Wire Sizing

The Wire Sizing command is used to customize the wires used in your project.

To customize the wire sizing tables, go to

DM Electrical->Customization->Wire Sizing

See the General Customization Commands section for more information about how the Edit Project List, Edit Master List, Copy Project List to Master, and Copy Master List to Project commands work.

Wire Sizing Dialog Box

Customization--Wire Sizing Dialog Box

The Wire Sizing dialog box consists of four grids.

The top-left grid is used to specify the sizing options. Each sizing option controls which raceway sizes and breaker sizes are used by default when sizing feeders and branch circuits in your project.

The top-middle grid is used to specify the wire sizes available.

The top-right grid is used to specify the raceway and conduit sizes available. The sizing option controls whether or not each conduit size is used when sizing feeders and branch circuits automatically.

The bottom grid is used to specify the breaker and feeder size available. The sizing option controls whether or not each breaker size is used when sizing feeders and branch circuits automatically.

Sizing Option

This section of the dialog box provides a list of all the sizing options. Each sizing option controls what is used when sizing wires automatically. In the Raceway Area list, the Standard Branch and Standard Feeder columns are based upon the sizing option. In the Breaker list, the Standard Branch Circuit, Equipment Branch Circuit, and Standard Feeder columns are based upon the sizing option. Selecting a different sizing option will change the settings of all of those columns.

Move Up: Press this button to move the selected row up in the Sizing Option list.

Move Down: Press this button to move the selected row down in the Sizing Option list.

New Option: Press this button to create a new sizing option. The New Wire Sizing Option dialog box will appear.

Customization--Wire Sizing.New Wire Sizing Option dialog box

New Wire Sizing Option Name: The name of the new sizing option.

Copy Sizing Information from this Option: The sizing option to copy settings from. It sets the starting values for the columns the sizing option controls.

Delete Option: Press this button is delete the selected sizing option.

Sizing Option: The name of the sizing option. The name is shown at the bottom of the feeder schedule.

The default wire sizing table is set up using copper conductors, rigid steel conduit, and references NEC Table 310.16, 60 degree C #12 through #1, 75 degree C 1/0 and above.

Current: The sizing option that is currently active in the project. Branch circuit and feeder sizes are chosen based upon the settings of the selected sizing option. Only one sizing option can be active in a project at a time.

Wire Size

This section of the dialog box provides a list of all the wire sizes.

New Wire Size: Press this button to create a new wire size. It will be added to the bottom of the list when it is created. When you close and reopen the dialog box, the size will be sorted to the correct location in the list based upon the area.

Delete Wire Size: Press this button to delete the currently selected wire sized.

Undo Wire Changes: Press this button to revert the wire size settings to their values when the dialog box was opened.

Wire Size: The name of the wire size. This label is shown in the wire callout.

Schedule Label: The label for the wire size when it is shown in a schedule. The wire size can be shown in the panel schedule, fault schedule, and voltage drop schedule.

Wire Area: The area of the wire, in square inches. See NEC Table 5. Used to calculated the conduit fill.

Raceway Size

This section of the dialog box provides a list of all the raceway sizes.

New Raceway Size: Press this button to create a new raceway size. It will be added to the bottom of the list when it is created. When you close and reopen the dialog box, the size will be sorted to the correct location in the list based upon the area.

Delete Raceway Size: Press this button to delete the currently selected raceway.

Undo Raceway Changes: Press this button to revert the raceway settings to their values when the dialog box was opened.

Raceway Size: The name of the raceway size. The raceway size is included at the front of wire callouts that include conduit.

Raceway Area: The area of the raceway, in square inches. See NEC Table 4. Used to calculated the conduit fill. Conduits are sized automatically so that the maximum fill is 40%, as specified in NEC Table 1.

Standard Branch: Whether or not the raceway size is used when automatically sizing branch circuits.

Standard Feeder: Whether or not the raceway size is used when automatically sizing feeders.

Breakers and Conductors

This section of the dialog box provides a listing of the breaker sizes and corresponding conductors.

Multiple breakers of a single size may be included in the list. One breaker can be the default used when sizing branch circuits and feeders automatically. The other breakers can be chosen when sizing them manually.

Move Up: Press this button to move the selected row up in the Breakers list. Breaker sizes can be moved within the breaker of the same size. You cannot move breakers so that the sizes are no longer in numerical order.

Move Down: Press this button to move the selected row down in the Breakers list. Breaker sizes can be moved within the breaker of the same size. You cannot move breakers so that the sizes are no longer in numerical order.

New Breaker: Press this button to add a new breaker.

Delete Breaker: Press this button to delete the selected breaker.

Undo Breaker Changes: Press this button to revert the breaker settings to their values when the dialog box was opened.

Amperage: The breaker size.

Wire Size: The size of the phase wires for the breaker. The list of wires is set in the Wire Size section of the dialog box.

Service Ground: The size of the service ground for the breaker. This sizing should be selected based on the NEC for service ground sizing. The list of wires is set in the Wire Size section of the dialog box.

Equipment Ground: The size of the equipment ground for the breaker. This sizing should be selected based on the NEC for equipment ground sizing. The list of wires is set in the Wire Size section of the dialog box.

Parallel Runs: The number of parallel runs of conduits for the breaker. Each run contains the same size wires.

X: The reactance of the breaker. See NEC Table 9 for values. The reactance needs to include an adjustment for the number of parallel runs.

R: The resistance of the breaker. See NEC Table 9 for values. The reactance needs to include an adjustment for the number of parallel runs.

Standard Branch Circuit: Whether or not the breaker size is used when sizing standard branch circuits. Only one breaker of each size can have this box checked. You do not have to have it checked for each size breaker. It is possible to include breaker sizes that are not sized to automatically.

Equipment Branch Circuit: Whether or not the breaker size is used when sizing branch circuits based upon the MCA and MOCP of equipment connected to them. Only one breaker of each size can have this box checked. You do not have to have it checked for each size breaker. It is possible to include breaker sizes that are not sized to automatically.

Standard Feeder: Whether or not the breaker size is used when sizing feeders to one-line devices. Only one breaker of each size can have this box checked. You do not have to have it checked for each size breaker. It is possible to include breaker sizes that are not sized to automatically.

Include Conduit: Whether or not the wire size label for this breaker includes the conduit size.

Description: A label used to differentiate the breakers of the same size in the pulldown lists in other dialog boxes. When choosing a custom breaker, the list will include all of the breaker sizes. If there are two definitions of the same breaker, there is no way to tell them apart. The description is added after the breaker size in the list to help you choose the correct breaker. The description is never displayed on the drawing.


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