The Edit Distribution Equipment command is used to change the settings of distribution equipment on the drawing.
If your one-line diagram is based upon a Revit model imported using Design Master Electrical RT, do not use this command. Use the Edit command for Design Master Electrical RT.
To edit distribution equipment, go to
Ribbon: DM Electrical->One-Line Diagram-> 
Edit Distribution Equipment
Pulldown Menu: DM Electrical->One-Line Diagram->Edit Distribution Equipment
You will be prompted to select the distribution equipment to be changed.
Select device to query:
The corresponding distribution equipment dialog box will be opened with that equipment selected. You can then view the equipment and make changes as necessary.