Something new in 2010 Electrical is the ability inside of the circuit builder tool to create one-line circuits.
AutoCAD Electrical now provides library support and software support to create motor control one-line diagrams that link back to other drawing types in a project drawing set.

New motor control one-line symbol library accessible from the icon menu.
Circuit Builder supports building motor control one-line circuits dynamically allowing the design of one-line circuits, with component values and wire sizes, to conform to a given electrical code.
One-line component symbols can be related to parent/child counterparts on the schematic and panel layout drawings within a project. You can surf between one-line and related components and all related components update if one is modified.
Tagging of schematic or panel components using existing commands can reference a pick list that includes components pulled from the one-line diagrams.
Certain schematic reports have a new category option. You select the category, for example One-Line, and the data is filtered based on that category. It can also be used to filter a report for Hydraulic, P&ID, or Pneumatic components.