Size a Cable - Intergraph Smart Electrical - Help - Hexagon

This procedure explains how to size low voltage plant power cables.

1. In the Electrical Index, expand the folder hierarchy Wiring Equipment > Cables > Power Cables. You can also select a cable in the Electrical Engineer.

2. Select the required cable and then select Edit > Common Properties (CTRL+F2).

3. On the General tab of the Cable Common Properties dialog, select the Sizing required check box.

4. Select a cable specification.

   When sizing the cable, the software selects the appropriate reference cable from the family of cables that you specify under Cable specification and with the value that you select under Conductor arrangement.

5. Select the Design Data tab and enter cable length data.

   In the absence of a value for the Design length property, the software uses the value in the Estimated length box.

6. Select the Sizing Data tab and enter data. For full details of the properties for which you must enter values for sizing, see Required Data for Cable Sizing.

7. If the cable has an associated load, you can copy load data to the cable by selecting Refresh Data.

   The software updates the values of the following properties for all item types if these properties have been defined:

   • Full load current (FLA)

   • Starting current

   • Rated voltage

   • Supply (AC/DC)

   • Number of passes

   • Power factor at full load

   • Power factor at starting

8. Select Calculate Sizing to calculate the recommended cable cross-section size.

   After selecting the Calculate Sizing button, the formulas and values used in the cable sizing calculations can be viewed on the Sizing Report tab.

9. Select Apply Sizing to select the recommended reference cable or cables for use as the basis for this cable.

   The software replaces the currently selected reference cable and updates the cable properties.

   If you replace the associated reference cable of a terminated cable, the software does not allow you to resize this cable unless the new reference cable has the same conductor arrangement as the replaced reference cable.

   If you want to use the shipped reference data provided with the application, validate that these values are appropriate for cable sizing. Shipped reference data is provided to you as uncertified samples only.

10. Select Apply to create the sized cable or set of cables in your plant.

• After selecting the Calculate Sizing button on the Sizing Data tab, the formulas and values used in the cable sizing calculations can be viewed on the Sizing Report tab.

• For full details about the properties that you need to enter and the ones that are calculated by the software, see the Cable Common Properties Dialog. You can also edit the most commonly used properties and additional properties in the Properties window or in the EDE.

• After associating a cable with a load, the cable inherits the data required for sizing from the associated load. Note that instruments and cabinets can also function as loads if the Consumer check box is selected on their common properties.

• If you have changed the sizing data of a cable to such an extent that the current cable becomes unsuitable for its function, you need to manually resize the cable (select Calculate Sizing on the Sizing Data tab of the Cable Common Properties dialog). The software informs you about this by displaying an appropriate message in the Calculation information box on the Sizing Data tab of the Cable Common Properties dialog and by turning on the Sizing required flag (the software automatically selects the Sizing required check box on the General tab of the Cable Common Properties dialog). See Automatic Switch-On of the Sizing Required Flag.

• The software does not size a cable for which it cannot find a reference cable with the specified cable specification that matches the value of the minimum conductor cross-section for parallel cables defined in Options Manager. You should either change the value in Options Manager or create a new reference cable with the appropriate cross-section in the Reference Data Explorer.

• The software filters out from the Cable-Sizing Matrix all the reference cables whose insulation voltage rating is smaller than the rated voltage of the current cable. Also, the software does not allow a situation where the insulation voltage rating is smaller than the rated voltage of a given cable. This situation is prevented when:

  • Sizing a single cable or several cables in batch mode.

  • Refreshing load data in batch mode or by clicking the Refresh Data button on the Sizing Data tab.

  • Replacing the associated reference cable of one or more plant cables.

• Manually modifying cable data on the Common Properties dialog box or the Properties window.

• If the software cannot find a single reference cable that is suitable for the needed cable size, it selects as many parallel cables as required, up to the maximum allowed, which you can determine in Options Manager. Also in Options Manager, you can select the minimum conductor size that the software looks for when sizing cables.

• You have to resize a power cable if you reassign it to another load or modify the cable properties. Also, we recommend that you generate a report or use the EDE to view which power cables have their Cable Sizing Flag property set to True (same as the Sizing required check box on the Cable Common Properties dialog. This enables you to see the power cables that need resizing.