronization details can be found here. If the pump was created manually for this hydraulic model, the synchronization details will display the message Orphan (local), indicating that the pump was not derived from a library entry. |
| Notes Tab | This tab contains a text field that is used to type descriptive notes that will be associated with the pump that is currently highlighted in the Pump Curves Definition Pane. |
To create a pump definition
- Select Components > Pump Definitions.
- Click New to create a new pump definition.
- For each pump definition, perform these steps:
- Select the type of pump definition in the Pump Definition Type menu.Type values for Pump Power, Shutoff, Design point, Max Operating, and/or Max Extended as required. The available table columns or fields change depending on which definition type you choose. For Multiple Point pumps, click the New button above the curve table to add a new row to the table, or press the Tab key to move to the next column in the table. Click the Delete button above the curve table to delete the currently highlighted row from the table.
- Define efficiency and motor settings in the Efficiency and Motor tabs.
- You can save your new pump definition in Drainage and Utilities V8i Engineering Libraries for future use. To do this, perform these steps:
- Click the Synchronization Options button, then select Export to Library. The Engineering Libraries dialog box opens. Use the plus and minus signs to expand and collapse the list of available libraries, then select the library into which you want to export your new unit sanitary load.
- Click Close to close the Engineering Libraries dialog box.
- Perform the following optional steps:
- To delete a pump definition, select the curve label then click Delete.
- To rename a pump definition, select the label of the pump definition you want to rename, click Rename, then type the new name.
- To view a report on a pump definition, select the label for the pump definition, then click Report.
- Click Close to close the dialog box.