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Fault Calculations

This tutorial teaches you how to perform a fault calculation on your electrical system.

Open drawing E-4.2.

Insert the Fault Schedule​

  1. Run the Insert Fault Schedule command. The Fault Current Schedule dialog box will open.
    Ribbon: DM Electrical→Distribution Equipment→  Insert Fault Schedule
    Pulldown Menu: DM Electrical→Distribution Equipment Schedules→Insert Fault Schedule

    note

    You can use this dialog box to customize the appearance of the fault current schedule. For this tutorial, we will leave everything as it is.

  2. Press the button to close the dialog box.

  3. Follow the prompts at the command line to place the fault schedule on the drawing.

Once the schedule is inserted, you should get a dialog box that says "Errors occurred during calculations" and an X should be drawn over the schedule. These warnings indicate that additional information is required before the calculation will work. Additional details about how to fix the errors are displayed on the command line.

You should have a single error related to the feeder length for panel H1. This error can be fixed by inserting the upstream transformer UTIL on the drawing or by manually entering the feeder length. We are going to solve the error by manually entering the feeder length.

Set the Feeder Length to H1​

  1. Run the Panels command. The Panel dialog box will open.
    Ribbon: DM Electrical→Distribution Equipment→  Panels
    Pulldown Menu: DM Electrical→Distribution Equipment→Panels

  2. Go to panel H1. You can do this using the and buttons or the button.

  3. In the Fault Analysis section, press the button.

  4. Set Feeder Length Calculation Method ▾ to Custom.

  5. Set Feeder Length to 100.

  6. Press the button.

  7. Press the button.

  8. Press the button.

  9. Run the Insert Fault Schedule command. The Fault Current Schedule dialog box will open.
    Ribbon: DM Electrical→Distribution Equipment→  Insert Fault Schedule
    Pulldown Menu: DM Electrical→Distribution Equipment Schedules→Insert Fault Schedule

  10. Press the button.

The fault schedule will be updated in its current location on the drawing. It should insert without any warnings this time.

Set the Starting Fault​

Typically, you are provided a starting fault value by the utility company. That value can be set in the first piece of distribution equipment in your electrical system.

  1. Run the Edit Distribution Equipment command.
    Ribbon: DM Electrical→Distribution Equipment→  Edit Distribution Equipment
    Pulldown Menu: DM Electrical→Distribution Equipment→Edit Distribution Equipment

  2. Select UTIL.

  3. Press the button. The Transformer dialog box will appear with UTIL active.

  4. In the Fault Analysis section, check the box next to the button. The Lock Fault dialog box will appear.

  5. Set Fault to 65000.

  6. Press the button.

  7. Press the button

  8. Press the button.

  9. Run the Insert Fault Schedule command. The Fault Current Schedule dialog box will open.
    Ribbon: DM Electrical→Distribution Equipment→  Insert Fault Schedule
    Pulldown Menu: DM Electrical→Distribution Equipment Schedules→Insert Fault Schedule

  10. Press the button.

The fault schedule will be updated in its current location on the drawing again. The values in the schedule will be updated to reflect the new starting fault.